What is mid-cycle redistricting?
In August 2025, the Texas state legislature approved a new congressional map that created five seats, likely improving the odds that more Republicans would be elected to office. Texas currently has 38 congressional seats, of which 26 (64.8%) are held by Republicans; the new plan could shift the balance to 31/38 (81.6%). President Trump, the Republican candidate for President in 2024, received 56.1% of the popular vote in Texas. Similar efforts designed to help elect Republicans have succeeded in Missouri and North Carolina, and are underway in Indiana and Ohio.
On the Democratic side, California voters approved a new redistricting plan in November 2025 that would likely shift five congressional seats to Democrats. California’s congressional delegation currently has 43 Democrats and 9 Republicans (82.7% Democratic) and would shift to 92.3% Democratic under the new plan. President Trump received 38.3% of the popular vote in California in 2024. Mid-cycle redistricting designed to help Democrats get elected has also been discussed in Maryland, New York, and Virginia.
Why are states doing mid-cycle redistricting?
Two major forces make off-cycle redistricting possible and palatable for legislators. First, the Supreme Court’s Rucho v. Common Cause decision (2019) precludes the ability for courts to adjudicate federal partisan-gerrymandering claims. This change, in turn, leaves room for mid-decade redistricting. Second, narrow House margins mean that both parties see one or two additional seats as a big payoff.
How gerrymandered are state delegations?
The impact of gerrymandering, or partisan-led redistricting, can be seen by calculating the partisan difference score – the difference between the share of voters who selected a Republican president and the Republican share of a state's congressional delegation to capture the partisan tilt in a state's districts (and vice versa for Democrats). In general, gerrymandered states have large partisan difference scores (positive or negative).
The chart below compares these two variables across states. The dotted line shows the hypothetical relationship between Trump's 2024 vote and state delegation when the two percentages are exactly equal. For example, if a state has 10 legislators, Trump receives 50% of the vote, and the state has 5/10 or 50% Republican legislators. (States with three or fewer representatives are omitted.)
For example, when the Republican Party’s vote share falls below 50%, their seat percentage generally lags behind the popular vote. For example, Illinois has 17 congressional seats, and Trump received 43.5% of the vote, yet the delegation has only 3 Republican House members (3/17 = 17.6%). The Republican deficit stems from the Illinois state legislature, which is majority Democratic, and the Democratic Governor enacting a redistricting plan that strongly favored Democratic candidates.
On the flip side, when Republicans have significantly more than 50% of the vote, their seat share is generally much higher. For example, Oklahoma has 5 seats; Trump received 66.2% of the vote, and Republicans hold all 5 seats. Here, a Republican state legislature and Governor enacted a gerrymandering plan that favored Republican candidates.
How much more mid-cycle redistricting can we expect?
Three states have revised their maps or are holding a referendum to do so. Five other states (Connecticut, Arkansas, Iowa, Massachusetts, Oklahoma, and Utah) already have delegations that are 100% Democratic or Republican. The table below shows data on the remaining states, sorted by their partisan difference scores, along with the current composition of the state’s House delegations. The columns on the right show constraints: whether there is divided state government (no party controls both the state legislature and the governor’s office), whether the state has majority-minority districts because of the Voting Rights Act (a feature that complicates partisan redistricting efforts), whether the state Constitution bans mid-term redistricting, and whether the state uses a nonpartisan commission to redistrict.

The data in the chart suggests there is unlikely to be much additional mid-cycle redistricting in 2025. Most states face one or more of the four limitations. Only four states have no constraints: Illinois, Indiana, Maryland, and Ohio. And even in these cases, redistricting efforts can run into practical constraints. For example, Illinois’ partisan difference score shows that it is already highly gerrymandered, so it would not be easy to create additional Democratic seats.
The table also shows why partisans are focusing on states like Maryland and Indiana despite the relatively small seat gains (1 Democratic seat in Maryland and 2 Republican seats in Indiana). There are few other places to win seats through mid-cycle redistricting. The lone exception is Ohio, where Republicans could potentially pick up several seats.
The Takeaway
Mid-cycle redistricting gives parties a second chance to stretch their political advantage, testing how far they can push district lines to gain congressional seats.
Four states have already adopted mid-cycle redistricting plans, with several others in work.
Given current rules and seat shares, there is less potential for additional mid-cycle redistricting.
One wild card is a case before the Supreme Court that would remove Voting Rights Act mandates for majority-minority districts. If these restrictions are removed, several southern states would likely redistrict, shifting seats to the Republican Party. Although it is unlikely that these changes could be made in time for the 2026 midterm elections.












































































































































































































































