Texas Republicans, at President Donald Trump’s urging, are preparing to redraw the state’s congressional map in a way that could flip up to five seats to the GOP in 2026. Trump hopes to boost Republicans’ chances of maintaining a narrow House majority amid the headwinds of the midterm election.
The manoeuvre in Texas would be legal and not unprecedented for the state, which also undertook a Republican-driven redistricting in 2003. But Democrats have called the move a partisan power grab and an affront to the traditional practice of drawing new congressional districts every 10 years, after a new Census.
But the debate over Texas’s electoral map has also prompted broader questions over the fairness of the way in which voting districts are outlined. And the one state bigger than Texas – California – has caught the attention of Vice President JD Vance.
“The gerrymander in California is outrageous,” Vance posted July 30 on X. “Of their 52 congressional districts, 9 of them are Republican. That means 17 percent of their delegation is Republican when Republicans regularly win 40 percent of the vote in that state. How can this possibly be allowed?”
So, does California have an unfair map, as Vance said?
By the numbers, California is not a dramatic outlier when it comes to the difference between its congressional and presidential vote. However, because this difference is multiplied by a large number of districts – since California is the United States’ most populous state – it produces a bounty of House seats beyond what the state’s presidential vote alone would predict.
Vance’s description of California’s map as a “gerrymander” is also doubtful – it was drawn by a bipartisan commission, not Democratic legislators. Gerrymandering is done by politicians and political parties.
Vance’s office did not respond to an inquiry for this article.
What the numbers show
Our first step was to measure the difference between each state’s House-seat breakdown by party and its presidential-vote breakdown by party, which is what Vance cited. (Our analysis builds off of a 2023 Sabato’s Crystal Ball story written by this author. Sabato’s Crystal Ball is a publication of the University of Virginia Center for Politics.) We removed from consideration any state with one, two or three House members in its delegation, because these small states have wide differentials that skew the comparison.
For red states won by Trump, we took the percentage of Republican seats in the House delegation and subtracted the percentage of the vote Trump won in that state. Conversely, for blue states won by Kamala Harris, we took the percentage of Democratic seats in the House delegation and subtracted the percentage of the vote Harris won in the state.
Our analysis found that California did elect more Democrats to the House than its presidential vote share would have predicted, but the state was not an outlier. With 83% of its House seats held by Democrats and 58% of its 2024 presidential votes going to Democrats, California ranked 13th nationally among 35 states that have at least four seats in their delegation.
California has the nation’s 13th widest difference between House and presidential results
The top 13 differentials were split roughly evenly between blue and red states.
In six states that have at least four House seats – red Iowa, Utah, Arkansas and Oklahoma, and blue Connecticut and Massachusetts – a single party controls every House seat, even though the winning presidential candidate won between 56% and 66% of the vote in those states.
Another six states had a differential equal to or wider than California’s: Red South Carolina and Tennessee, and blue Oregon, Illinois and Maryland, plus purple Wisconsin.
California does stand out by another measure, because of its size.
If you multiply the House-to-presidential differential by the number of House seats in the delegation, you get a figure for “excess House seats”, the term used in the 2023 Sabato’s Crystal Ball article – essentially, a majority party’s bonus in House seats beyond what presidential performance would predict.
Because California has a large population represented by many House districts, even its modest differential produces a lot of extra Democratic House seats – 12, to be exact. That’s the largest of any state; the closest competitors are blue Illinois and New York, and red Florida, each of which has more than four excess seats for the majority party.
Texas’s current congressional map has 3.7 excess seats for the Republicans. That would increase to an 8.7-seat GOP bonus if the GOP can flip the five seats they’re hoping for in 2026.
Is California a “gerrymander”?
Vance described California’s map as a gerrymander, but political experts doubted that this term applies. A gerrymander typically refers to a map drawn by partisan lawmakers, and California’s is drawn by a commission approved by voters specifically to remove the partisanship from congressional map drawing.
“California’s congressional map is no gerrymander,” said Nathaniel Rakich, a contributing analyst to Inside Elections, a political analytics publication. “It was drawn by an independent commission consisting of five Republicans, five Democrats, and four independents that is generally upheld as one of the fairest map-drawing entities in any state.”
Kyle Kondik, the managing editor of Sabato’s Crystal Ball, said commissions tend to produce a more competitive House battleground than a fully partisan system. Of the 19 House seats his outlet currently rates as toss-ups going into 2026, only two come from states where one party had a free hand to gerrymander the current district lines.
“I think it’s fair to say that commission and court-drawn maps can inject some competitiveness into the process,” Kondik said.
Because the seats were drawn by a commission, California has a lot of competitive seats. This helps California Republicans despite the state’s Democratic tilt.
According to the 2024 pre-election ratings by Sabato’s Crystal Ball, California had three Democratic-held seats in the “lean Democratic” category, and two more that were rated “likely Democratic”.
So, going into the election, five of California’s 40 Democratic-held seats are at least somewhat vulnerable to a Republican takeover. Texas Democrats aren’t so lucky, under its existing map: They are able to realistically target only one “likely Republican” seat out of 25 held by the GOP.
Sometimes, geography is the enemy of a “fair” map
Despite map makers’ efforts, it is sometimes impossible to produce a map that jibes perfectly with a state’s overall partisan balance. The cold facts of geography can prevent this.
One oft-cited example is Massachusetts, which hasn’t elected a Republican to the US House since 1994. There are few Republican hotbeds in Massachusetts, and experts say they can’t be easily connected into coherent congressional districts.
“Especially in deep-red or deep-blue states, parties tend to get a higher share of seats than they do of votes,” Rakich said. “Imagine a state where Republicans get two-thirds of the vote in every district; obviously, they would get 100 percent of their seats.”
Rakich said Democrats are geographically distributed more favourably in California. But in other states, Republicans benefit from better geographic distribution.
“I haven’t heard Vance complain about the fact that Democrats only get 25 percent of Wisconsin’s congressional seats despite regularly getting 50 percent of the vote there,” Rakich added.