Gloucester County School Board filed its petition with the Supreme Court to hear its appeal of the Fourth Circuit ruling in favor of Gavin Grimm (G.G. in court documents) on Monday.

Gloucester argues that it should not have to accommodate transgender students, but much of the petition focuses on an important question about when courts should defer to an agency’s interpretation of its own regulation. The Court’s three most conservative members recently expressed interest in increasing the power of the judiciary at the expense of federal agencies, and it is possible that the Court could take up this issue if they can secure a fourth vote.