The Voting Rights Act over its six decades became one of the most consequential laws in the nation’s history, preventing discrimination against minorities at the ballot box and helping to elect thousands of Black and Hispanic representatives at all levels of government.

Alabama Governor Kay Ivey has called for a special session centered on redistricting following the Supreme Court’s landmark Callais decision earlier this week.

They invited Republican state legislatures to draw new congressional maps that will probably create a solid red south, the largest reduction in Black political representation since the death of Recons...