The federal statutes outlawing employment discrimination based on race, sex, age and disability contain no express exception for church employers. But for 40 years lower courts have applied a “ministerial exception,” which bars the government from any role in deciding who should be a minister. Courts have reasoned that the separation between church and state protects the ability of churches to choose their own clergy just as it protects the state from any control by churches. The Supreme Court has never spoken to the issue.

But who counts as a minister? Cheryl Perich’s duties included leading students in prayer and worship, but she also taught secular subjects, using ordinary secular textbooks. The sole disagreement in the lower courts was whether her job was sufficiently religious to be considered ministerial. The Supreme Court will consider, for the first time, how to make that determination.

But the Obama Justice Department has now asked the court to disavow the ministerial exception altogether. This would mean that, in every future case, a court—and not the church—would decide whether the church’s reasons for firing or not hiring a minister were good enough.