The concern centers on Louisiana v. Callais, a case the justices are set to rehear on October 15. The outcome could determine the future of Section 2 of the Voting Rights Act, which prohibits redistricting plans that dilute the voting power of racial minorities.

Two prominent voting rights groups have warned that striking down or narrowing Section 2 would allow Republican-controlled legislatures to redraw as many as 19 congressional districts in their favor.

That projection — outlined in a new report from Fair Fight Action and the Black Voters Matter Fund and shared exclusively with POLITICO — suggests that striking down Section 2 of the Voting Rights Act could all but ensure continued Republican control of the House of Representatives.

While a ruling before next year’s midterm elections remains uncertain, the organizations behind the report said it is still possible. In total, the groups identified 27 congressional seats nationwide that could be redrawn to favor Republicans if current legal and political conditions hold — with 19 of those shifts directly tied to the potential elimination of Section 2 protections.