How redistricting in 6 states could affect who controls Congress

Multiple states across the country are engaged in fights over redistricting -- and the outcomes could help determine whether Democrats or Republicans have control of the House in 2024.

The redrawing of congressional boundary lines happens every 10 years, following the completion of the census. Those results shift how many representatives each state gets depending on their population and which parts of each state get grouped together into districts that each elect someone to the House.

Depending on how those lines are drawn, districts can be designed to unfairly favor one party over the other based on information like historical voting patterns, voter demographics and voter registration. (Some states use independent groups during redistricting to decrease the chance of this.)

Three years after the last census, the dust is far from settled on congressional maps in some parts of the country.

As the 2024 election approaches, a series of high-profile court cases has brought redistricting in the spotlight once again. Here is a closer look at how the process is playing out in six states that have to -- or could soon -- redraw their maps.

Each seat currently counts in the House, where Republicans hold only a five-member majority.

Alabama

Delivering what advocates called an unexpected victory for Black voters last month, the U.S. Supreme Court ordered Alabama's Republican-led Legislature to redraw the state's congressional map in compliance with the Voting Rights Act (VRA).

The justices narrowly ruled that Alabama's current map violates Section 2 of the VRA by diluting Black voters' ability to elect a representative of their preference.

Black people make up more than a quarter of Alabama's population but have only one majority-Black district out of seven.

Experts believe the 5-4 decision could result in a one-seat pick up for Democrats in the House, because Black voters in Alabama are usually Democratic-leaning.

The six predominantly white districts are represented by Republicans.

Lawmakers now are convening in a special session to complete the new map by the July 21 deadline.

Louisiana

The Supreme Court's decision in Alabama might reverberate to other states across the South, paving the way for additional Democratic gains in the House. One such state is Louisiana.

Earlier this month, the Supreme Court allowed a VRA-related case regarding Louisiana's House map to move forward in the 5th U.S. Circuit Court of Appeals.

That case could potentially open the door for an additional majority-Black district -- in a state where a third of the population is Black -- if Louisiana's Republican-led Legislature is ordered to redraw the map.

Much like in Alabama, a second mostly Black district could lead to another win for Democrats given how Black voters in Louisiana historically vote.

Five of the state's six districts are predominantly white and represented by Republicans.

Georgia

Georgia also presents an opportunity for Democrats to pick up a House seat -- for a total of three -- in light of the Supreme Court's decision in Alabama.

After the high court's ruling came down in June, a Georgia federal judge asked the two parties in an ongoing VRA case regarding the state's congressional map to provide supplemental briefings.

As the case moves forward, there is the potential that Georgia may ultimately redraw its map with an added majority-Black district in a state, like Alabama and Louisiana, where Black residents are the largest minority group.

Last year, a federal judge allowed Georgia's current map to be used in the midterms because there was limited time to redraw ahead of the elections. The judge acknowledged, however, that the state's congressional boundaries are likely in violation of the VRA.

North Carolina

Unlike in the above states, Republicans are looking to pick up several seats in North Carolina during redistricting there.

GOP lawmakers hold a supermajority in the state Legislature, where they are set to redraw their congressional map imminently -- potentially yielding a net positive of up to four seats for their party, experts say.

North Carolina currently is represented by seven Democrats and seven Republicans. The existing map was created after the state Supreme Court narrowly found in 2022 that partisan gerrymandering was illegal.

The 2022 midterms elections though, saw the partisanship of the state Supreme Court flip to a Republican-leaning majority and the justices subsequently revisited the issue of redistricting, overturning the earlier decision and effectively giving lawmakers the green light to redraw the map as they see fit.

South Carolina

During its next term, the U.S. Supreme Court will hear a case about South Carolina's congressional lines based on the 14th and 15th Amendments, rather than the VRA.

Democrats are hoping the court will make a ruling similar to that in the Alabama case, which could lead to an additional majority-Black, Democratic-leaning district.

More than one in four South Carolinians is Black, but just one of the state's seven districts is predominantly Black. The six mostly white districts are represented by Republicans.

New York

In New York, the Democratic-led Legislature is confident that it will be able to redraw its congressional map ahead of the 2024 election cycle. According to observers, this could allow Democrats to gain up to seven seats.

The GOP currently holds 11 of New York's 26 congressional seats, but Democrats are trying to institute a map that could result in Republicans holding just three or four districts.

Controversy surrounded the state's initial map last year. Before the 2022 midterms, the court struck down a Democratic-drawn map, deeming it a partisan gerrymander. A third party then stepped in to draw the map, forcing longstanding incumbents to run against each other.

Democrats are now seeking permission from the court to draw their own districts rather than having to stick with the third-party map.

How this affects the next election

With several redistricting cases up in the air, Democrats and Republicans say they are looking ahead to 2024 with both hope and caution.

In an interview with ABC News, National Democratic Redistricting Committee President John Bisognano said that he anticipates 2024's House races will be just as competitive as those in 2022, with the majority coming down to a few seats.

He said his focus, however, is on how the redrawing of congressional boundaries can provide voters with increased opportunities to elect individuals who best represent them.

"I think that the House race in 2024 will remain razor thin, and every seat matters," he said.

"But I'd be more keen, in this instance, to focus on the reality that in those states voters are going to be able to elect a member of their choice rather than a party of their choice," he added, referencing the Supreme Court's Alabama ruling.

Adam Kincaid, the president of the National Republican Redistricting Trust, said in a statement to ABC News that it is "too early to tell" how redistricting cases will shake out for the House majority in 2024.

"There are dozens of lawsuits moving their way through the courts and the outcome of those cases is yet to be determined," he said.