If the state Senate approves the measure, it would then go before voters in April. If they pass it, Virginia would join the wave of mid-decade redistricting that has swept the nation since Texas started it all last August at President Trump’s direction. It would be the largest development since California’s Proposition 50, which replaced that state’s Congressional map for the 2026-2030 elections and provided a counterweight for the Texas plan.

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Multiseat gains: Texas, California, and now Virginia?

Over the last half year only two states drew maps that would produce more than one seat: Texas and California. Now comes a third state, Virginia.

Virginia currently has a party-neutral map and a Congressional delegation of 6 Democrats and 5 Republicans. Because the map has considerable competition (reflected in the Princeton Gerrymandering Project’s grade of A), there is potential for Democrats to gain in 2026. Already, District 2 is at risk for Republicans, and Districts 1 and 5, also held by Republicans, are at least competitive. At maximum, that would lead to a 9 Democrat, 2 Republican delegation simply through normal campaigning.

But the Virginia legislature is not aiming for the playing field to be level. Instead, they want to extract partisan advantage by drawing a new map, and gain up to four guaranteed seats. However, that comes at a cost: disruption for voters.

Letting politicians pick their voters

By definition, redistricting moves people into new districts. As documented for Ohio, Texas, and California, an aggressively partisan map can typically displace one-third of voters. Those voters are guaranteed to get new representatives who do not necessarily know their priorities or needs. And in a partisan gerrymander, voters get a new representative even if they haven’t been moved.

As it turns out, an aggressive gerrymander could give nearly two-thirds of Virginians either a new district, a new representative, or both.

First, let’s look at the current map, which is a model of good design that arose from the work of the Virginia State Supreme Court. As Zachariah Sippy and I have found in our survey of all 50 states, there are two ways that a redistricting process is guaranteed to lead to a good outcome, as measured by the metrics of the Princeton Gerrymandering Project. The first is an independent commission. The second is a state or federal court that takes over the task of drawing the lines itself.

In a sense, Virginia did both. Their commission deadlocked because half of its membership were politicians, who couldn’t agree despite the best efforts of the citizen members to make a deal. That failure threw the whole process to the state Supreme Court. The state Supreme Court proceeded to appoint two special masters to do the job, Bernie Grofman and Sean Trende. Those two worked together to create a map that treated both parties in a balanced manner and preserved many communities. In their plan, out of 11 districts, 3 are expected to be competitive within a 10-point margin, which is phenomenally good.

However, rather than gain seats by fair competition, the Virginia legislature appears to be considering the possibility of forcing the outcome through gerrymandering. They are discussing drawing a map that would guarantee them 9 or even 10 Democratic seats. But the more seats they draw for themselves, the more voters they have to displace.

At the Electoral Innovation Lab, we have surveyed a variety of maps drawn by users over at Dave’s Redistricting App. By looking at those maps, we can get a sense for how many people need to be moved into a new district in order to create partisan advantage.

DRA is a redistricting tool that is used by both professionals and people with a recreational interest in the subject. DRA is free, and has given rise to a whole industry of “redistricting hobbyists.” Some of these hobbyists are quite serious: one DRA user’s work was chosen by a court for use in Alabama’s new political maps.

Different map drawers show different levels of attention to preserving existing districts. We surveyed them all, and flagged the ones with least disruption.

Going from 6 to 9 Democratic seats requires moving one-fourth of Virginians

Below are two maps. On the left is current map. On the right is a map drawn by DRA user waterrs20. It leads to 9 Democratic congressional seats.

The map by waterrs20 moves 27% of people into a new district. If you count all of the people in the districts where partisan control would likely change, the fraction of people who will have a new representative goes up to 43%. So nearly half the state will get new representation in order to gain just one more seat above what might otherwise happen without any changes.

Getting to 10 Democratic seats requires moving nearly half of residents

Some legislators in Virginia are considering taking even more aggressive steps. State lawmakers, including the House Speaker Don Scott and state Senate President pro Tempore L. Louise Lucas, have said they favor drawing a map that elects 10 Democrats and 1 Republican. Several DRA hobbyists have done this. All maps are disruptive, but among the less disruptive ones is one drawn by Stephen Wolf.

This map moves nearly half - 47% to be exact - of Virginians into a new district. Because it leads to 4 districts changing partisan hands, the number of people who will have a new representative is even greater: 63%. Therefore, nearly two-thirds of Virginians would have a new representative under this map:

The legislature plans to produce a sample map in advance of the April referendum so that voters can see what they are getting. Given the analysis that we have done, the more seats they wish to shift, the more disruption will be necessary.

Finally, here is a graph summarizing a large number of plans in Dave’s Redistricting App. The red line indicates the least disruption, counting people moved into a new district. The black line includes the entire district population of districts that would change partisan hands. Both graphs start at zero for the current 6-5 plan.

It seems likely that this initiative will be enacted. In California, Proposition 50, which allowed a 5-seat gerrymander gained by Democrats, passed along largely partisan lines. Virginia is likely to do the same. That means that the degree of disruption is in the hands of the legislature.

The state of play: continued stalemate

Here is an updated table of likely outcomes based on what has happened so far and what may happen in the future.

The Virginia gerrymander would be likely to equal any partisan gains from redistricting in Florida, which is expected to occur in the next few months. Together they would eliminate competition in half a dozen Congressional districts.

This is the cost of partisan gerrymandering: little net benefit to either major party, but considerably reduced competition. A better outcome would be a cease-fire, in which neither state redraws its map.

Thanks to Neil Dixit for enabling an estimate of the 8-3 map.

Well, they didn’t do it.

When given an extreme map even by current standards, Indiana state Senate voted down the mid-decade gerrymander. The final vote was 31 no, 19 yes. Among the 31 noes were 21 of the 40 Republicans in the state Senate. This happened just an hour ago!

As I wrote before (and reprinted* in the Terre Haute Tribune-Star), this is actually in Indiana Republicans’ self-interest. The map would have moved 36% of Hoosiers into a new district - a major disruption. Despite radical threats from Trump to withhold federal aid from Indiana, and despite visits by Vice-President JD Vance, the state Senate left in place a map that elects two Democratic Representatives, including one from the city of Indianapolis. Indiana is now hedged against the probability that next year, Democrats will retake control of Congress.

With that, the redistricting wars are back at a stalemate, at least given current trends in public opinion.

It’s looking like the redistricting wars are slowing down, at least today. Some of this cooling may arise from recognition that control of Congress is slipping away in 2026. That’s a practical reason, not a principled one. But it’s still worth celebrating.

*I’m from Terre Haute long ago. It was a particular pleasure to publish in the hometown paper!

Gerrymandering is terrible, a blight on democracy, blah blah blah. We all know this song. It is a true song, but stop for a moment.

Today I want to make a new point: drawing a gerrymander in Indiana will hurt Hoosier Republicans’ self-interest.

What happened in Indiana?

Yesterday the Indiana House voted for a new Congressional map. This is the latest in a series of unprecedented anti-democracy offenses across the nation. The next step is for the state Senate to vote on the plan. But if they approve the map, they will shoot themselves in the foot. The reason is that considering likely electoral dynamics in 2026, they will freeze their state out of influence in the next Congress.

Indiana’s hedge against national partisan change

Indiana’s current Congressional map elects 7 Republicans and 2 Democrats to the House of Representatives. One Democratic district encompasses most of Indianapolis, the state capital; the other, the northwestern corner of the state, including Gary. The remaining 7 districts cover a variety of communities in what has become a strongly right-leaning state. In this way, Indiana has bipartisan representation in Washington, D.C.

Politics as self-interest, rightfully conceived

In a deep sense, a split delegation like the existing map is good for democracy. Politics is the art of self-interest, rightfully conceived. Redistricting isn’t just about raw national power. It’s also about making sure communities and groups are represented. In the American system, single-member districts have to do three jobs: (a) in individual districts, represent local geographic communities, (b) at a statewide level, represent the state as a whole, and (c) at a national level, represent the political parties, racial groups, and other forms of issue diversity. As of today, Indiana’s map contributes to all three forms of representation.

But the gerrymandering wars have put national partisanship above everything else. Mathematically, we can imagine this extreme state of affairs as a situation in which politicians see citizens only as partisans. If politics is a complex landscape, it is like citizens are forced to choose between just two mountains on that landscape. I spoke about this here:

A healthy democracy is higher-dimensional: our political processes would reflect a variety of competing interests. But that’s not what the Indiana House has in mind.

Their new map builds on the reliability of voters who are stuck choosing between the two mountains, and whose choices are therefore easy to predict. The resulting map is designed to produce an all-Republican, 9-0 delegation. It would carve up Indianapolis into four parts, eliminating any hope of getting the city representation in Congress; and similarly split northwestern Indiana. Overall, this map would move 36% of the people of Indiana - more than 1 out of 3 - into a new Congressional district - m.

After Texas, this is the only multi-seat gain for Republicans to come from mid-decade redistricting. (Missouri and North Carolina gain them one seat each.) The Princeton Gerrymandering Project has scored the new proposed map as an “F” (in contrast to the current map, which gets an “A”).

You might think this is a win for Republicans; certainly Donald Trump has hailed it as one. But by enacting such a lopsided map, Hoosiers are about to deal themselves out of national power.

The reason is that in the House of Representatives, the singular operating rule is: the majority makes the rules. If control of the House changes hands in the 2026 election, somebody in the state’s delegation can speak up for Indiana’s interests. And with no Democrats from Indiana, such a change of control is potentially disastrous for the state.

Special elections in 2025 favor Democrats by double digits

Another piece of news this week brings that scenario into sharp relief: the special election in Tennessee’s 7th District. That election reveals voter sentiment in a way that reveals mid-decade redistricting as a desperate attempt to bail out a leaky boat, in the face of an incoming tidal wave.

Reporters and the politically interested have focused on last week’s special election in Tennessee’s 7th District as a predictor. TN-7 was drawn to be safely Republican back in 2022, by splitting greater Nashville (Davidson County) across three districts. In 2024, two winning Republican candidates, President Trump and Senator Marsha Blackburn, won this district by 22 points. Normally, pundits would call that a safe Republican seat. But this week, Republican candidate Matt Van Epps came out only 9 points ahead of Democrat Aftyn Behn - a 13-point underperformance.

Special elections like this one can be used to detect shifts in opinion and partisan enthusiasm for voting. Over the last 8 years, special elections (state, Congressional, etc.) come within a few points of predicting the partisan vote in the next Congressional election. As tracked by The Downballot, the Tennessee election is at the average of 60 special elections in 2025: a median 13-point overperformance for Democrats compared with the 2024 Harris-vs.-Trump margin.

A swing of even 2 points will give the House to the Democrats

Depending on how much overperformance occurs, Democrats can expect more seats compared with the 2024 result. This can be calculated by applying an equal amount of overperformance (”swing”) to all Congressional districts. It is also possible to apply this swing to include the new maps, which now include TX/CA/MO/NC/OH/UT/LA/IN. The actual swing will vary across districts, but this is a good approximation to what will happen next year.

The hypothetical results look like this:

In this table, the zero-swing entry of 215 seats is just the actual number of seats won by Democrats in 2024.

Let me walk you through this table. First, let’s ask what all the mid-decade redistricting amounts to.

Under these assumptions it would have taken a 1.2-point swing under the old maps for Democrats to get 218 seats, the number needed for a majority. That was a really close election. Now, after all the redistricting, the net effect is to raise the necessary amount of swing from 1.2 points to 2.0 points. For perspective, the Great Gerrymander of 2012 would have required nearly a 5-point swing. 2012 remains the high-water mark for extreme gerrymandering in modern times, and all the shenanigans we’ve seen don’t come close to it. That’s because of independent citizen commissions (minus the temporary suspension of the California commission) and actions in state court. In short, the gains from mid-decade redistricting are fairly paltry.

Second, any realistic swing at all in voter opinion will hand the House of Representatives to the Democrats. I would personally guess 10 points, which would be a 22-seat gain under the old maps.

The new maps will reduce that 22-seat gain...to 21 seats. After all the gerrymandering actions, the gain is only one seat. All that fuss, for a little bit of power.

Dummymandering for dummies

Finally, this is interesting: If the swing gets up to 12 points or more, the partisan advantage actually reverses. Democrats start winning more seats under the new maps than under the old maps. This effect, which arises from cutting things too close with a gerrymander, is called a dummymander. Given current trends, prime candidates for dummymanders in 2026 include Texas and North Carolina.

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Note that things could be even worse for Republicans. This calculation doesn’t even take into account that Hispanic voters appear to have swung much more than other voters. Because of that, in Texas they might not gain even one seat compared with 2024, which was a more cautious gerrymander that gave them 26 out of 38 seats in 2022 and 2024.

Based on all of this, the odds are very strong that changes in voter sentiment are enough to hand the House of Representatives to Democrats. In such a scenario, the Indiana Senate might serve their state better by declining to enact the state House’s handiwork.

