Democrats got a potential boost for the 2024 congressional elections as courts in Alabama and Florida ruled recently that Republican-led legislatures had unfairly diluted the voting power of Black residents.

But those cases are just two of about a dozen that could carry big consequences as Republicans campaign to hold onto their slim majority in the U.S. House of Representatives. Another trial alleging racial violations in voting districts got underway Tuesday in Georgia, where Democrats also hope to make gains, while voting rights advocates in Ohio decided to drop a legal challenge to that state’s congressional districts — providing a bit of good news for Republicans.

Legal challenges to congressional districts also are ongoing in Arkansas, Kentucky, Louisiana, New Mexico, South Carolina, Tennessee, Texas and Utah. And new districts seem likely in New York and North Carolina, based on previous court actions.

Though much remains to be settled, there’s a good chance congressional districts will be changing in numerous states.

It’s likely that “a significant number of voters will be voting for a different person than they voted for in 2022,” said Doug Spencer, an election law professor at the University of Colorado who manages the All About Redistricting website.

Republicans currently hold a 222-212 majority in the U.S. House, with one vacancy in a previously Democratic-held seat.

Boundaries for the nation’s House districts were redrawn in all states before the 2022 election to account for population changes noted in the 2020 census. In some states, majority party lawmakers in charge of redistricting manipulated lines to give an edge to their party’s candidates — a tactic known as gerrymandering. That triggered lawsuits, which can take years to resolve.

The court battle in Alabama, for example, already has lasted about two years since the legislature approved U.S. House districts that resulted in six Republicans and just one Democrat, who is Black, winning election in 2022. In June, the U.S. Supreme Court upheld a lower court’s finding that the map likely violated the federal Voting Rights Act by failing to provide Black residents — who comprise 27% of the state’s population — an opportunity to elect their preferred candidates in two districts.

Alabama lawmakers responded in July by passing a revised map that maintained only one majority-Black district but boosted the percentage of Black voters in a second district from about 30% to almost 40%. A federal judicial panel on Tuesday decided that wasn’t good enough. But Republican Attorney General Steve Marshall’s office said it will again ask the U.S. Supreme Court to review that decision.

Ongoing lawsuits in Georgia and Louisiana are using similar arguments to push for additional districts where Black voters could have more power. Democrats stand to gain because a majority of Black residents tend to vote for Democrats instead of Republicans.

A Florida redistricting case decided Saturday by a state judge also involved race, though it relied on provisions in the state constitution instead of the Voting Rights Act. That judge said the U.S. House map enacted by GOP Gov. Ron DeSantis diminished Black voters’ ability to elect their candidate of choice in northern Florida. The judge directed Florida lawmakers to draw a new congressional map — a ruling that is likely to be appealed before it’s carried out.

The litigation in southern states is “more of a racial representation issue than it is a political representation issue,” said Michael McDonald, a political science professor at the University of Florida who specializes in elections and redistricting. “But we can’t escape the political consequences, because we have a very closely balanced House of Representatives at the moment.”

Though Democrats stand to gain from court challenges in Alabama, Florida, Georgia and Louisiana, Republicans appear poised to pick up seats in North Carolina, which also has experienced a series of legal twists.

North Carolina currently is represented in Congress by seven Democrats and seven Republicans after the state Supreme Court — under a Democratic majority — struck down the Republican legislature’s map as an illegal partisan gerrymander and instead allowed a court-drawn map to be used in the 2022 election.

While that case was on appeal to the U.S. Supreme Court, voters elected a Republican majority to the North Carolina Supreme Court. Those judges in April reversed the previous ruling and declared there was no constitutional prohibition on partisan gerrymandering. The state’s GOP-led legislature is expected to pass new districts that favor their candidates before the 2024 election.

A similar reversal could benefit Democrats in New York, where a state appeals court in July ordered an independent redistricting commission to start work on a new set of U.S. House districts that could be used in the 2024 election.

The New York commission had failed to reach a consensus before the 2022 election, leading to maps drawn by the Democratic-led legislature that were struck down as an unconstitutional gerrymander and replaced with court-approved maps. Republicans fared better under those maps, picking up several suburban New York City seats that could be put back into play if the districts are redrawn again.

Political observers also had been keeping an eye on Ohio, where the state Supreme Court previously ruled that Republican-drawn maps were unconstitutional. Despite that, those districts were allowed to be used in the 2022 election, and Republicans won 10 of the state’s 15 U.S. House seats.

The U.S. Supreme Court in June ordered the state court to take another look at the case. But voting rights groups on Tuesday told the state court that they are willing to accept the current districts in order to avoid “the continued turmoil brought about by cycles of redrawn maps and ensuing litigation.”

Though lawsuits have become common after each decennial redistricting, they can lead to confusion among voters if congressional districts get changed after only a few years.

“It does undermine a little bit the theory of representative democracy if you don’t even know who represents you election to election,” Spencer said. “It’s another reason why these redistricting games are so problematic.”