A Supreme Court case, Louisiana v. Callais, being reargued Wednesday, could shift at least 19 Democratic-held congressional districts to Republican control. The case challenges Louisiana’s creation of a second majority-Black congressional district, questioning whether it violates the Fourteenth or Fifteenth Amendments, which protect equal voting rights and prohibit racial discrimination in voting.

Louisiana’s legislature redrew the map after lawsuits claimed the previous map weakened Black voters’ strength, violating the Voting Rights Act’s Section 2. The state argued it was forced to create the district or risk federal intervention. Opponents, led by Phillip Callais, claim the new map is an unconstitutional racial gerrymander.

The Court’s decision could impact congressional maps nationwide ahead of the 2026 midterms. Democrats worry the conservative 6-3 Court might side with Callais, undermining protections for minority voters. A report from Fair Fight Action and Black Voters Matter warns that a ruling against Section 2 could force redistricting in 19 Democratic districts, potentially favoring Republicans.

Key districts at risk include Alabama’s 2nd and 7th, both majority-Black and long-held by Democrats Shomari Figures and Terri Sewell, respectively. Louisiana’s 2nd and 6th districts, represented by Troy Carter and Cleo Fields, also face possible changes, threatening their Democratic leanings.

President Trump has expressed support for maintaining Republican control and may encourage states to pursue out-of-cycle redistricting to capitalize on the ruling. The outcome of Louisiana v. Callais could therefore reshape political power across the U.S. Congress.