Shelby County v. Holder
In Shelby County v. Holder (2013), the U.S. Supreme Court invalidated preclearance requirements for elections that had been obstacles for decades in certain states under Section 4 Voting Rights Act of 1965. They had been required to obtain approval by the Department of Justice before changing their election laws.
The Supreme Court held that the coverage formula in Section 4(b) was based on stale data and was unconstitutional in how it distinguished among the States, and thus it "can no longer be used as a basis for subjecting jurisdictions to preclearance." 133 S. Ct. 2612, 2631 (2013).