If conservatives and religious organizations get their way, the exception will grow from a narrow carve-out to a gaping hole in employment law. “It would mean state and federal employment laws largely do not apply to workers for religious businesses,” said Jeffrey Fisher, a professor at Stanford Law School. “Period.”

Much like Fitzgerald, the plaintiffs “were caught rather by surprise to learn that ordinary federal employment law does not apply to them,” said Fisher, who argued the case in front of the Supreme Court. Neither thought of herself as a “steward of the religion,” Fisher said. But in a decision written by Justice Samuel Alito, the court ruled that both were ministers.

The opinion held that the ministerial exception is strictly about “personnel who are essential to the performance” of religious functions, and it was limited to K-12 teachers who actually taught religion. But it “certainly raises the prospect,” Fisher said, that the exception “could be expanded quite a bit by the court.”