Conclusion

If Indiana Senate wants to look out for their own state’s fortunes in Washington next year, they might consider declining to join this year’s national festival of gerrymandering.

The redistricting wars just might be winding down. Things were already looking weak for the Republicans purely based on the smallness of the gains. But today’s court ruling feels like a nail in the coffin. Understanding what’s going on requires getting into the weeds a bit, so let’s start with yesterday’s court ruling.

The worst gerrymander of modern times dies in court…

Whenever a Congressional redistricting case lands in court, federal law requires that the case be heard by a panel of three judges. Today, such a panel ruled to overturn the plan enacted by Texas Republicans in August. As I have written, this plan is the all-time worst gerrymander in the modern era of voting rights.

The opinion was authored by Judge Jeffrey Brown, who was appointed by President Trump in 2019. Judge Brown based his ruling (the full text is here) on the grounds that the plan was drawn improperly because it was done principally for racial reasons. (The Department of Justice had issued an opinion saying this was necessary, and Governor Abbott had cited this statement.) Such a theory is based in the Constitution, and so precedes the Voting Rights Act.

In other words, an improper instruction from the Trump Department of Justice to use race led a Trump-appointed judge to strike down a plan demanded by Trump himself. It seems like a lot of self-immolation.

If this decision holds up, it might dampen the enthusiasm of Florida Republicans. They have been considering mid-decade redistricting, but they have been dragging their heels. I would not be surprised if they gave up.

Those grapes were probably sour anyway

Even before today, the Texas gerrymander was already looking like a strategic blunder. Legislators use redistricting to collect voters for maximum advantage. The 2021 Texas Congressional map was already an extreme partisan gerrymander: the Princeton Gerrymandering Project tagged it as an outlier and gave it a grade of F. That map, which recently elected 25 Republicans and 13 Democrats, already gives Republicans 3 excess seats over what a neutral process would produce. Against that backdrop, squeezing out more seats was technically difficult to achieve. But the Texas Legislature tried.

They did so by breaking up various racial communities in the state. The resulting map looked like it would produce up to 5 more seats if voters cast ballots as they did in the 2024 presidential election, when Trump made major inroads among Texas Hispanics voters. Combined with the 3 extra seats it had before, that’s an aspirational goal to steal 8 seats. No Congressional map in any state has ever achieved such a large gain.

The new map was at high risk of failing to deliver, in large part because of Hispanic voters. Opinion surveys have been showing that this community has swung hard against Republicans, and New Jersey’s gubernatorial election results confirmed it. Democrat Mikie Sherrill’s 13-point win over Jack Ciattarelli was a 7-point improvement over Kamala Harris’s margin in the 2024 Presidential race. But she improved by more like 60 points among Hispanic voters

That is just an astounding level of movability, eight times that of the rest of the population.

We also know that many Texas Hispanic voters can favor either party. They also swung toward Trump in 2024, yet in several districts that voted for him, Democratic Congressmen were also re-elected. So there was a risk that the Texas map would not produce the gains they thought it would. As I wrote in July, the plan could backfire spectacularly, with an outside chance that Republicans could even lose up to two seats. I stand by that estimate.

How much juice was in the lemon?

Electoral Innovation Lab/Princeton Gerrymandering Project collaborator Prof. Jonathan Cervas compared the old and new maps using a variety of past election data. He calculated how either map would perform under the same spatial pattern of voters. The results are below.

He found that the benefits were not that large: only 3.3 additional seats, on average.

Of particular note, the gains are not reliable. A standardized measure of reliability is the standard deviation, which is a yardstick for how far an individual outcome can stray from the average. Normally a gerrymander makes the standard deviation smaller, i.e. more reliable. In this case, the standard deviation got larger, going from 1.0 seat to 1.5 seats.

I estimate that because of swing among Hispanics, six districts in the mid-decade gerrymander would be competitive: Districts 9, 15, 23, 28, 34, and 35. Most of these districts are near the southern border. If all of them went Democratic, which is an outside possibility in 2026, that would lead to a total of 14 seats, one more seat than they won last year. (District 32 is also a possible second backfire district.)

That’s an extreme case. I would guess that if this map were in place in 2026, it would produce a gain of about 2 seats for Republicans.

All this is to say that Texas legislators did not do a very secure job of gerrymandering their state. Yesterday’s court decision could be seen as striking down a risky gerrymander whose main feature was to attack Hispanic representation.

…but the second-worst gerrymander ever, in California, in on track

Still left standing is the other giant gerrymander of the year, Proposition 50. California voters passed it overwhelmingly, by a margin of nearly 30 points. According to its final text as enacted, It was originally conceived as a response to the Texas gerrymander. However, the final language of Proposition 50 only says “In response to the congressional redistricting of Texas in 2025”:

It is not predicated on what Texas actually did. So even if the Texas map is struck down, the California map still has a high likelihood of being used in 2026.

California gerrymander: a gain of 5 seats in 2026

Jonathan found that the California map performs more consistently than the Texas gerrymander. One reason is that the California map was relatively neutral to begin with. Although some Republican partisans had claimed that it was a partisan gerrymander, it was entirely consistent with results from party-neutral computer simulation. And it had lots of competitive districts: in 2024, nine Congressional elections were decided by margins of less than seven points.

The passage of Proposition 50 introduced a large partisan advantage and mowed down competition. It shows what an actual extreme pro-Democrat gerrymander looks like. In this case, the lemon contains considerable juice.

The commission-drawn map would have produced an average of 40.8 seats, whereas the Proposition 50 map would have produced 47.1 seats. The 6.3 seat difference is quite large. The standard deviation goes from 2.9 seats to an amazingly small 0.7 seats, a major tell of a secure gerrymander. Graphically, you can see the change here:

With current levels of unpopularity for the Republican party, the 2026 election might send 48 California Democrats to Congress, and only 4 Republicans. That’s a gain of 5 seats over the current 43 D, 9 R split.

The California map is also being challenged in court on grounds of impermissible use of race. But as Matthew Cooke and Rick Hasen point out over at Slate, the evidence is weak. The map will probably withstand the challenge.

The state of play: Republicans fall behind

As Donald Trump’s power over his party weakens, the tick, tock of mid-decade redistricting has slowed down. It looks like Indiana isn’t going to redistrict anytime soon, and even Florida might not. At the moment, the net advantage goes to Democrats, at least in terms of seats.

Assuming the Texas map is struck down and the California map stands, we would have the following state of affairs: gains from new district maps in Missouri (1 seat), Ohio (1 seat on average, but with more competition), and North Carolina (1 seat) totaling 3 seats for Republicans; versus gains for Democrats arising from Utah, where a court struck down a partisan gerrymander, and the aforementioned five seats in California, totaling 6 seats for Democrats. The net effect of this festival of gerrymandering and de-gerrymandering so far is a gain of three seats for Democrats.

What really matters: voter opinion and election vulnerability

It is important to remember that this is only part of a larger picture. A gain of a few Congressional seats is quite small compared with the high likelihood of 20 to 30 seats changing hands next year. Mid-decade redistricting was never going to exceed that amount.

If current trends (TX struck down, MO encountering resistance by citizens, KS, MD, and IN legislators dragging their heels) continue, then the ideal case would be for everyone to see that this is a fruitless war. The 2026 election should seal the case. Then we can get back to long-term reform and repair to our democracy.

More importantly for 2026, redistricting reduces competition, voter choice matters in fewer district. As a consequence, the remaining competitive districts are an easier target for interference. We’ll get into that in a future post.

Hopefully this ends a years-long saga in which legislators have been looking for a way to re-take some of the power of line-drawing from the citizens who took it from them in 2018 via Proposition 4. If the new ruling stands, Utah voters will likely end up electing 3 Republicans and 1 Democrat to Congress next year.

Here’s the full text of my piece:

Is this the end of the road for redistricting battles in Utah?

by Sam Wang

Yesterday, a state judge in Utah struck down moves by the Legislature that many saw as the latest partisan gerrymander. If the court’s replacement map holds, there is a glimmer of hope that a yearslong, charged political tale may soon end.

This decision was the latest ruling that centers on a law that Utah citizens passed to wrest the redistricting power away from legislators. Passed in 2018, that law, Proposition 4, gave citizens a say in the process and put in place a prohibition on partisan gerrymandering.

This did not stop the Legislature. Instead, they attempted to replace the law entirely. However, the court found that this took away the people’s own legislative power as described in the Utah Constitution.

Judge Dianna Gibson nonetheless gave the Legislature a shot at making amends for its offense. But yesterday, she found that the new map still violates Proposition 4, by unduly shutting out Democrats.

In some states it’s extremely hard to elect even one member of the minority party. Mathematicians have proven that in Massachusetts, Republicans are so evenly spread around the state that there’s no way to draw even one district favoring them. Conversely, in Oklahoma, one-third of voters routinely choose Democratic candidates, but I can’t see any way to draw a district that favors them. In some states, geography is destiny.

However, Utah is different. Metropolitan Salt Lake City, which contains 1.3 million people, is more than large enough and liberal enough to elect one Democrat. But creative line-drawing by the Legislature cut up this region and gave pieces to every corner of the state, leading to the production of four mini-Utahs, each guaranteed to elect a Republican.

Basically, the Legislature seemed to be executing an old strategy in the gerrymandering playbook: splitting voters with shared interests into groups too puny to elect anyone.

Computer simulations show that a party-neutral process is highly likely to create a district that Democrats can win. In contrast, the Legislature’s plan was a statistical outlier.

By recognizing this fact, the court overrode a recently-enacted Utah law that called for districts to be clustered around the statewide average. In a state like Pennsylvania, where Democrats and Republicans are equally divided, such a rule might treat the parties equally. But forcing Pennsylvania-like standards onto Utah politics is like forcing somebody else’s foot into Cinderella’s slipper. This mathematical jiggery-pokery seemed to some observers a move to thwart the intent of Proposition 4.

What’s next for Utah? In August, Judge Gibson found that under the Utah Constitution, the power to make laws lies jointly between the people and their elected representatives. According to the judge, the people’s expression of that power can be modified, but not overridden entirely. So assuming that ruling holds, Utah will at last have a citizens’ commission in 2031.

Until then, a temporary map is needed. Yesterday, the court accepted a map proposed by citizen plaintiffs that reunites greater Salt Lake City in one district, and creates three surrounding districts that reflect different regions of the state. In 2026, such a map would likely elect a delegation of one Democrat and three Republicans, reflecting the diversity of the Beehive State.

Meanwhile, the national redistricting wars are currently at a stalemate. In the last three months, four states have replaced their congressional maps mid-decade: Texas, California, Missouri and North Carolina.

All told, millions of voters in both parties will be newly deprived of any influence in the next three congressional elections. But as terrible as these wrongs are, at least they balance one another out. As it stands, 2026 elections are still likely to elect a House of Representatives that reflects the will of Americans as a whole.

Thankfully, the festival of gerrymandering may be winding down. A redistricting commission in Ohio reached a bipartisan compromise, and legislators in Kansas and Indiana are dragging their feet about meeting President Donald Trump’s demands to carve up their population like a Thanksgiving turkey.

There is some hope that the next election will elect a Congress that, in many districts, is decided the old-fashioned way: by candidates appealing to voters and voters casting ballots.

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A national stalemate

In other news, the approval of Proposition 50 in California will lead to a net gain of about 6 seats for Democrats. Combined with Utah, the advantages gained by Republicans in Texas, Missouri, and Ohio are fully neutralized - but at the cost of reduced competition.

The scorecard above illustrates where we’re at. Jonathan Cervas and I are brewing up some analytics to break down this new stalemate. We’ll write about it soon.

We’ll talk about gerrymandering, where things stand as of this week, and what it means for Election 2026 - not just Congressional power, but new vulnerabilities that arise from reduced competition. DOJ in California, National Guard/ICE in Texas.

In the meantime, here’s something new: I’ll be on Heather Cox Richardson’s podcast this coming Monday, November 10, at 11:00am Eastern / 8:00am Pacific. The guests are me and Kate Compton Barr, Congressional candidate in the 14th District of North Carolina.

It will be recorded too. Please listen, live or recorded, by clicking the image below!

Greetings from high above America. I’m goin’ to Kansas City!

Tonight I’m appearing on a panel at the Kansas City Public Library to talk about mid-decade redistricting in Missouri and Kansas. Together, they might give Kansas City a pummeling - and leave an urban area that spans two states with no representation in Congress.

First, the key detail for Missouri/Kansas locals: the Community Q&A is today at 6:00pm at the Kansas City Missouri Public Library on Plaza Street. It’s hosted by KCUR’s Steve Kraske. Come on out!

Others across the nation: tune in on YouTube! 4pm Pacific, 6pm Central, 7pm Eastern.

Missouri, Gateway to Gerrymandering

Missouri has recently enacted a mid-decade Congressional map. It radically changes District 5, which Emanuel Cleaver has represented since 2005.

