The U.S. Supreme Court canceled a scheduled showdown over the bathroom rights of transgender students in public schools, sending the case back to a lower court after the Trump administration changed a pivotal federal policy (Gloucester County School Board v. G. G., U.S., No. 16-273, vacated and remanded 3/6/17).

The justices were planning to hear arguments March 28 in the case of Gavin Grimm, a transgender Virginia high school student suing his school district to get access to...