The lines that mark U.S. congressional districts are re-drawn every decade based on population changes in a process known as redistricting. In at least seven states, how these lines end up could determine whether Democrats take congressional control away from Republicans who currently have a majority with 222 seats -- nine more than Democrats.

U.S. political parties have a long history of influencing the redistricting process to create complicated districts that favor their own party, known as gerrymandering. Several states are currently battling over their redistricting boundaries in court. See how it's shaking out.

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ALABAMA

In June, the U.S. Supreme Court ruled that the state's congressional boundaries violated the 1965 Voting Rights Act which prohibits discrimination based on race, color, or minority group. 

The ruling means Alabama's Republican-controlled state legislature must redraw the boundaries to be more equitable. 

Black voters currently make up 27 percent of the state but there is only one majority-Black district out of seven. All the other districts are represented by Republicans. 

The new map must be complete by July 21.

LOUISIANA

A similar lawsuit regarding Louisiana's redistricting is currently under deliberation in the 5th U.S. Circuit Court of Appeals. 

The state is 32 percent Black, yet five of its six congressional districts are majority white, held by Republicans. I

f the courts rule that Louisiana must also redraw its lines, the state could gain another majority-Black district in the U.S. Congress.

GEORGIA

Another lawsuit is under consideration by a federal judge in Georgia and may result in the state also having to redraw their lines. 

In the 2022 midterm elections, a federal judge said the state's boundaries likely violated the Voting Rights Act, but said it was too late to redraw them ahead of the vote, ABC News reports. 

Georgia is 30.5 percent Black, but only 5 of the 14 congressional districts are majority-Black. The rest are Republican controlled. 

If the lines are redrawn, another majority-Black district may also be added to the U.S. Congress.

NORTH CAROLINA

North Carolina currently has 14 congressional districts evenly split between Republicans and Democrats, after the state's Supreme Court found in 2022 that partisan gerrymandering was involved in the prior lines. 

The Republicans filed suit, and in June 2023, the U.S. Supreme Court upheld a ruling that found that North Carolina's redistricting plan was excessively partisan and that state courts can curb state legislatures decisions on redistricting. 

However, after the 2022 midterms, the state's Supreme Court got a Republican majority and the court voted to allow lawmakers in the overwhelmingly-Republican state legislature, to re-draw the lines. 

This means new congressional borders could be set any day now, and could result in four more Republican seats in the U.S. Congress, ABC News reports.

OHIO

In July 2023, the U.S. Supreme Court ruled that Ohio's Supreme Court has to reconsider a past ruling that Ohio's current congressional district lines are unconstitutional due to gerrymandering in favor of Republicans.

Currently only five of the 15 congressional districts are held by Democratic representatives. 

However, the state Supreme Court has a new makeup now which could approve the current lines that were previously rejected. 

The Republican-led legislature could even submit a new map that's even more favorable to Republicans, potentially gaining three additional Republican seats in the U.S. Congress.

NEW YORK

A lawsuit currently before New York's state appellate court could result in a redrawing of the state's 26 districts, 11 of which are held by Republicans.

The current lines were drawn by a third party after another court ruled that an initial Democratic-drawn map was too partisan. 

The majority-Democratic legislature is now hoping an appellate court ruling in their favor will allow them to redraw the lines and potentially gain seven U.S. Congressional seats.

SOUTH CAROLINA

The U.S. Supreme Court has agreed to hear in it's next term, a lawsuit alleging that South Carolina's districts violated the 14th and 15th Amendments of the U.S. Constitution -- equal protection and preventing denial of a citizen's right to vote based on race, respectively. 

The ruling could result in the state having to redraw its lines ahead of the 2024 election. 

South Carolina is 26.5 percent Black but only one of its seven districts is majority Black. The other districts are held by Republicans.

Some analysis say redrawing could result in one more majority-Black district in the U.S. Congress.

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