Last week, President Obama’s Justice Department asked the Supreme Court to hear oral arguments in a case that pits religious protections against the courts’ ordinary ability to intervene in a labor dispute to prevent discrimination.

In the early 2000s, Cheryl Perich was a “called teacher” or “commissioned minister” at  Hosanna-Tabor Evangelical Lutheran Church and School in Redford, Mich. As such, she taught religious classes, led students in prayer and incorporated religious teachings into secular subjects like math, science, social studies and art.

But in 2004, she was diagnosed with narcolepsy and became unable to teach the fall semester that year. When she failed to return to school in January 2005, the school hired a replacement teacher. The school wanted to “peacefully release” Perich from her “call,” but Perich demanded she be reinstated — and threatened to sue the school if she wasn’t. It was that threat of a lawsuit — not Perich’s narcolepsy — that led the congregation to “rescind her call” (i.e. fire her). Apparently, it’s against church teaching to take an internal dispute of that sort to the secular courts.

But, now, the Obama DOJ wants the courts to force the Lutheran church and school to reinstate Perich, saying that the school fired Perich in violation of the Americans with Disabilities Act.

Acting Deputy Solicitor General Leondra Kruger told the court, during oral arguments, that the federal government should be able to trump the church on these decisions.

“Their submission is that the hiring and firing decisions with respect to parochial school teachers and with respect to priests is categorically off limits,” said Kruger. “And we think that that is a rule that is insufficiently attentive to the relative public and private interests at stake, interests that this court has repeatedly recognized are important in determining freedom of association claims.”

In other words, in the interest of protecting parochial school teachers from discrimination for disabilities, the courts ought to be able to tell churches they have to retain someone as a minister. Again, the school didn’t fire Perich because she had a “disability”; they rescinded her call because she violated church teaching by threatening to sue. But even supposing Perich’s narcolepsy was the reason she was fired, the school’s decision ought to be protected under the “ministerial exception”:

But the ADA contains the same “ministerial exception” as other civil rights laws, a 40-year-old doctrine that precludes courts from interfering in matters “involving the employment relationship between a religious institution and its ministerial employees.” The idea is that you can’t use civil rights laws to force Catholic churches to hire female priests, or orthodox synagogues to ordain Catholics, without running afoul of the First Amendment.

It’s easy to see, though, why this isn’t so clear-cut:

The courts of appeals have for years struggled with questions about this ministerial exception, ranging from “What is a minister?” to “How the hell should we know what a minister is?” We can agree that the cafeteria lady isn’t a minister. But what about a secular teacher who performs some religious duties?

That’s what makes this a case to watch: The Supreme Court will presumably at last clarify the issue. As Terry Jeffrey of CNSNews.com writes, “What is at stake is the First Amendment and the religious freedom of all Americans.”