This month, Governor Mike Kehoe called the legislature into session. His stated reason was to make the districts more compact. However, here is the old map:

That little blue patch to the west is District 5. It contains Kansas City, which is Missouri’s largest city.

Now look at the newly enacted map:

District 5 got a lot larger, less compact, and has turned red in the Princeton Gerrymandering Project map. Black communities in Kansas City are carved off and combined with areas to the east, past Jefferson City and all the way to tiny Freeburg, over 180 miles away. Those areas are quite dissimilar to Kansas City in racial composition, industry, and voting habits.

Here’s a precinct-level view, showing how Kansas City has been split by race:

The claim of increasing compactness doesn’t hold up that well: the new District 5 is far more extended and oddly shaped, and over metrics of compactness are about the same as the old map.

Missouri voters have challenged this law through multiple lawsuits in state court, the only realistic route they have. They say that under the state constitution, mid-decade redistricting is forbidden, and that the new plan violates compactness requirements. Here is one easy-to-read legal brief.

Nationwide, Democrats are likely to pick up dozens of seats in 2026, so an effort to pick up one district seems like fighting the tide, while also destroying representation for Missouri’s largest city.

At tonight’s panel I will delve into the data. There will also be a panelist arguing in favor of this new map, as well as journalists to give details. A comprehensive discussion!

Kansas: Carry On, Wayward Legislature

On the other side of the state border, a somewhat lesser story is brewing: the legislature is considering redrawing the Kansas Third District. Pulling off that particular shenanigan faces multiple barriers:

• The legislature has to hold together its supermajority to overcome the veto of Democratic governor Laura Kelly.

• Sharice Davids, the Democratic incumbent, has bipartisan appeal and will be hard to displace.The new district will have to split Johnson County, Kansas’s most populous county, into three parts, and to displace Davids, her new district will probably have stretch most of the way to Colorado.

All in all, it seems like a long shot. Anyway, we can talk about it tonight as well.

P.S. Post-event:

First, the immediate news that everyone knows: It’s been a rough week for fair districting. This week’s Supreme Court oral argument in Louisiana v. Callais made clear that Section 2 of the Voting Rights Act is on the ropes. This part of federal law protects the ability of racial minority groups to have a chance at representation. Remarks by Roberts, Kavanaugh, and Barrett, the centermost three justices, make their thinking clear. Black, Hispanic, Asian, and coalition districts will be on the chopping block.

The eventual Supreme Court decision probably won’t come until June. So the consequences for elections might not become clear until after 2026. Also, it should be noted that some of the consequences have already been in the news. For example, Texas’s new Congressional map dismantled four districts where Black and Hispanic populations could elect members. In other states like Mississippi, it is not clear that they can or will act in time for the 2026 election. So as bad as this is for those communities, it may take time to find out just how bad.

In the meantime, I want to give you a broader view of what happens when all of this mid-decade redistricting collides with current trends in authoritarianism. In addition to the consequences for partisan power (which of course everyone cares about), these new acts of gerrymandering also imperil our ability to have a fair election at all.

Gerrymandering concentrates vulnerability

Most public analysis of mid-decade redistricting focuses on the horserace question of the net gain or loss in seats arising from the sum of all new gerrymandering. But the effects on power go well beyond that.

But even if Republican and Democratic gains come close to balancing out, as I have argued, they reduce the competitive playing field - and make it easier to interfere with a fair election.

Gerrymandering by either party reduces competition. Already, just because of geographic sorting, key Congressional elections will hinge on only a small subset of the 3,000 counties, the level at which elections are administered in the United States. Gerrymandering reduces that competition further, and I can imagine control of the House being determined by the vote count in just a few hundred counties.

Those few counties could easily be targets for interference: lawsuits that impede orderly vote-counting or vote-by-mail, or even incursions by military force. Imagine the National Guard or ICE being deployed to cities or places with large Hispanic populations. Cleverly targeted, that could swing critical races, such as the Texas 28th and 34th District, which are near the southern boarder and are over 50% Hispanic.

To see how this might play out, here are some key examples.

Attacking elections, state by state

When fewer districts are competitive, there are fewer places where getting out the vote matters. But 2026 is also headed toward being a year of increased efforts, by partisans and even government officials, to challenge existing voting rights.

Tools like Vote Maximizer will be important for showing citizens where votes are most powerful - and therefore likely to be attacked. In these places, it is critical to ensure the integrity of the vote, whether at polling stations or by making people feel that it is safe to get out the vote.

Three states are sites of a multi-seat gerrymander: Texas, California, and potentially Ohio. In all three states, a shared theme is is voter displacement. At the Electoral Innovation Lab, we anticipate that an average of one in four voters will be moved to a new district. This displacement of voters takes millions of voters out of their existing districts, and forces incumbents of both parties to learn about new constituents from scratch.

The good folks at The Downballot have come up with a helpful rundown of all conceivable states that may draw new Congressional maps mid-decade. They have taken an expansive view. Let me briefly review the ones with the highest likelihood of occurring and where we have a clear idea about the location of competitive districts. This can show us how those districts can come under attack, and what we can do to increase the likelihood of a fair election in 2026.

California: Riverside and San Diego Counties

California’s Proposition 50 goes before the voters in less than three weeks. It would enact a temporary congressional map, triggered by whether Texas Republicans pass a new gerrymander - which they did.

Many Democrats believe Proposition 50 to be their strongest defense against this year’s unprecedented wave of mid-decade redistricting. However, it paints a big target on several hundred thousand voters in Riverside and San Diego counties.

In our preliminary analysis, 22% of California voters statewide would be displaced into a new district. This disruption would lead to a gain of four or five seats for Democrats—close to a perfect offset of the Texas map. So in a sense, Californians are asked to give up some of their direct power over their representative, in exchange for an increased likelihood of partisan-fair outcome at a national level.

Current opinion surveys indicate that Proposition 50 is ahead by 15 to 20 points. It seems that this ship has sailed. Opponents of Proposition 50 are cutting their expenditures.

In 2024, nine Congressional races in California were decided by margins of 7 points or less. That is a large playing field, almost one-fifth of the nation’s such competitive districts. But Proposition 50 reduces those 9 competitive districts to 1 competitive district.

The proposed map in California has only one competitive district, the 48th. It’s 36% Hispanic, pretty much prime territory for federal interference via ICE.

Texas: Focus on border districts

In Texas, Republicans have targeted five seats. Three of these, in Dallas, Houston, and San Antonio/Austin, are likely to go in Republicans’ favor. The fourth and fifth seats, Districts 28 and 34, are still probably competitive. Sitting along the border with Mexico, they appear to have been drawn under the assumption that they will perform as Trump did in 2024, when he won more votes within the boundaries of the new districts. Since that time, Trump has lost considerable support in that demographic.

Under normal conditions, one could just ask whether incumbents Henry Cuellar and Vicente Gonzalez will run a good campaign. However, 2026 is unlikely to be a normal year. It is easy to imagine the deployment of ICE and Texas National Guardsmen to intimidate voters. It will be critical to protect the vote in these districts, whichever way they fall.

Ohio: Focus on Cleveland, Akron, and Lake Erie

In Ohio, a new map must be drawn because of that state’s specific legal processes. In conjunction with Leadership Now, the Electoral Innovation Lab has produced a report that outlines possible scenarios, as well as risks to incumbents and to the majority party. This report is freely available here:

From a partisan standpoint, redrawing the map may produce one or two additional seats for Republicans. However, in order to achieve that gain, at least 25% of Ohioans would need to be moved into a new district. These districts are likely to include key communities in the north: Cleveland, Toledo, and Akron. Vote security in those cities, and throughout the rest of northern Ohio, will be critical in 2026.

There is also the possibility of mitigating the partisanship of any new map. The new map may be enacted by the legislature or by the commission. Depending on where you live in Ohio, you have different ways to exert pressure.

• All voters, statewide: Contact Governor Mike DeWine. DeWine would sign a legislatively-passed plan, and is also on the redistricting commission. He will be involved no matter what. He might be persuaded to favor stability. Voters should ask to stay in their current district, saying that they would be confused or concerned with new representation.

• Residents of Ohio Congressional Districts 2, 7, 10, 14, and 15: These are Republican districts and are likely to be redrawn. Residents should write to their Congressman. Congressmen have no direct say in redistricting - but they will still have influence. In Republican districts, voters can contact Dave Taylor, Mike Turner, and Dave Joyce, saying how important it is for them to stay in their district. Ideally, these Congressmen will not want to see their districts redrawn because they see it as a headache with marginal gain.

• Residents of Ohio Congressional Districts 1, 3, 9, 11, and 13: These are Democratic districts. Voters who have a Republican state representative or senator should write to them, again to ask for stability.

Developing a tool to defend key elections

At the Electoral Innovation Lab, we are building on our tool from 2024, Vote Maximizer, to produce a resource to help defend elections. By identifying close districts, counties with vulnerable populations, and states with close statewide races, we will show you where you can make the most difference to protect fair elections. That tool will be ready for use by mid-2026.

Your donations will help us do that work. Your support will make it possible for the lab to translate its long-term efforts to produce practical tools to protect and strengthen democracy in 2026, when it will count the most.

And for those of you who work on using data for good: we are interested in information about county-level vulnerabilities: which counties have anti-vote-counting boards, ambiguous rules, and so on. If you’d like to be part of an effort, write to us.

I have bad news and good news for you on the gerrymandering wars.

The bad news is that more states are entering the fray: this week, Missouri, maybe Indiana, and mayyybe New Hampshire.

Now, the good news: The partisan gains are getting so small that now there's more heat than light. This creates a path to stemming the tide, which we are following at the Electoral Innovation Lab.

Despite the most recent expansion in the front of the war, the only multi-seat offenses are the same: three to five seats for Republicans in Texas, and a counter-gerrymander of five seats by Democrats in California. The latest poll indicates that California voters who are required to approve the gerrymander are strongly in favor.

It is a clear partisan offense to deprive Republicans of representation in California. But voters appear to see balancing the offense in Texas as an urgent goal - provided that California returns to a citizen-based commission in 2030.

As reported today in The Downballot, pressure is building on New Hampshire to redraw its two-district Congressional map. This is an object lesson in how desperate the maneuvers have become. The existing Second District went for Harris over Trump by 2. The best outcome for Republicans is to convert this to a district that favored Trump by 7 points - and even that requires drawing an incredible gyre. New Hampshire doesn’t have many strongly Republican or Democratic areas. Since a 7-point district can easily stay Democratic in the current climate, this is a lot of disruption to New Hampshire - for little or no gain.

The story is similar in other states. Offenses in Missouri and Indiana will deliver, at most, one district each, and maybe not even that.

And in Utah, legislators are fighting a state court case that restores the citizen commission’s power. As Dave Daley and I wrote regarding Utah, the gain is so paltry that legislators are better off letting citizens do the work.

Gerrymandering produces small drops against an incoming tide

Consider this: Republicans can only afford to lose three seats in 2026 - more than that, and they lose control of the House. Yet the median swing in a midterm election is 13 seats, and forecaster Elliott Morris now thinks a swing of 20 seats or more is likely. Against this incoming tide, moving one seat is just one small bucketful. As you can see in the table above, even a slew of impending offenses is unlikely to overcome that tide.

But it does remove competition - and that’s bad for democracy.

At the Electoral Innovation Lab, we are highlighting the smallness of these gains as a reason to stand down. In data-based analytics like our deeply-researched report on Ohio, we’ve measured the disruption that comes from moving voters out of districts. In our estimation, it typically requires moving 30% of voters to achieve an appreciable partisan gain. That's hard on both voters and incumbent legislators. And as our analysis of Ohio and Texas shows, many states under single-party control are maxed out. Trying to squeeze out more seats would mainly bring a risk of backfiring on partisans, what is called a "dummymander."

Appealing to legislators’ fears is not the most noble of arguments. But it is one that can work. At the Electoral Innovation Lab, we don’t just use data. Cognitive science shows that fear can be a more powerful motivator than reason.

Short-term mitigation, long-term solutions

In the long-term, a more uniform solution is needed, such as Congressional legislation to establish citizen redistricting commissions in every state. Our comprehensive research demonstrates the power of these commissions.

We will be continuing this work - as well as showing how citizens can maximize their power in every state in 2026, using tools like Vote Maximizer. With fewer competitive districts, this kind of short-term action can help maximize the odds that we will have fair elections in 2026 and in the tough years ahead.

Help support the Electoral Innovation Lab

You can help us in this goal by supporting our work. Protecting and repairing democracy is a big job. Please consider supporting the Electoral Innovation Lab. Help us fix gerrymandering and other major bugs in our democracy!

Here in Princeton, a new report from the Electoral Innovation Lab warns that Ohio’s upcoming congressional redistricting could displace millions of voters, destabilize incumbents, and further erode trust in democracy. But lawmakers have a chance to avoid this - and avoid an unnecessary gamble that may backfire on them.

