Eric O'Keefe v. John Chisholm

EASTERBROOK, Circuit Judge.

A federal district judge issued an injunction that blocks the State of Wisconsin from conducting a judicially supervised criminal investigation into the question whether certain persons have violated the state’s campaign-finance laws. The court did this despite 28 U.S.C. § 2283, the Anti-Injunction Act, which provides: “A court of the United States may not grant an injunction to stay proceedings in a State court except as expressly authorized by Act of Congress, or where necessary in aid of its jurisdiction, or to protect or effectuate its judgments.” Mitchum v.…