The U.S. Supreme Court on Monday ruled that states can require electors to vote for the winner of the state’s popular vote for president in the Electoral College. In the unanimous decision based on a Colorado case, Justice Elena Kagan wrote that nothing in the U.S. Constitution prevents states from punishing so-called faithless electors — members of the Electoral College who do not vote in accordance with the people of their state. The decision comes four months before the next presidential election. Colorado’s case concerned several electors who tried to vote for Republican John Kasich instead of Hillary Clinton — the state’s winner — in 2016 in an effort to keep Donald Trump from becoming president.