The U.S. Supreme Court on Wednesday declined to let South Carolina enforce a law requiring public schools to bar transgender students from using restrooms aligned with their gender identity, leaving in place a lower court’s injunction that protects a 15-year-old boy in Berkeley County. In a terse, unsigned order, the justices, by an apparent 6-3 vote, rejected the state’s request for emergency relief, stressing that the denial was “not a ruling on the merits” of the case but instead r...