One Supreme Court justice was not present for Wednesday's heated arguments over a bid by the Catholic Church to create the nation's first religious charter school.
Justice Amy Coney Barrett recused herself from the case.
Although she didn't give a reason, Barrett is close friends with the Notre Dame Law School professor who was an early legal adviser to the Catholic Church in Oklahoma.
Her absence means the court could deadlock 4-4 on a decision. If they do, that would leave in place the Oklahoma Supreme Court's decision that religious charter schools are not allowed.
Barrett is one of the six practicing Catholics on the court. (Justice Neil Gorsuch was raised Catholic but is Episcopalian.)