The nonpartisan report, Ohio Mid-Decade Redistricting: A Nonpartisan Policy Analysis, analyzes the state’s redistricting process and models different scenarios lawmakers could pursue. National Republican, including Trump, want them to pursue an aggressive partisan gerrymander as a means of hanging on to power in 2026. However, it’s a gamble that could backfire if pursued too aggressively.

Ohio law has rules that keep counties and large municipalities whole. But millions of possible maps can still be drawn. Because of this, it is not possible to predict the exact form of the new map that will be drawn in 2025. But we can look at ways it might be done.

Working with the Lab, Perry Allen came up with this possible map:

This map (shown above with 2020 Presidential results) would move nearly 30% of Ohioans (about 3.5 million people) into new districts. It would carve up Toledo and Akron. Hypothetically, it could produce 11 to 13 Republican seats out of 15. Compared with the current 10-Republican contingent, that’s a gain of 1 to 3 seats.

However, past cycles show it could backfire: voting patterns in 2018 would produce as few as 7 Republican seats.

Because of the legal requirement to keep Cincinnati, Cleveland, and nearly all counties whole, drawing a map this aggressive would not just endanger Democratic incumbents, a partisan goal. It would also push several Republican incumbents out of their home districts, and make their re-election harder.

Alternatives take fewer seats and disrupt fewer voters

We’ve also gamed out some less-aggressive alternatives. For example, a map that left Cincinnati and southern Ohio alone would displace only 8% of voters. It would focus mostly on northern Ohio.

This would be more like 10 Republican, 3 competitive, and 2 Democratic seats. It could still produce one or two seats for Republicans, but be less likely to backfire.

Reminder: a fair map is possible

Finally, the Lab reminds everyone that a fair map is possible. Here’s a plan that produces 8 Republican, 4 competitive, and 3 Democratic seats. It mirrors Ohio’s actual statewide partisan balance (56% R / 44% D), respects county and community boundaries - and isn’t a partisan gerrymander.

Such an outcome could only arise from a binding independent citizens’ commission. Such an initiative failed in 2024. But a ballot-initiative route may yet succeed in future years, especially as gerrymandering enters the national spotlight.

About the Electoral Innovation Lab

The Electoral Innovation Lab, based here in Princeton, New Jersey, uses data science and statistical modeling to help repair and preserve democracy. Please support us!

To understand what we've done, first it's important to dispel the single most common misconception about redistricting: the myth of proportionality.

Most non-proportional results aren't gerrymanders

Over and over, I encounter statements like this: "Massachusetts votes 60% Democratic, yet nine out of nine of its representatives are Democrats. Surely that's a gerrymander."

Actually, no, it's not.

The simple reason is that no district-based system guarantees proportional representation. And it's not because of purposeful manipulation by bad actors. Even a neutral, non-partisan process will lead to a non-linear translation of votes into seats.

In the example of Massachusetts, Moon Duchin and collaborators demonstrated in 2019 that Republicans are distributed so evenly around that state that it was mathematically impossible to draw a majority-Republican district. This shows that distribution matters. To see how general this idea is, graphs can help.

Understanding the Math Behind District-Based Systems

First, let's think about single districts. Imagine that a political party gets 60% of the vote in a district. They therefore elect 100% of a member of Congress. Such a method is not unfair or gerrymandered. Rather, there is no other way to assign a single seat.

So the number of seats as a function of votes looks like this:

For obvious reasons, this is called a step function!

Now imagine a state with just two districts (for example, Idaho or New Hampshire). If one is a little above average for the state, the other has to be below average by the same amount. Now representation depends on statewide average vote like this:

In this case, I have added a red diagonal line to show what proportionality would look like. But as you can see, whole ranges of vote (in this example, 0 to 42%, 58 to 100%) lead to both seats going to the same party.

However, this is not necessarily because of nefarious intent. In a 50-50 state, a 58% Republican, 42% Democratic district and a 58% Democratic, 42% Republican district don’t sound that crazy. This could happen just because of where people choose to live.

For example, Idaho is all the way to the right of the graph for Republicans, and has two representatives of the same party. That’s not because Idaho is gerrymandered. Idaho is just really Republican.

The S-Curve: Why multi-district systems create non-proportional results

To understand a larger state like North Carolina or Pennsylvania, we can keep going by adding more districts that are distributed around the statewide average vote. When we have lots of districts, the relationship between votes and seats typically looks like an S-shaped curve:

Oh dear…from a proportionality standpoint, this is not going well at all! But it is exactly what arises from a realistic, neutral process. Why is that?

The reason for the S-shape is that districts' voting tendencies fall on a bell-shaped curve. The number of seats you get as a function of the average vote is then the area under this curve, which is shaped like an S. (Many years ago, political scientists called one version of this curve the cube law, for reasons I will skip today.)

As it turns out, this is what neutral districting processes do - they make districts whose partisanship tends to follow a bell-shaped curve. That’s because districting has to follow lots of rules and has to represent cities, counties, communities, and racial groups. When all of those conditions are met, then partisanship is an incidental output of the system - and according to the laws of statistics, follows a bell-shaped curve. The exact shape of this curve depends on how variable districts are, and sometimes it is a little skewed, for reasons like geography.

However, the seats-votes curve can be distorted if the redistricting process places partisan advantage above other criteria - in other words, if a partisan gerrymander is committed.

Using math to identify a gerrymander

When a state has a seats-to-votes relationship that deviates from this S-shaped curve statistically, there has to have been some other reason. One possibility is that people live unevenly—for instance, Democrats living in cities and Republicans living in rural areas. In practice, that leads to only small discrepancies. Such effects are much smaller than those of purposeful gerrymandering.

The Princeton Gerrymandering Project has developed ways of incorporating this kind of statistical thinking into its grading system. The Gerrymandering Project calculates what would be a fair range of seats based on statewide vote. It also does hundreds of thousands of simulations in each state that start from the actual voting patterns, thus estimating what a neutral process would produce, given a state’s particular political geography.

All of this gets used as part of a comprehensive grading rubric. The resulting grading system can be applied to any state legislature or congressional delegation. Grades range from A to F. Roughly speaking, A and B are good grades, while C, D, and F are bad grades. Just like real life, but without grade inflation.

The Princeton Gerrymandering Project - Congressional Report Card

At last, here are current grades for all states with more than one House district.

We’ve paid the most attention to the 2021 cycle of redistricting. But these standards are timeless: the S-curve-based approach can identify gerrymanders of the past as well.

Here is a timeline of gerrymanders by decade. This bar graph shows the number of states where one party controlled Congressional redistricting, and gained two or more “excess seats” as a result, which almost always gets an “F”.

This was the basis for last week’s list of Top 10 Gerrymanders.

The power of independent citizen redistricting

That report card (and another one, for legislative maps) allowed us to inspect each state. We could then do something important from a policy standpoint: we could evaluate which redistricting systems led to the fairest outcomes.

Working at the Electoral Innovation Lab, Zachariah Sippy did something heroic: he analyzed the redistricting rules in all 50 states. Every state's rules are slightly different. We then noticed a very interesting pattern.

This histogram shows the grades that arise from partisan mechanisms on the one hand (legislatures, politician-appointed commissions), and nonpartisan mechanisms (independent citizen commissions, courts, advisory commissions) on the other hand. The results are quite different.

Basically, anytime an independent commission or a court is in charge of drawing lines, then the PGP grading rubric gave it a grade of A or B. In no case was the grade C, D, or F.

On the other hand, partisan processes produced more variable grades. With disturbing frequency, the grade was a D or F. Those are instances where the number of seats deviated strongly from neutral expectations.

From this systematic comparison across every state, we learned that there is a very particular way that districting can be fair: take the power away from legislators. Whether by commission or court, application of rules and principles by people who have no direct stake in the game leads to an outcome that resembles a neutral process.

The Competition Factor

Another interesting feature is competition. We see very different patterns of levels of partisan fairness depending on the rule for redistricting. The amount of competition is also quite different.

The fraction of competitive districts—defined as races that we estimate to be within seven points or less—is much lower in politically drawn maps than in maps drawn by commissions and courts.

The effect is even more apparent for legislative maps.

This is perhaps not surprising. Legislators want to reduce risk for themselves individually. They can reduce risk for their opponents as well, and can even sometimes get a bipartisan vote for their plan. That’s called a bipartisan gerrymander. And independent commissions and courts don’t do it.

The Path Forward

In conclusion, despite the controversies we've been seeing, there is a clear formula for how to get better districting. In about half the states, citizens have the ability to amend the constitution and form an independent redistricting commission. In some states like Illinois, extreme gerrymanders can be prevented in this way.

Such a route is not available in states like Texas, where no laws govern congressional redistricting whatsoever—truly, Texas is the Wild West. The only way Texas will ever get better districting is through federal law. Until then, the only justice is rough justice - which is why California is attempting to balance the offense with an equally-sized counteroffense.

Support the Electoral Innovation Lab!

If you liked this analysis, be aware that it was made possible by both the Princeton Gerrymandering Project and the efforts of the Electoral Innovation Lab. The Electoral Innovation Lab is a nonprofit, independent organization. It needs your support!

Acknowledgements: This work built on the efforts of the Princeton Gerrymandering Project, in particular Hannah Wheelen, Ari Goldbloom-Helzner, Ethan Arsht, and Drew Curran; and the Electoral Innovation Lab’s Zachariah Sippy and Setu Loomba. Thanks to them and many more partners!

We chose 50 years as the time scale because in 1972, legislatures had to start drawing Congressional districts to be of equal population, thanks to the 1964 Supreme Court ruling (Reynolds v. Sims) mandating the "one person, one vote" principle. (Legislative districts also have to be of equal population to one another, but we're not analyzing those here.)

To make a clear comparison, we've focused on metrics based on statewide vote share. This is similar to what I did in my original 2013 piece on the Great Gerrymander of 2012, my 2016 Stanford Law Review article on three tests for gerrymandering. Statewide tests also form a major component of the Princeton Gerrymandering Project report card. In all cases, the concept is that it’s possible to estimate how many “extra” seats come from partisan line-drawing, above and beyond what neutral principles would produce.

It's important to note that this measure does not capture everything. It doesn’t explicitly take into account the political geography of where voters live. However, those effects tend to be rather small. If you look at the Princeton Gerrymandering Project, the “fair range” based on statewide vote and computer simulation overlap, leading to similar results for current maps, as you can see over at PGP.

A second factor we’re leaving out today is the Voting Rights Act. Currently, the VRA requires fair representation of Black, Hispanic, and Asian communities. Drawing maps to comply with these requirements can often lead to representation that deviates from what a vote-share-based analysis would produce. Generally, consideration of race tends to bring a plan closer to proportional representation. We decided to leave out consideration of the VRA. However, by the end of this article, you will see what happens when it is disregarded.

Finally, we've left out a number of plans that were drawn by state courts. State courts usually draw maps that are pretty balanced between the two parties. When they deviate, it is often because of VRA requirements or other factors. Because of the complexity of court cases, we have left them out of our analysis.

We will soon be issuing a full report on these findings (mathematical methods are here).

In the meantime, without further ado…here are the top 10 worst partisan gerrymanders of modern times.

#10, #9, and #8: Florida, Michigan, and Virginia - 2 seats each, multiple decades

These three states are multiple offenders. Over and over again, the legislative majority carved out two additional seats compared with what a neutral process would produce. But it wasn't always the same party doing the carving.

In Florida, Republicans have succeeded in getting two extra seats for themselves twice: first in 2002 and again in 2012. But they were not the only ones to do this—Democrats also did it back in 1972 when they dominated state politics.

Interestingly, the current Florida Congressional map does not look as extreme as those old gerrymanders. The reason is that Florida has been trending Republican, voting 58% Republican, 42% Democratic in 2024. Under those conditions, a delegation of 20 Republicans and 8 Democrats can arise naturally.

In Michigan, the story is simpler. Republicans controlled redistricting in 2002 and 2012, and in both cases carved out two additional seats for themselves. However, the Michigan gerrymander of 2012 was not done as artfully as it could have been. After several cycles, it eventually failed as voting patterns around the state shifted. By 2018, the Michigan gerrymander had given way to a more equitable distribution of seats. In some sense, this could be considered a "dummy-mander" because it did not hold for the entire decade.

Finally, we have Virginia, whose Republican-controlled legislature drew a gerrymander that gave them two additional seats in 2012. Both Democrats and Republicans did this in previous decades. But the 2012 Virginia gerrymander is special because it triggered positive reform. After Republicans drew the congressional map, they realized to their consternation that they might lose partisan control of government to Democrats due to demographic shifts. They therefore had a "come to Jesus" moment in which they developed an interest in nonpartisan redistricting.

A combination of citizen and bipartisan political efforts led to the establishment of a commission that partially took the power of redistricting away from the legislature. This commission is composed of both citizens and legislators. It's not perfect—in 2021 it deadlocked and threw the whole process into the Virginia Supreme Court. But that court did a bang-up job of drawing a fair map, appointing special masters Bernie Grofman and Sean Trende, nominated by Democrats and Republicans respectively. They drew a remarkably balanced map that, in our estimation, has no bias in either direction.

