The unprecedented national Republican effort to reshape US House districts across the country failed on Tuesday, as the party's intended seawall was swept aside by a Democratic tsunami.

As of midday Wednesday, Democrats had either won or were leading in 12 of the 15 seats that Republicans redrew to become more conservative. To make matters worse, Republican redistricting may have inadvertently cost some of their own incumbents their seats in North Carolina and Tennessee by stretching their margins too aggressively.

The bleeding didn't stop there. In California, where the Democratic Party drew its own retaliatory map that took aim at five Republican seats, Democrats appeared likely to win all of those districts. Democrats also picked up a new seat in Utah, the result of a court-ordered redraw.

The upshot: Democrats were poised after Tuesday's elections to gain seats outright solely due to redistricting, a stunning reversal after Republicans seemed to have won the redistricting war decisively earlier this year.

"The only way to look at the Republican effort to gerrymander this country into oblivion to save their prospects in the House is to see it as a complete and utter catastrophe," said John Bisognano, the president of the National Democratic Redistricting Committee, which promotes Democratic redistricting efforts around the country.

A spokesperson for the National Republican Redistricting Trust, the Republican counterpart to the NDRC, did not immediately respond to an email seeking comment.

Redistricting typically only occurs at the start of each decade to incorporate population changes from the decennial US Census. Both parties have used the process to create more favorable districts, a practice known as gerrymandering.

Trump broke with historical precedent in 2025 when he urged Texas Republicans to approve a new mid-decade House map intended to flip five Democratic seats. Other Republican- and Democratic-led states soon followed.

The US Supreme Court's ruling in April hollowing out the Voting Rights Act cleared the way for several Republican-controlled Southern states to eliminate predominantly Black districts held by Democrats, as well. Meanwhile, Virginia Democrats' own aggressive new map was deemed illegal by state courts.

But the new Republican maps did not anticipate Tuesday's massive shift away from Trump's 2024 performance, driven by deep voter dissatisfaction with the war against Iran and his handling of the economy. Only 32% of Americans approved of the president's performance going into Election Day, according to Reuters/Ipsos public polling, near his lowest-ever level.

In the two biggest Republican redistricting prizes, Texas and Florida, Democrats appear to have retained eight of nine targeted seats. The dramatic swing toward Democrats among Hispanic voters proved decisive in several seats, including in south Texas, where Democrats held onto two heavily Latino districts that Republicans redrew.

In North Carolina, Republicans siphoned off Democratic areas from the seat of Democrat Don Davis in an effort to oust him from Congress. Instead, Davis won reelection, and Republican Greg Murphy, whose seemingly safely conservative district absorbed those Democratic voters, was barely ahead of his Democratic challenger, with votes still being tallied.

"If Murphy loses, that would be a classic 'dummymander,'" said Kyle Kondik, an elections analyst at the University of Virginia's Center for Politics, referring to a gerrymander that ends up costing a party seats.

Republicans had already redrawn North Carolina's House map ahead of the 2024 election, but Tuesday's results appeared to have transformed that gerrymander into a dummymander of its own, with Democrats poised to flip at least five and potentially six Republican seats in all.

In Tennessee, a Republican redistricting effort also appeared to backfire. The party split the mostly Black and Democratic city of Memphis into three Republican-leaning districts, aiming to unseat the state's lone Democratic US representative.

But the race in one of those new districts remained too close to call on Wednesday. Meanwhile, a seemingly safe Republican district near Nashville that lost some conservative areas in the redraw appeared likely to fall to Democrats, even though Trump carried it by 24 points in 2024.

In Alabama, where Republicans delayed primary elections to give themselves time to draw a new map aimed at unseating US Representative Shomari Figures, the Democratic incumbent won reelection anyway, helped in part by high turnout among Black voters.

Most political observers expect several states to consider a fresh round of redistricting ahead of 2028, though some of Tuesday's results could scramble the landscape.

Newly elected Democratic governors in Texas and Georgia would be able to block Republican efforts in those states, for instance. In Maryland, voters approved a constitutional amendment that paves the way for Democratic lawmakers to draw a new House map.