In a 5 to 4 decision, the U.S. Supreme Court struck down Section 4 of the Voting Rights Act of 1965, a key provision that requires certain states to get federal pre-clearance in order to change any voting-related laws. The Court has held that the criteria used for pre-clearance has become antiquated.
The plaintiff in the case was Shelby County, Alabama.
SCOTUS Guts the Voting Rights Act of 1965
ABC News: Article on the SCOTUS decision on Section 4 of the Voting Rights Act of 1965