To read more about Virginia’s remarkable move toward fair districting, read this account by the Lab’s Zachariah Sippy and me.

#7, #6, #5, and #4: North Carolina (R), Ohio (R), California (D), and Illinois (D) - 3 seats each

The difficulty with reviewing 50 years of gerrymanders is that inevitably there are multiple specimens. In this category we have four distinguished winners, two drawn by Republicans and two by Democrats.

Two gerrymanders in this category were part of the Great Gerrymander of 2012. In 2012, Republicans gained control over redistricting in half a dozen legislatures. Because of that, and because of the increasing separation between the parties since the mid-1990s, they were motivated to draw an amazing array of gerrymanders. It was a high-water mark, leading to a net 20-seat advantage for Republicans. Before and after that, the advantage has never been more than 9 seats for either party.

The two Republican gerrymanders in this category were in North Carolina and Ohio. In North Carolina, the governor lacks a veto, so the legislature was left to its own devices. They drew a map that turned a 50%-50% statewide vote into a 10 Republican, 3 Democrat delegation. Ohio Republicans drew an equally extreme map. See my deep dive here.

The more famous Democratic offense took place in 1982, when political boss Phil Burton directed what at the time was considered an egregious offense: squeezing out multiple additional seats for Democrats. It is cited to this day as an example of Democratic overreach. This gerrymander was infamous because it came just 10 years after the introduction of the "one person, one vote" standard. Using our methods, it was a net three-seat gain for Democrats.

A similar offense is in place today. It was drawn by Illinois Democrats, whose current Congressional map elects 14 Democrats and 3 Republicans. By our calculations, a more natural breakdown in Illinois would be 11 Democrats to 6 Republicans. This map gets an “F” from the Princeton Gerrymandering Project.

#3 and #2: Pennsylvania and Texas - 4 seats each

Until recently, the worst gerrymanders in modern history were able to squeeze out four seats for a party. That takes a large state, so it’s no surprise that these took place in Pennsylvania and Texas.

Pennsylvania’s 2012 map was part of the Great Gerrymander of 2012. In Pennsylvania, redistricting is done by the legislature and governor, and Republicans made full use of their single-party control. The resulting map elected 13 Republicans and 5 Democrats, which is pretty extreme in a state that routinely votes 50%-50%. By our metrics, this counts as a four-seat advantage.

Pennsylvania’s gerrymander will not be repeated, for two reasons. First, the state Supreme Court ruled that partisan gerrymandering violates the state constitution. As Ben Williams, Rick Ober, and I have reviewed, every state’s constitution has provisions that can be used for this purpose: requirements supporting freedom of association, equal justice under law, and free and fair elections. A few states have made use of those provisions.

The other gerrymander in this category was drawn by Democrats in Texas in 1992. This was, in some ways, the peak of Democratic influence over Texas redistricting.

Both Pennsylvania and Texas represent peak gerrymandering efforts by their respective parties, each managing to extract significant partisan advantage through sophisticated map manipulation.

#1: The Texas Gerrymander of 2025 - up to 7 seats

Consistent with the enormous fuss that's been expended over the last month, the new Texas congressional map is indeed the worst gerrymander of the last 50 years. It's going to net Republicans an advantage of 3 to 5 seats. That’s on top of an already extreme partisan gerrymander that they enacted in 2021. The grand total is 5 to 7 additional seats above what a neutral process would produce.

This is simply phenomenal. It outstrips all other gerrymanders, including a variety of Republican offenses in 2012, as well as the 1982 Democratic offense in California and the current map in Illinois. The Texas gerrymander of 2025 stands alone as the most extreme manipulation of electoral boundaries in modern American history.

Now, how is it that Texas has been able to achieve such a dubious honor? The answer is simple: they are disregarding the Voting Rights Act. By ignoring the representational needs of Black and Hispanic populations, including coalition districts, they are able to eliminate districts in Dallas, Houston, and San Antonio. And if they get lucky in 2026, they may be able to eliminate two Hispanic-represented districts at the southern border that are currently held by Henry Cuellar and Vicente Gonzalez.

If this map stands, it will be because the Supreme Court is ready to discard what is left of the Voting Rights Act. And Texas’s record will enter the history books.

(Dis)honorable mention: The California draft plan, 5 seats

California’s draft plan, unveiled this week, is nearly as bad as Texas’s. Based on the same methods as those used above, the new plan adds an average of 4 Democratic seats above the current plan, which already has a 1-seat advantage. That leads to a total of a 5-seat advantage. This advantage is at the bottom of the range of what the new Texas plan will do.

If California voters pass it this November, which is a requirement of the constitutional process there, their state will join Texas as producing one of the two worst gerrymanders of the last 50 years

Note: In our analysis, we are leaving out a few other large deviations which appear to arise from vagaries of population patterns and the Voting Rights Act, including the 1982 Texas congressional map (which was drawn by a court) a map drawn under bipartisan control in Ohio in 1972, and a map drawn by the California Supreme Court in 1992. Other two-seat gerrymanders that fell by the wayside in our estimation include offenses in New Jersey, New York, and Wisconsin. There’s much more to say about these smaller offenses, but not today.

Greetings from Cape Cod! Doing radio and TV today, which seems to work from here. Earlier this week (Monday) I was on the PBS News Hour (starts at the 33:40 mark).

Today, more on gerrymandering. Scheduled tentatively, all times Eastern:

• BBC World Service radio, around 3:20pm and 4:20pm. [recording]

• The Day on PBS America (and Deutsche Welle TV), 4:40pm [episode] [interview[

• BBC News - The Context USA, at 6:30pm

What I’ll talk about:

The Electoral Innovation Lab, which is building a science of voter power, has analytics showing that the Texas redistricting plan is the most extreme gerrymander in 50 years. Since 1972, the first year that districts had to be of equal population (“one person, one vote”), no plan has been as extreme as what’s under consideration by Texas Republicans.

However, California’s counterproposal will be just as extreme in the other direction, favoring Democrats. We’re working on a report on these record-setting offenses, and will release it soon.

After all that, back to this soon I hope…

I propose that any response should be measured and proportionate. In other words, if there’s going to be a response, it should be limited to the size of the Republican offense. Today I estimate the size of the offense in different states and identify proportionate actions.

There are two reasons for putting limits on action:

1. Democrats currently claim the high ground as the party of making government represent all the people. Going back on that commitment undermines the concept of a responsive, well-working democracy.

2. Democrats have only one clean option for a retaliatory strike: California. Additional options will yield little to no benefit.

The Texas gerrymander is only likely to yield 3 additional seats. Ohio will only add 2 or 3 seats. These offenses are manageable.

What advocates say in favor of tit-for-tat action

First, what is the best argument for considering tit-for-tat action?

Congressional power is determined by the sum of elections in all fifty states. Despite this, each state has its own rules for redistricting. The Supreme Court will not act to restrain partisan gerrymandering, and it keeps on undermining existing federal protections such as the Voting Rights Act. As a result, fair districting is subject only to the laws of individual states. Therefore, having a representative national assembly is subject to the caprice of individual states.

As a worst-case scenario, consider the Great Gerrymander of 2012. As I wrote back when it happened, Republicans had a net advantage of nearly 20 seats. That is the worst advantage in the age of modern voting rights (rights that peaked and are slowly ebbing, thanks to the Roberts Supreme Court).

In plans drawn up in 2022, the Republican advantage is much smaller, about 6 seats. (You can browse all offenses, Republican or Democratic, at the Princeton Gerrymandering Project.)

Now, President Donald Trump wants Republican legislatures in Texas, Ohio, Florida, Indiana, Missouri, and New Hampshire to perform mid-decade redistricting. If all of them complied, it would produce an advantage of about 10 seats on top of the 6 seats I mentioned before. That gets us close to 2012 conditions.

For this reason, an argument can be made for each step taken to benefit Republicans, Democrats should take a countermeasure. In a deep sense, that might be called fair.

The best first step is to reduce gerrymandering. In that respect, blocking the new offenses would be the best move. Texas Democratic legislators are attempting just that. They are fleeing the state and denying quorum, one of the few procedural steps available to them. Based on past history, success is not at all assured, but then again, they’ve never had national attention and presumably, considerable material support.

Assuming that fails, if we are going to go down this road, then it becomes important to actually count seats. By that measure, the realistic current multiseat threats are in Texas, Ohio, and California.

Burning down the House line-drawing process

What states are in a position to redistrict mid-decade? I took a preliminary stab at that question here. What would across-the-board mutual escalation look like?

Here is a table of achievable new gains from mid-decade redistricting.

I constructed this table from two kinds of information. First, working with the Electoral Innovation Lab, Yusuf Arifin has surveyed the laws of all fifty states to identify whether a mid-decade redraw is currently allowed. I have omitted states that forbid it, including states such as Colorado and New York where it would take several years to change the state constitution. I have also left out states whose courts have already limited partisan gerrymandering, in particular Maryland, and again New York.

Second, I estimated the net gain that would realistically arise from drawing a new gerrymander. This was done using analytic approaches developed here, augmented in some cases by the legions of hobbyists who use Dave’s Redistricting App.

Example: Texas’ new plan may produce only three seats

Texas Republicans have attempted to draw five additional seats for themselves. In 2021 they restrained themselves, in part to forestall a voting rights challenge in federal court. But with a U.S. Department of Justice that is now opposed to racial voting rights, they are trying again.

There are good reasons to suppose that their new map might not work out as they have planned. The effectiveness of their handiwork rests on three assumptions:

1. Support for Republicans in 2026 will match support for Trump in 2024.

2. Trump’s gains in 2024 will be matched downticket in Congressional races.

3. Latino voters will both maintain their recent swing toward Trump and maintain off-year turnout.

There are problems with all three of these assumptions.

Mid-term swing. Republicans will almost certainly lose support in 2026. This is why they are desperate to redistrict.

In dozens of special elections this year, the median D-minus-R swing is 13 points compared with the 2024 Presidential vote. This overperformance has a track record of predicting the swing in the next Congressional election. Texas Republicans have built in 10-point margins based on Trump-versus-Harris 2024 election results, but it might not be enough.

Short coattails. Trump made major inroads in Texas, especially in Hispanic and border communities. But even in 2024, Democratic congressmen were able to win in districts where Trump got more votes than Harris. In particular, pro-Democratic margins were 13 points better for Rep. Henry Cuellar (CD28) and 7 points better for Rep. Vicente Gonzalez (CD34). Those candidates have some special connection to their border communities. This will still help them in 2026.

Latino letdown. Hispanic voters swung toward Trump by 22 points in 2024 compared to 2020. I estimate that nearly half of that swing has reversed; Hispanic approval for Trump is now only 35% nationally. I don’t know where that will end up, but I also note that Hispanic turnout tends to be poor in midterm elections.

Democrats’ few options

There are very few paths for Democrats to pursue. For example, Maryland and New York courts have already limited partisan gerrymandering. In New York, mid-decade redistricting is additionally prevented by Article 3, Section 4 of the New York Constitution. In those states, there is no easy path to draw new gerrymanders.

If Democrats insist on committing this offense, there is only one state that will make a substantial difference: California.

California's redistricting is currently done by an independent redistricting commission. Overriding that commission would require a change in the state constitution. Governor Gavin Newsom is considering bringing such an amendment to the voters in a special election this fall. The Legislature would have to pass the amendment by a two-thirds vote, and it would go before voters on November 4.

If the law changes, it would be possible to add five safely Democratic seats to California's delegation. Such a map would be enough to counteract the combined effect of new gerrymanders in Texas (3 seats) and Ohio (2 seats).

In some ways, California offers the least reputational risk to Democrats. They have faced claims that the state is already gerrymandered, since it’s currently 43 Democrats to 9 Republicans. That is untrue: the pattern arises simply because of the natural geography of the state. With a mid-decade redraw, critics can find out what an actual gerrymander looks like.

Any change should be temporary. California’s commission process has been highly successful and presents a model of how a fair process ought to work. It draws reasonably fair Congressional and legislative maps. Its Congressional map got a grade of B from the Princeton Gerrymandering Project (which is a good grade; California’s geography makes an A impossible under the PGP rubric). Good government, and doing the least damage to democracy, requires reinstating that system in 2031.

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Digging coins out of the couch

After California, Texas, and Ohio, there are fewer coins to be scraped out of the couch by either party. The next tranche is unpromising: Missouri, New Hampshire, and New Jersey.

To redraw its map, Missouri would have to overcome resistance within the Republican caucus, but could make its 5th District Republican.

In New Hampshire, Democratic and Republican voters are interspersed throughout the state. Drawing even a competitive but Republican-leaning district is nearly impossible, and would require something like this:

New Jersey currently uses an independent redistricting commission*. Changing that would require bringing a constitutional amendment to voters in 2025. That process would have to start immediately.

