A mid-decade battle over congressional redistricting is playing out in state capitals, in courtrooms, and on the ballot.

The efforts to redraw U.S. House districts for partisan advantage got jump-started when President Donald Trump called upon Republican-led Texas to reshape districts so that the GOP could win more seats in next year's elections.

Since then, lawmakers in Democratic-led California and Republican-led Missouri have approved revised districts, and officials in more states are considering it. Utah's Republican-led Legislature endorsed an altered congressional map Monday — though in response to a court order, not Trump's demands.

U.S. House districts typically are redrawn once a decade, immediately after a census. But some states have no prohibition on doing it more frequently. And the U.S. Supreme Court has said there is no federal prohibition on political gerrymandering, in which districts are intentionally drawn to favor one party.

The stakes are high, because Democrats need to gain just three seats in the 2026 elections to take control of the House, which would allow them to impede Trump's agenda. The president's party historically has lost seats in midterm elections, a fate Trump is trying to avoid.

Here's what's happening on redistricting, state by state:

Texas. Federal judges in Texas are considering a legal challenge to new congressional districts passed at Trump’s urging during a special legislative session in August. Civil rights groups and dozens of Black and Hispanic voters contend the new map intentionally reduces minority voters’ influence in violation of the 1965 Voting Rights Act and the U.S. Constitution. They want to prevent the new districts from being used. Republicans hold 25 of the 38 congressional seats in Texas. The revised map could give Republicans a shot at picking up five additional seats in next year’s elections.

California. California voters are deciding on new House districts. Voting began on October 6 in advance of a Nov. 4 election that will determine whether new congressional districts are implemented. Democrats already hold 43 of California’s 52 seats. But after Texas undertook redistricting, Democratic Gov. Gavin Newsom urged California lawmakers to reciprocate. They did so by passing a revised U.S. House map that could give Democrats a chance to gain five additional seats. Unlike Texas, California has an independent citizens’ commission that handles redistricting after the census. So any changes to the map need voter approval.

Missouri. After Texas and California took action, Missouri lawmakers joined the redistricting battle by passing a revised U.S. House map designed to give Republicans a shot at winning seven of the state’s eight districts — one more than they currently hold. The map targets a seat held by Democratic Rep. Emanuel Cleaver by stretching the Kansas City-based district into rural Republican areas and reducing the number of minority voters. Opponents are pursuing a referendum petition that, if successful, would force a statewide vote on the new map. Opponents also have filed several lawsuits asserting that mid-decade redistricting isn't allowed under the state constitution.

Utah. Utah's Republican-led Legislature passed a revised U.S. House map Monday that could give Democrats an improved chance at competing for a seat. Republicans currently hold all four of the state's seats. The revised map would place Democratic-leaning Salt Lake City in a single district that stretches into rural areas, instead of splitting the city among multiple districts. But the revision still must be reviewed by a judge, who is expected to approve a new map by November. A Utah judge in August struck down the House districts adopted after the 2020 census because the Republican-led Legislature circumvented an independent redistricting commission established by voters.

Kansas. Republican lawmakers who hold a supermajority in the Kansas Legislature have been gathering petition signatures from colleagues in an attempt to call a special session on congressional redistricting in November. They are taking that route because Democratic Gov. Laura Kelly is unlikely to call a special session.

Indiana. Republican Gov. Mike Braun has said that a legislative session on redistricting probably will happen, potentially as soon as November. Republican legislative leaders have met privately with Trump. But Braun has been waiting to call a special session until he is confident it will succeed.

Ohio. Ohio will have new U.S. House districts for the 2026 elections, though their shape remains to be determined. Republicans currently hold 10 of the state's 15 congressional seats. Ohio’s constitution requires new U.S. House districts because the ones adopted by Republican officials after the 2020 census didn’t have sufficient bipartisan support. If bipartisan consensus remains elusive, Republican lawmakers in November could adopt revised districts without need of any Democratic votes.

Maryland. Some Democratic state lawmakers have said they will file redistricting legislation for the 2026 session, and Democratic Gov. Wes Moore also has expressed support. “If we are going to have states in mid-cycle, in mid-decade, determining whether or not they have fair maps or not, then so will Maryland. Then, we should have that conversation, too,” Moore said last week. Democrats control seven of the state’s eight U.S. House seats and could target an eastern Maryland district held by Republican Rep. Andy Harris.

Louisiana. Revised districts in Louisiana hinge on a court case: The U.S. Supreme Court is scheduled to hear arguments Oct. 15 in a legal challenge to Louisiana's U.S. House districts, currently held by four white Republicans and two Black Democrats. A lawsuit contends state lawmakers wrongly used racial demographics when redrawing districts in response to a previous court ruling to give Black voters a better chance at electing the representative of their choice in two districts instead of one.

Florida, Illinois, and New York. These three highly populated states all have raised the possibility of redrawing U.S. House districts.

• Florida - Republican Florida House Speaker Daniel Perez has created a special committee to look into redistricting. Republicans currently hold 20 of the state's 28 seats.
• Illinois - Democrats already hold 14 of the 17 U.S. House seats in Illinois. But Democratic Gov. JB Pritzker has said it’s possible to redraw even more districts favoring Democrats.
• New York - New York has an independent commission that redraws districts after every census. State Democrats have introduced legislation to allow mid-decade redistricting, but the soonest new maps could be in place would be for the 2028 elections. That is because the proposal would require an amendment to the state constitution, a change that would have to pass the Legislature twice and be approved by voters.