Norman Ornstein: In 2024, Louisiana created a new congressional map to remedy racial bias, and the new map created a second majority-Black district. A group of white voters challenged the move as a racial gerrymander, turning the Voting Rights Act on its head. Now, in Louisiana v. Callais, the Supreme Court will decide not just the fate of that district, but whether the part of the Voting Rights Act that forced the redistricting, Section 2, is constitutional.