The Supreme Court ruled that Arizona’s voter-ID law, which required would-be voters to prove their citizenship, is illegal under federal law. Writing for the majority, Justice Scalia decided that Arizona’s law was preempted by the federal National Voter Registration Act. The court also ruled that facts that increase mandatory minimum sentences must be proved to the jury, not just a judge. But the justices deferred several highly anticipated decisions, including ones on same-sex marriage, affirmative action, and the Voting Rights Act. They’ll announce more decisions this Thursday.