How the Texas gerrymandering battle could impact the midterms

The move by Texas to redraw the lines of its congressional districts has refocused attention on a practice nearly as old as the U.S. Constitution. In 1812, one of the drafters of that document, Elbridge Gerry, used his office as governor of Massachusetts to craft a new congressional district shaped like a salamander. The term “gerrymander” soon entered the vernacular, where it remains to this day.

The latest chapter in this long-running drama began in 2010, when Republicans’ carefully planned efforts to win majorities in state legislatures scored sweeping successes, allowing them to control the redistricting process that followed the 2010 census. As a result, the GOP was able to lock in its massive 63-seat gain in the 2010 midterm congressional elections and to win House majorities far in excess of their share of the popular vote.

In 2012, Republicans won 234 House seats, giving them a majority of 33—even though Democrats won 48.8% of the vote, compared to 47.7% for the GOP. This pattern persisted through Donald Trump’s victory in the 2016 presidential race.

Two years later, the record of disproportionate Republican wins in the House abruptly ended. Few noticed at the time, but in 2018 and again in 2020, the partisan balance in the House corresponded almost exactly to the shares of the national House vote won by the major parties.

In the redistricting battle that followed the 2020 census, Democrats and Republicans fought to a draw, and the partisan balance barely budged. In the 2022 midterm elections, Republicans’ 2.8 percentage point edge in the national popular vote would have given them 223 seats if their total had perfectly reflected this vote. Their actual total: 222 seats.

Despite Donald Trump’s popular vote win in the 2024 presidential election, the Republican edge in the House vote fell by 0.2 percentage points, and the GOP lost two seats, for a total of 220 and a razor-thin five-seat majority, again closely reflecting its national House vote share.

This is why recent developments in Texas could be consequential. If Gov. Greg Abbott and the large Republican majority in the state legislature can engineer a five-seat shift, then the GOP would in effect begin the 2026 midterm election with a baseline of 225 House seats and a majority that tripled from 5 to 15.

This would make it considerably more difficult for Democrats to overturn the Republican majority in the 2026 midterms. Here’s why.

In 2024, only 15 Republican members of the House won their races by less than 5 percentage points. If the 2024 baseline remains intact, Democrats would have to win only 3 of these seats to regain a majority. But if Texas shifts the baseline, as seems likely, Democrats would have to win 8 of these seats, a more daunting challenge. A seat-by-seat analysis shows that winning 3 Republican seats would require a net shift toward the Democrats of about 1 point in the national popular vote, while winning 8 seats would require a much larger gain of 2.5 points.

This analysis presupposes that Texas’s redistricting gambit will yield a net Republican gain of 5 seats. There are two reasons why it may not.

First, four of the new districts contain Hispanic majorities, an electorate in which Donald Trump scored large gains in 2024. But there is evidence that this pro-Republican tide may ebb. Recent surveys show that Hispanics are giving the Trump administration low marks for its handling of inflation and immigration, and House Republicans could pay the price next year.

Second, events in Texas have led several Democratic-held states, including California and Illinois, to consider new redistricting plans of their own. There are obstacles, such as California’s non-partisan redistricting commission, but it appears possible to overcome them.

What’s happening in Texas won’t stay in Texas. The redistricting battle may well go nationwide, with consequences that are impossible to predict.