The U.S. Supreme Court issued a landmark decision that severely restricts the use of racial data when drawing electoral districts. The ruling could significantly reshape congressional maps across the nation, impacting upcoming election cycles.

The US Supreme Court on Wednesday sharply limited the use of race in drawing electoral districts, in a decision that could reshape congressional maps nationwide and boost Republican prospects ahead of midterm elections. In a 6-3 ruling split along ideological lines, the conservative-dominated court struck down a map that creates a second majority-black district in Louisiana, finding it amounted to an unconstitutional racial gerrymander despite being drawn to comply with the 1965 Voting Rights...