Supreme Court upholds vote-dilution challenge in Thornburg v. Gingles

The Supreme Court rules in Thornburg v. Gingles on June 30, 1986, interpreting the 1982 amendments to Section 2 of the Voting Rights Act. The case challenges North Carolina legislative districts that weakened Black voters' ability to elect candidates of their choice. The Court sets out a framework for proving racial vote dilution in districting cases, including political cohesion and racially polarized voting. The test becomes central to Section 2 litigation. The ruling gives courts a practical method for judging whether electoral systems dilute minority voting power.