In a rare unanimous decision, the Supreme Court ruled on Wednesday that the Eighth Amendment’s ban on excessive fines applies to state and local governments. In her decision, Justice Ruth Bader Ginsburg quotes the Magna Carta to demonstrate that for hundreds of years, society has recognized that fines must “be proportion[ate] to the wrong” and “not so large as to deprive [an offender] of his livelihood.” She cites William Blackstone (the leading 18th-century English commentator on the law) to suggest that in order to determine excessiveness of fines, the court must consider a person’s wealth. Finally, citing a decision by the late Justice Antonin Scalia (as well as the amicus brief we filed in support of the petitioner, Tyson Timbs), Ginsburg suggests there is a particular risk of excessiveness when government imposes fines in order to raise revenue.