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 restrooms that align with his gender identity.

Both sides had urged the court to keep the case, with the school...