The current map in New Jersey has 8 Democratic districts, 3 Republican districts and 1 swing district, and is approximately what would arise from a neutral line-drawing process. Drawing a gerrymander might convert a Republican district in south Jersey. That one-seat gain does not seem like enough to justify discarding a decades-old reform.

Keep it in California

At a troubled time for US democracy, it is understandable that people may be in a panic over next year's congressional election. Three seats would be enough to change control of Congress, and the median change in a midterm election is 13 seats. Generally, one would want any distortions from mid-decade gerrymandering to be smaller than that.

Any action to blunt the effects of mid-decade redistricting should be done with an eye to the actual benefit. Everywhere but California, the benefits are pretty small.

*Disclosure: the Princeton Gerrymandering Project was the technical consultant for the New Jersey redistricting commission.

Thanks to Yusuf Arifin for legal research.

As of today, it looks like a little of both.

Texas Republican legislators have posted their first draft Congressional map. We can start to see (a) what they are gambling on, (b) how much they think they can gain, and (c) how much downside risk they are taking.

The draft map, presented by state Representative Todd Hunter (R), has the potential to bring Republicans 3 additional seats on top of their current gerrymandered map of 25 Republicans, 13 Democrats. That three-seat gain is close to what I suggested was the most they could hope for. For a state that voted 56% Trump, 42% Harris in 2024, at first blush that is an impressive feat of line-drawing.

However, this map could still backfire by nearly as many seats: under it, Republicans could also lose 2 seats.

One out of three Texans: Welcome to your new district!

Finally, this map moves nearly one-third of Texans into a new district. Based on 2020 Census data, 32% of people would be separated from the district they are in now. The need to woo unfamiliar voters, especially with more competition, will make a lot of work for Congressional candidates, especially Republican incumbents. It seems likely that running under this map will require tens of millions of dollars of increased campaign spending, compared to keeping the current map.

Betting that 2026 will be like 2024

The map appears to have been drawn under the assumption that Texans will vote like they did in 2024. You can tell because every district’s 2024 Presidential margin is more than 10 points.

Compare it with the distribution of 2024 Presidential vote under the current map:

However, 2024 was a high-water mark for Republicans. If that support ebbs significantly in 2026, especially among Hispanic communities, Republicans could win as few as 23 seats, two seats less than they have now. They are increasing their risk in the hopes of increased return.

In south Texas, the new draft map contains some aggressive moves. Five border districts, 23, 28, 34, 35, and now District 15 (which used to be a funny-looking district between San Antonio and Austin), have all been redrawn to reflect Trump's gains in this region. Two of the border districts were already competitive in their 2024 form, and are represented by Democrats Henry Cuellar (CD28) and Vicente Gonzalez (CD34). In Representative Hunter’s map, they would still be competitive; I think Republicans could well lose these, even in the new plan.

Consistent with what I wrote in The Texas Jigsaw Massacre, Republicans are looking for new districts in greater Houston (CD9) and Dallas-Fort Worth (CD32). Actually, I cannot really say where CD32 is, since it stretches most of the way to Louisiana.

If these Hispanic-rich districts swing back, the map becomes a "dummymander" - a gerrymander that backfires on its maker. In an election that is more like 2020, which is an 8-point swing from 2024 conditions, most of these will become winnable by Democrats:

The Senate 2018 results, in which Beto O’Rourke (D) came within 2.5 percentage points of Senator Ted Cruz (R), are on average an 11-point swing from 2024. Because of larger swings in south Texas, this map is even clearer in showing just how swingable border Hispanic communities are:

When you consider the distinct possibility that the 2026 election might go hard against Republicans, this can easily turn into a map that elects 23 Republicans, 15 Democrats - a loss of two seats. That’s probably not what its drafters had in mind.

In my estimation, this map has up to 7 ostensibly Republican districts with Congressional margins that could easily be less than 10 points: CD 9, 15, 23, 28, 32, 34, and 35. At least two of them (CD28 and CD34) could easily go Democratic in 2026.

Everything’s bigger in Texas

Overall, I would characterize this as a draft plan driven equally by ambition and by desperation. The ceiling performance for Republicans is higher - but it also provides more opportunities for Democrats. In short, my impression is that it doesn’t live up to the existential threat to fair elections in 2026 that we’ve been reading about.

But, the legislature does get to keep trying. To be continued…

If you like this kind of analysis, please consider supporting the Electoral Innovation Lab. The Lab uses data and science to understand the kind of distortions that currently occur in U.S. democracy. By analyzing gerrymandering and its solutions, the Lab is working to bring about fairer districting in Congress and legislatures all over the nation.

Early this morning I joined Kim Brunhuber on CNN International to talk about the latest attack on U.S. democracy: mid-decade redistricting.

I made it sound simple: most of the opportunities for malfeasance belong to Republicans, but the effect might not be large enough to make a difference in the 2026 election. Therefore Democrats shouldn’t engage in tit-for-tat with their own gerrymanders.

However, it’s not that easy. Here at Fixing Bugs In Democracy, let me divide the question into two parts:

1. Will any consequences be large enough to affect who controls Congress in 2027?

2. What should Republicans and Democrats do now? Is the outcome worth the effort? To what extent should they be willing to tear up laws, norms, and existing reforms?

Today I will address point #1, and save point #2 for a later post. One big reason is that the answer to #2 depends on the answer to #1. If the question is whether to fight fire with fire, is the benefit worth the risk of burning everything down?

Desperation Time

In the modern age of voting rights, redistricting is almost always done only in the year following the census, i.e. 2011, 2021, 2031… Doing so once per decade is necessary in order to maintain equal population between Congressional or legislative districts within a state.

However, the Supreme Court’s growing hostility to voting rights means it’s open season on such norms.

Republicans in Congress only won a 5-seat majority in 2024. This is an incredibly small margin, the smallest since 1930. Shifting just 3 districts in 2026 would be enough to give control to Democrats. Which means that in 2026, the smallest change in public opinion (indeed, even unusual weather on election day) might be enough.

Now add two more facts. (a) National politics has gotten ever more polarized and extreme since the mid-1990s; and (b) during that time the median change in seats in an election has been 13 seats.

And 13 is a lot more than 3.

In ten of the twelve elections in non-redistricting years, the change has been 3 or more seats. So even if no new redistricting takes place at all, Republicans are in trouble. And with the extreme changes in our system of government happening with single-party control, a change in partisan control of one chamber of Congress would be an extremely big deal.

Tearing the couch apart for loose change

In 2022, I estimated the net result of redistricting as a 6-seat advantage for Republicans compared with neutral map-drawing processes. This was a considerably more balanced overall outcome than previous decades, especially compared with 2012. There are more competitive Congressional and legislative elections, thanks to commissions and courts (see our 50-state review). Might this positive trajectory be reversed?

Redistricting in the middle of the decade is a move born of desperation. Indeed, both parties may be under exceptional pressure to eke out the smallest gains. The goal, to make (or avoid) a net change of three seats, is the equivalent of loose change.

However, desperation can lead to stupid moves. As I wrote about Texas, excessively aggressive redistricting can backfire.

The prime targets for mid-decade redistricting are states under single-party control. These states are typically already gerrymandered, but the map could either be even more aggressive, or accidentally helped the other party, a “dummymander.”

Texas and Florida

For Republicans, the largest gains may occur in Texas and Florida. Certain things stand in the way, Section 2 of the Voting Rights Act for example. Also, getting too greedy.

As I wrote last week, pursuing Trump's goal of gaining five congressional seats in Texas is probably not a great move. It would require some exceptionally contorted shapes and displace up to a dozen sitting Republican congressmen. And the resulting margins might not withstand a Democratic wave in 2026.

But the Texas legislature could manage to make smaller gains. Compared with the current gerrymander, which gets them 25 out of 38 Republican seats, Texas could possibly extract up to 3 additional Republican seats. This would require eliminating districts where Hispanic populations have the ability to elect members of their choosing. With a Department of Justice and a Supreme Court is keen to erode race-based voting rights, they can probably get away with this - and also effectively end Section 2 of the Voting Rights Act.

A similar story emerges in Florida. Currently, the Florida congressional delegation comprises 20 Republicans and 8 Democrats. This map is already aggressively gerrymandered. Governor DeSantis may be tempted to use Trump’s 13-point win in 2024, powered by Hispanic voters in south Florida, to guide the preparation of an even more aggressive map. But like Texas, an excessively aggressive strategy might backfire: in a near-tie vote under the current map, Republicans would lose 3 of their 20 seats. Keeping in mind that the goal is to protect against a Democratic wave in 2026, the best hope of a new map would be to avoid those losses. However, an upside gain of up to two or three Republican seats is possible.

Potential gains from new maps: in Texas, 3 added Republican seats; in Florida, 2 added Republican seats.

Ohio

Under the complex rules of Ohio redistricting, any plan passed on a purely partisan basis, as was the case in 2021, can only be used for four years. Ohio is therefore required to draw a new map this year.

Ohio’s current Congressional plan has backfired on Republicans. It appears to have been intended as an aggressive gerrymander which could have produced as many as 13 Republican seats out of 15. But Democrats did unusually well in 2022 and 2024, and held Republicans to only 10 seats.

The legislature or redistricting commission—in both cases dominated by Republicans—will likely want a safer gerrymander. They still have to follow Ohio law, which does things like force Cincinnati to be kept whole within a single district. The new plan might safely be able to deliver one or two more seats, ending up with up to 12 Republican seats in total.

(It should be noted that Ohio Democrats have mechanisms to prevent this from happening.)

Potential gains from new maps in Ohio: 2 added Republican seats.

Other Republican opportunities are slim

Of the potential targets listed in a report by Punchbowl, Republicans might potentially be able to gain a seat each in Missouri and New Hampshire. These would require a change of heart by Republicans in New Hampshire, and may be against the law in Missouri. It is likely that the success or failure of efforts in Texas, Florida, and Ohio will play a role in whether they decide to disrupt their politics in the middle of the decade.

Other states (Indiana, Kansas, Kentucky, Nebraska) seem unlikely to participate in this mid-decade festival.

Potential Republican gains from other states: none, yet.

Democratic Party options are limited

Democrats have considerably fewer options. In many cases, even where they control redistricting, they have already enacted the most extreme possible maps: Illinois (14 D, 3 R), Oregon (5 D, 1 R), and Maryland (7 D, 1 R).

Other states have taken the redistricting power away from politicians. For example, New Jersey uses an independent commission (disclosure: I worked for it). However, it is too late for them to begin the process for abolishing it, which would require amending the state constitution. Anyway, the swing Republican district there is already at risk, and could probably be won without redrawing the map.

California is the one place where independent redistricting might be abolished in time: Governor Newsom does have the power to refer a constitutional referendum to voters. However, an independent commission, using the natural geography pattern of California's voters, has produced a map that already elects 49 Democrats and 9 Republicans. A few more seats could possibly be squeezed out. However, this requires Newsom to get voters to repeal or temporarily suspend the state’s process. That process, developed over the last few decades, specifies a citizen-based, politician-free process for drawing Congressional and legislative maps.

Potential Democratic gain in California: 3-5 seats*.

Utah

It does not count as mid-decade redistricting, but it should be noted that the Utah Supreme Court is considering a case that might restore power to the citizen redistricting commission. This would undo the current gerrymander, in which greater Salt Lake City has been divided into pieces. If that is overturned, Democrats would gain a seat.

Potential Democratic gain in Utah: 1 seat.

*DRA fanatics, weigh in please.

Summary

For the time being, mid-decade redistricting would net Republicans a total of up to 7 additional seats in Texas,Ohio, and Florida. Democrats might possibly gain 6 seats in California (in response to Republican actions) and Utah. The total net change compared with current conditions would hypothetically be between 1 and 7 Republican seats.

The median swing next year expected from historical patterns is 13 seats. So while mid-decade redistricting may give Republicans a small advantage, it seems unlikely that it will be the determining factor in control of Congress.

If you like this kind of analysis, please consider supporting the Electoral Innovation Lab. The Lab uses data and science to understand the kind of distortions that currently occur in U.S. democracy. By analyzing gerrymandering and its solutions, the Lab is working to bring about fairer districting in Congress and legislatures all over the nation.

Republicans, desperate to retain control of Congress after the 2026 election, are looking for ways to get more seats out of the national map. Generally speaking, midterm elections tend to go against the party of the president in power. Since 2004, the U.S. House has changed by a median of 13 seats in non-redistricting years, far more than the four seats currently needed to change partisan control, and far more than the benefits of any new redistricting plan in Texas.

The worst-case scenario for Republicans arises from the fact that they are currently unusually unpopular. In special elections, Democrats have overperformed their 2024 margins by 13 points on average. Districts that are drawn to be too close could in fact flip to be won by Democrats. This could lead to as few as 13 Republicans in the Texas delegation. That kind of accidental backfire effect is what my academic collaborator Bernie Grofman has called a dummymander. I'm not saying this is going to happen, but it is possible. As the financial saying goes: pigs get fat, but hogs get slaughtered.

