Updated at 2 p.m.

The U.S. Supreme Court, expanding the reach of the federal law banning age discrimination in the workplace, unanimously ruled Tuesday that state and local political subdivisions of any size must comply.

Justice Ruth Bader Ginsburg wrote the first opinion of the term in Mount Lemmon Fire District v. Guido, argued just five weeks ago. Justice Brett Kavanaugh did not participate in the case, which was argued on the term's first day—Oct. 1. He was not sworn into office until Oct. 5.