The National Collegiate Athletic Association (NCAA) has gotten ahead of its member universities and its own constitutional principles. On Sept. 12, the association pulled all 2016-17 national-championship events out of North Carolina to protest a state law there overriding local antidiscrimination ordinances that, among other things, allowed transgender people to use the public restroom of their choice.

House Bill 2 (H.B. 2) requires that “multiple occupancy bathroom or changing facilities” in public schools or maintained...