Redistricting Texas is unlikely to help Republicans for a simple reason: the existing Congressional plan is already gerrymandered. An attempt to redraw it even more aggressively might cut margins too close. Under a pro-Democratic swing, up to a dozen safe Republican seats would be put at risk.

The Current State of Texas's Congressional Map

In 2022, Texas Republicans prepared a Congressional plan that gave them three to five more seats than neutral map-drawing principles would produce. The Princeton Gerrymandering Project gave this plan a failing grade.

(By the way, PGP has scored congressional and state legislative maps in all fifty states. Check it out, as well as a deep dive into how states get A’s and B’s, by Zachariah Sippy and me.)

The existing map generates 25 Republican and 13 Democratic seats. Trump and his allies might be heartened by the fact that Trump got more voters than Harris in 27 districts, with massive swings among Hispanic voters along the southern border and the Rio Grande Valley. However, these districts did still elect Democratic congressmen.

This plan is bombproof to swings in opinion in either direction. Special elections (i.e. held at times other than November) often presage what will happen in the next national election. In special elections since January 2025, Democrats have outperformed their past margins considerably, exceeding their 2024 Presidential vote margin by 13 points. But even with a 13-point swing in vote margins, not a single seat would change hands under the current map.

Mid-decade dreams

Unlike most other states, Texas law does not limit redistricting to the year after the Census, when every state must meet the federal requirement of maintaining the same number of people across all districts. But Texas can redistrict any time, a type of transgression they pioneered in 2003. So although their mid-decade redistricting is anti-democracy, it is not actually illegal. How very Texas of them.

But it might also not be a smart move. To understand why this might backfire, we analyzed what such aggressive redistricting would actually produce.

We can simulate thousands or even millions of hypothetical maps by computer. This defines a neutral baseline, which PGP uses to determine whether a specific candidate plan is an outlier. Here is how the current Texas map stacks up.

On average, simulations based on party-blind principles produce maps that elect 17 Democrats out of 38. But the current map produces only 13 Democratic seats based on 2020 voting patterns, and in real elections in 2024 that is exactly what happened.

We decided to see how Trump’s suggestion would play out, in the form of hypothetical new maps. Here I analyze maps drawn by Neil Dixit of Palo Alto, California. If you have your own extreme gerrymander, please be in touch!

How much juice is left in the lemon?

The basic question is whether, as demanded by Trump, a plan can be drawn that adds five safe Republican Congressional seats on top of the current plan.

To do this, Republicans will face three challenges: geographic, legal, and electoral.

The first challenge is geographic. Since the current enacted plan has 24 safe (and 1 competitive) Republican seats, the goal would presumably be to draw at least 29 safe Republican seats. This would require packing Democratic votes into 9 extremely safe districts and splitting the remaining Democratic votes into powerless minorities across many Republican districts. This requires finding five Democratic districts to flip. We found 1 such district in the Dallas-Fort Worth area, 2 districts in Houston, 1 district in San Antonio-Austin, and 1 district in the Rio Grande Valley.

This leads to a second, legal difficulty. Redrawing these districts would require violating the existing interpretation of the Voting Rights Act, which calls for the construction of districts that would allow Hispanic populations in the two urban areas to elect candidates of their choice. Ultimately, the Supreme Court would have to allow that. So one necessary component of this scheme is to eliminate some current Voting Rights Act and Fourteenth Amendment protections. Considering the nature of recent Supreme Court decisions on voting rights, this legal hurdle is probably surmountable.

But the third challenge is hardest: making the resulting districts safe for Republicans. The new districts will have to include suburban and exurban areas around the urban regions mentioned above. Those regions swing in their partisan preference more than the nation as a whole.

For example, see CD3 through CD21 in Neil’s hypothetical map.

In 2024, Trump won these 19 districts by 6 to 16 points, in part because of his increased appeal among Hispanic populations. The map above shows the 2020 Presidential vote, which comes closer to capturing how they would likely perform at the Congressional level. The pink and light blue shading indicates competitive districts. There are a lot of them.

A backfire effect of up to a dozen seats

If opinion swings against Republicans in 2026, many of these districts might go Democratic. For example, in the 2018 Senate race, Beto O'Rourke won more votes than Senator Ted Cruz in five of them. That would undo all the expected benefits of a new map, and Republicans would be back at square one.

In our hypothetical plan, up to 19 districts, fully half of the Texas map, would have races with margins within 7 percentage points or less. Defending these newly competitive districts would potentially cost tens of millions of dollars that could otherwise be spent elsewhere.

Should Democrats follow suit?

The threat of a new Texas map has triggered a tit-for-tat war with Democrats around the country. California Governor Gavin Newsom has floated the idea of redrawing the California map, and New Jersey Governor Phil Murphy has done the same.

However, mid-decade redrawing in California and New Jersey is against the law in those states. Worse yet, such repeal efforts might potentially also undo the progress that has been made in state legislative redistricting. Unlike Congressional gerrymanders, a legislative gerrymander in one state is not counterbalanced by a gerrymander in another state. In that regard, squeezing out a few seats might produce worse representation within each state.

References:

Current map: (DRA) (Excel spreadsheet exploring scenarios)

An add-five-seat gerrymander for Republicans: (DRA) (Excel) (the example discussed above)

Another example of an extreme gerrymander: (DRA) (Excel)

In the 2024 Congressional election, gerrymandering plays a more limited role than it did ten years ago. With more independent commissions and state-level court actions, some of the worst excesses have been trimmed down. As a result, the net advantage to either party at the national level is reduced.

In 2013, I estimated that the total effect of partisan gerrymandering was so extreme that Democrats could win the national vote by 7 points and still not end up controlling the House of Representatives. That’s no longer true. Roughly speaking, this November whichever party wins more votes will likely gain control of the House. The risk of minoritarian rule is still there, but it’s reduced considerably.

An injustice against one is still an injustice against all

However, that doesn't change the fact that in specific states around the country, competition is still stifled because of how the lines are drawn. Even though Congressional gerrymanders committed by Democrats and Republicans cancel each other out somewhat this year, those offenses still remove competition wherever they occur. And in the case of legislative gerrymandering, voters are disenfranchised from decisions that affect them directly.

The Princeton Gerrymandering Project has catalogued such offenses using its report card system. Today I will show you ten of the worst remaining Congressional gerrymanders.

It’s not just about shapes

People think of gerrymanders as consisting of funny-shaped individual districts. But that’s not true. A clever expert with mapping software can lasso voters wherever they live, and those districts sometimes even look superficially OK. Also, these days gerrymandering is not a single-district offense. Instead, the offense arises from skew in the statewide plan as a whole.

Cracking cities

A fundamental tool of gerrymandering is cracking, the practice of splitting a community to take away its influence. This year, multiple cities have fallen victim to this particular strategy.

1. Tennessee’s Fifth (and Sixth and Seventh) Congressional District. Nashville has been traditionally contained with a single congressional district. But Tennessee legislators split the old TN-05 three ways, removing the ability of this city of nearly 700,000 people to send someone to Congress.

   

2. Utah’s Fourth Congressional District. Greater Salt Lake City is an island of blue in a sea of red. Traditionally, it has been enclosed within a single district, which has led Democrats to have one of Utah’s Congressional seats. But this time, legislators trampled a newly-established citizen commission to spread Salt Lake City across all four districts of the state. A recent state Supreme Court ruling could return power to the commission, and Salt Lake City could gain representation once again.

   

3. Nevada’s First Congressional District. Cracking can also be used to split ethnic communities. Nevada Democrats used highways as artificial boundaries to distribute Hispanic voters between two districts, giving them partisan influence but removing their ability to vote as a unified group.

   

Funny shapes and rural snakes

Sometimes gerrymanders take the more familiar form of convoluted shapes.

4. Ohio’s Fifteenth Congressional District. A politician-based commission drew a map that could make as many as 13 out of 15 Ohio House seats Republican. But if voters pass a constitutional amendment in November to take away their power, an independent citizen commission could redraw Ohio's Fifteenth - and every other district in the state.

   

   5/6/7/8. Texas Seventh, Ninth, Eighteenth, and Twenty-Ninth Congressional Districts. It is impossible to pick one favorite district here. Houston has expanded in several directions, with burgeoning Asian and Hispanic populations. The partisan redistricting commission has managed to pack heavily Democratic communities into these four districts, thus allowing the nearby Second and Thirty-Eighth Districts to be safely Republican.

   

   9. North Carolina’s Sixth Congressional District. In 2022, a state Supreme Court struck down a partisan gerrymander, putting in place a much fairer map. But the election of several Republicans to the court that fall led that court to reverse itself. At that point the legislature promptly passed a new plan that is likely to elect at least 10 Republicans out of 14 seats in this 50-50 state. Here, the Sixth District is nestled between Winston-Salem, Greensboro, and Charlotte to create a safe Republican district.

   

10. Illinois’ Thirteenth Congressional District. Rounding out our list is this specimen, which manages to go all the way from East St. Louis to Urbana-Champaign, combining an urban community, a college town, and a few strays along the way to create a safe Democratic district.

Hope for the Future

Some of these offenses could get undone, as early as next year. If Ohio voters pass Issue One, a citizen commission will redraw the map there and undo the statewide partisan gerrymander. And if Utah’s citizen commission is allowed to get on with its work without interference from the legislature, they can undo that offense as well.

To learn more about Ohio reform, see the Electoral Innovation Lab’s 2023 report.

Finally, in future years, gerrymandering in Nevada and Illinois could be outlawed directly by citizens. In those states, ballot initiatives can amend the constitution to take the redistricting power away from legislators.

To learn more about how voters can make democracy work better across the nation, see Vote Maximizer. Also, support Vote Maximizer!

February 23, 2024: updated to include odd-numbered Senate districts that might need an election this year.

Today, the most extreme legislative gerrymander in the nation was undone. The Wisconsin Supreme Court’s current redistricting case led to submission of six sets of remedial maps for the court’s consideration. But rather than wait for the Court to choose among them, the legislature and Governor Tony Evers agreed on his submission, and today he signed it into law.

Faced with the certainty that one of the maps would be adopted by the Court, the Republican-controlled General Assembly took matters into its own hands. I can identify two plausible reasons why they did so: (1) It leaves them a little more residual partisan advantage than the alternatives, and (2) it guarantees them two more years of control in the Senate, assuming that the Wisconsin Supreme Court takes no further action.

A few weeks ago I reported a deep dive by the Princeton Gerrymandering Project/Electoral Innovation Lab into the newly enacted proposal. I will use that analysis to put today’s news into a larger context.

The General Assembly makes the best of it

There’s been some discussion of a possible trick hidden within the General Assembly’s action, such as a hidden avenue for filing a new lawsuit. That concern might be overblown. There is so much distrust in Madison that counteroffers are met with suspicion. A simpler explanation is that the Governor’s plan was the best offer on the table, and they wanted to lock it in.

Consistent with our previous analysis at the Electoral Innovation Lab, court-appointed special masters concluded that four of the litigants submitted plans that met the court’s criteria: Governor Evers, the Wright petitioners, Senate Democrats, and the Clarke/LawForward petitioners. In our analysis, the Wright map and the Law Forward map would have been most evenhanded between the major parties. The Evers proposal contains some residual Republican advantage. That’s the first way in which the General Assembly made the best of an unfavorable situation.

A (mostly) majoritarian Assembly in 2024

One simple measure of treating the parties equally is the difference in partisanship between the median district and the statewide average. This is called the “mean-median difference,” and it’s an effective way to measure partisan bias in a 50-50 state like Wisconsin. It is simple to calculate and has a clear interpretation: If the mean-median difference is zero, then half the districts are above average, and whoever gets a majority of the vote should also win a majority of the legislature. As the mean-median difference deviates from zero, one party develops a substantial advantage.

The mean-median difference is closely related to the expected number of seats. Here is the relationship for the Assembly:

As you can see, compared with the other compliant submissions, the Evers plan is closer to the Law and Liberty and Legislative GOP plans, which the special masters identified as partisan gerrymanders.

Another way to interpret the mean-median difference is to ask: what’s the probability that a party who wins a majority of the statewide vote will also win a legislative majority? We can do that by assuming that each party’s statewide vote share will vary somewhere within the range of 46% to 54%.

In Wisconsin, because of the clustering of Democratic and Republican voters in different regions of the state, one might expect it to be difficult to simultaneously maximize partisan symmetry and minimize geographic splits. However, Governor Evers came close with mean-median differences of 1.7% (104 splits) in the Assembly and 1.0% (68 splits) in the Senate. For these reasons, the Princeton Gerrymandering Project gives an A grade to both the Assembly and Senate plans.

Let’s translate this into actual election performance.

In the Assembly, if Republicans get more votes, they will win a majority 95% of the time. If Democrats get more votes, they will win a majority about 60% of the time.

The Senate plan is better: if Republicans get more votes, they will win a majority more than 90% of the time. If Democrats get more voters, they will win a majority about 75% of the time.

That is pretty symmetric. However, in the Senate, there’s a catch.

A majoritarian Wisconsin Senate…but not until 2026

The Wright petitioners’ plan had superior partisan symmetry in both Assembly and Senate. In the Senate, their plan had a second advantage: it leveled the playing field immediately. The reason is that even-numbered districts all come up for election in 2024. According to their own analysis, those districts were arranged so that the chamber as a whole would become majoritarian in that first election.

Governor Evers does not make this claim for his plan. In the Evers plan’s even-numbered districts, 8 of them lean Democratic by seven points or more, 6 districts lean Republican, and two are competitive and could go either way. There is one more Democratic-leaning odd-numbered district (SD17) that may have to have an election (see below). Because it takes two cycles for the entire Senate to turn over, the Senate under his plan will likely have 17 to 19 Republicans (out of 33 districts total) after the 2024 election, even if they lose the statewide vote. And the Senate will not become fully majoritarian until 2026. So Republicans will likely hold on to their Senate majority for at least two more years.

The Wisconsin Supreme Court could conceivably require that the new Senate map be used to elect all 33 senators this November. At a minimum, Wisconsin law (Wis. Stat. § 17.03(4)(b)) says a legislative office is vacant when the “incumbent ceases to be a resident of … the district from which elected,” which seems to imply that some of the odd-numbered districts that would normally come up in 2026 might become open for this November’s election. For now, that potentially includes Senate districts 1, 17 and 19, as documented in a brief from the Legislature. This depends in part on whether incumbents who live within the old boundaries of those districts choose to move. Finally, redistricting has been said in the past not to create Senate vacancies, but the Attorney General could weigh in on that.

The Wisconsin legislature and governor failed to agree on Assembly and Senate maps in the state Supreme Court’s current redistricting case. So the Court invited parties to provide potential maps. Last Friday afternoon, seven sets of maps were submitted for consideration.

Here I report on a deep dive by the team here at the Princeton Gerrymandering Project/Electoral Innovation Lab into these seven sets of maps. We applied a modified version of our grading system to assess the plans according to the Court’s own criteria.

PGP analytics have previously identified the Court-overturned maps as the most extreme legislative gerrymander in the nation. The maps allow fewer than 50% of voters, if they vote Republican, to nonetheless elect a majority and even a supermajority in the Assembly and the Senate.

The Wisconsin Supreme Court, led by a new liberal majority, struck down both the Assembly and Senate maps, noting that they violate a constitutional requirement that districts be contiguous. Judging the maps based on contiguity had two advantages. First, the offense could be judged unambiguously with ease. Second, citing the state constitution potentially avoids review in federal court. Whatever the reason given, the maps must now be redrawn.

The Court rejected plans submitted by amicus District Solutions/Petering/FastMap, stating that it will only consider maps drawn by parties to the lawsuit. That limits the Court’s choices to the remaining six plans: Governor Evers, the Wright petitioners, Assembly Republicans, Senate Democrats, Clarke petitioners (LawForward), and Johnson intervenors (Wisconsin Institute for Law and Liberty).

Three of these choices appear to meet the Court’s criteria, with various strengths and weaknesses.

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Criteria for new maps: splits and partisan symmetry

The Court listed criteria (link to opinion) that it would use to evaluate remedial maps:

1. Federal requirements for equal population as well as compliance with the Equal Protection Clause and the Voting Rights Act.

2. The Wisconsin constitution’s requirements for contiguity and compactness.

3. Minimizing the degree to which counties, municipalities, towns, and wards are split.

4. Absence of bias toward either political party.

In addition, the court stated that it would consider preservation of communities of interest.

Regarding partisanship, the Court noted that as a judicial body it cannot favor one political party over another. Therefore a remedial map should show as little favor to either Democrats or Republicans as possible. This is highly significant: meeting this criterion opens the way to Wisconsin’s first representative legislature in decades.

All seven plans meet requirements #1 and #2 above. They repair the original problem of noncontiguous districts. All Assembly and Senate plans have similar compactness scores (average Reock score between 0.41 and 0.44, with the exceptions of the Petering/FastMap Assembly plan at 0.49, and the Legislative Republicans’ Assembly plan, which scores most poorly at 0.38). And all seven plans, both Assembly and Senate, have district populations that stay within 2% of the average, within the range cited in examples by the Court as acceptable.

The key criteria: geographic splits and partisan balance

This leaves two criteria where the plans differ meaningfully: geographic splits (#3), and partisan bias (#4). Here is how we quantified them.

Geographic splits. The same part of the state constitution used to strike down noncontiguous districts also specifies not splitting governmental jurisdictions:

The Court said it would allow some splitting, but that it prefers fewer splits.

Partisan symmetry. The court did not specify particular criteria for how it would evaluate partisanship. Here I will use a simple measure, the difference in partisanship between the median district and the statewide average (the “mean-median difference”).

The mean-median difference is an effective way to measure partisan bias in a 50-50 state like Wisconsin. It is simple to calculate and has a clear interpretation: If the mean-median difference is zero, then whoever gets more than 50% of the votes likely also gets 50% of the seats. Conversely, as the mean-median difference starts to get larger, one party develops a substantial advantage.

The mean-median difference is closely related to the expected number of seats:

One simple concept underlying the concept of partisan symmetry is the following: if one party gets a majority of the vote, in a partisan-symmetric plan it will also win a majority of the legislature.

To help interpret the mean-median difference, I will give an estimate of the probability that a party who wins a majority of the statewide vote will also win a legislative majority, assuming that each party’s statewide vote share will vary somewhere within the range of 46% to 54%.

The Princeton Gerrymandering Project’s grading system for a districting plan usually relies on both computer simulations and a measurement of partisan symmetry. Because the Court mentioned only avoiding partisan advantage, PGP’s grades for the seven sets of remedial Wisconsin plans will be determined using only partisan symmetry. (We still used the computer simulations to evaluate other grades on the report card such as compactness and competition.)

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Two easy graphs

Senate plans

To visualize differences among the plans, here is a scatter plot of mean-median difference vs. splits for the Senate plans. If one separates the plans by the Democratic/progressive side (blue x's) vs. the Republican/conservative side (red x's), a pattern emerges.

Of these Senate plans, those with a mean-median difference closest to zero came from Senate Democrats, the Wright Petitioners, and Governor Evers.

For the five petitioner/Democratic plans in the lower left (blue x’s) and the Petering/FastMap plan (empty circle), there’s a pretty clear tradeoff between splits and partisan symmetry. Basically, more splits move the advantage closer to zero - and even build a slight Democratic advantage.

Note the the red x’s, which indicate Republican/conservative plans. One has lots of splits and one has very few splits. But in both cases, the partisan asymmetry is quite large. These plans appear not to be engaging in a tradeoff.

Assembly plans

Here is the corresponding graph for Assembly plans.

Of the admissible plans, the Wright Petitioners have a mean-median difference that is closest to zero.

Now let’s grade the plans.

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Grading The Plans

Assembly Republicans: Addressing contiguity issues only

Assembly Republicans took the stance that they should make the fewest changes necessary to make districts contiguous. They did this - but along the way, they split dozens of governmental units. In the Marquette analysis, the overturned plan has 50 municipal splits and no ward splits, whereas the Assembly Republicans’ plan has 114 municipal splits and 117 ward splits. This is more than three times as many splits as the least-split plans. Indeed, the Assembly Republican plan has more splits than any two other plans combined. Their plans are also the least compact of all seven offerings.

Unsurprisingly, these plans retain the partisan advantage in the overturned maps: in the Assembly, favoring Republicans by 6.7% (overturned map was 6.3%), and in the Senate, 6.2% (was 5.6%).

Probability of a majoritarian Assembly or Senate: 100% if Republicans get more votes, 0% if Democrats get more votes.

Princeton Gerrymandering Project grades: Assembly, F. Senate, F. (click links for report cards)

If Republicans had chosen, they could have followed the lead of the Johnson intervenors, who were helped by the Wisconsin Institute on Law and Liberty, a conservative think tank. Law & Liberty’s plans have very few splits, yet retain nearly the same partisan advantage as the Assembly Republicans: a mean-median difference of 4.7% in the Assembly and 5.5% in the Senate. They also have twice as many competitive seats as the Assembly Republicans’ plan. Because PGP’s grading rubric gives a bonus for competition, the Law & Liberty Assembly and Senate maps get a grade of “C.”

A partisan-fair map that divides communities: District Solutions

One disallowed outside contribution came from District Solutions, a private company. They offered plans drawn by an algorithm called FastMap. Their plans achieve partisan balance (mean-median differences of 0.0% in the Assembly and 0.7% favoring Democrats in the Senate) and are geographically more compact than any other plan.

However, FastMap seems not to put much value in preserving government boundaries. The District Solutions maps divide communities almost as much as the legislative Republicans’ maps, with 157 splits in the Assembly map and 107 splits in the Senate map. Among other things, this cuts up the Madison area into pie slices:

Probability of a majoritarian Assembly: >90% if Republicans get more votes, >90% if Democrats get more votes. Grade: A for partisan fairness, F for splits.

Probability of a majoritarian Senate : 80% if Republicans get more votes, >95% if Democrats get more votes. Grade: A for partisan fairness, C for splits.

But is such a community-blind approach really necessary to achieve partisan symmetry? As it turns out, no.

Partial credit: Senate Democrats take care of their own chamber

The plan offered by Senate Democrats gets partway to partisan symmetry. It gets rid of a bit more than half the partisan bias in the Assembly (mean-median difference of 2.8%) and all of the bias in the Senate (mean-median difference of 0.1%). It appears that Senate Democrats were particularly attentive to their own chamber.

The plans have quite a few splits, though. The only plans with more splits are the Legislative Republicans’ and the District Solutions maps. Also, the Assembly plan has very few competitive districts. Overall, these plans have some significant weaknesses.

Probability of a majoritarian Assembly: >95% if Republicans get more votes, 30% if Democrats get more votes. Grade: B. Competitiveness grade: F.

Probability of a majoritarian Senate: >90% if Republicans get more votes, >90% if Democrats get more votes. Grade: A. Competitiveness grade: A.

Finally, we get to two plans that appear to meet all the Court’s criteria.

Wright Petitioners & Governor Evers: Having their cake and eating it too?

In Wisconsin, because of the clustering of Democratic and Republican voters in different regions of the state, one might expect it to be difficult to simultaneously maximize partisan symmetry and minimize geographic splits. That may be true, but the Wright Petitioners (Assembly, Senate plans on PGP) and Governor Evers (Assembly, Senate) come closest.

Both of these parties offered maps that had quite small mean-median differences: 0.9% (Assembly) and 0.8% (Senate) in the Wright petitioners’ plans, and 1.7% and 1.0% in Governor Evers’s plans. The Wright petitioners got their better mean-median differences with slightly more splits (115 and 71) than Governor Evers (104 and 68).

In the Wright map, unlike the FastMap plan, Madison is now maintained whole:

and the same is true for Governor Evers’s map:

Wright plan probability of a majoritarian Assembly: >90% if Republicans get more votes, 80% if Democrats get more votes. Grade: A.

Wright plan probability of a majoritarian Senate: >90% if Republicans get more votes, 80% if Democrats get more votes. Grade: A.

Evers plan probability of a majoritarian Assembly: >95% if Republicans get more votes, 60% if Democrats get more votes. Grade: A.

Evers plan probability of a majoritarian Senate: >90% if Republicans get more votes, 75% if Democrats get more votes. Grade: A.

The Clarke petitioners strike a different balance

If the Court wants to give more weight to splits instead of partisan fairness, another option is the Clarke petitioners’ map, prepared with LawForward. This plan has an exceptionally small number of splits for both the Assembly and Senate plans, on a par with the Johnson/Law & Liberty maps.

The Clarke plan does not go as far as the Wright or Evers plans in addressing partisan symmetry, with mean-median differences of 1.2% in the Assembly and 2.4% in the Senate. These values open a greater possibility of a countermajoritarian outcome, in both cases favoring Republicans.

Clarke plan probability of a majoritarian Assembly: >90% if Republicans get more votes, 70% if Democrats get more votes. Grade: A.

Clarke plan probability of a majoritarian Senate: >95% if Republicans get more votes, 40% if Democrats get more votes. Grade: A.

Conclusion

Finally, a summary of how the various plans rank. The Wright petitioners score very well on partisan symmetry. Factoring in splits, the plans from Governor Evers and the Clarke petitioners also rank highly.

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Many thanks to Ethan Arsht (Electoral Innovation Lab) and Setu Loomba (Princeton Gerrymandering Project) for calculations, graphics, and report cards, and to John D. Johnson (Marquette Law) for the calculation of municipality and ward splits. An earlier version of this post was posted on Twitter.com. This post was edited on January 19 to correct the list of plans that will be considered by the court.