Alex Brandon / AP Cardinal Donald Wuerl, Archbishop of Washington, (center) speaks with two nuns in front of the Basilica of the National Shrine of the Immaculate Conception Roman Catholic Church on April 24, 2011 in Washington.

On Wednesday, U.S. Supreme Court Justices heard arguments in Hosanna-Tabor v. EEOC, a case that will give the court its first opportunity to weigh in on an exception that has existed in civil rights law for four decades. The provision, known as the “ministerial exception,” is intended to protect the freedom of religious institutions to designate spiritual leaders and teachers as they choose, not according to anti-discrimination laws (e.g., the government can’t say Catholic churches must hire women as priests).

In the case before the court, a Lutheran school in Michigan hired an instructor to teach mostly secular courses and one class on religious education. She also led a chapel service twice a year. When she refused to resign because of a medical condition that required her to take an extended leave of absence, the school fired her. And when she took her case to the Equal Employment Opportunity Commission (EEOC) on the assumption that she was protected under the Americans with Disabilities Act, the school claimed that she was an employee covered by the “ministerial exception.” The main question before the court then is, who qualifies as a minister? There’s no handy definition that applies across religious traditions. After a morning of questioning made clear the difficulty of a secular court trying to develop religious categories, Justice Stephen Breyer spoke for everyone when he put his head in his hands and said simply, “I’m stuck.”

To the average outside observer, the issues in Hosanna-Tabor v. EEOC seem genuinely thorny, pitting the desire to protect religious freedom against the desire to prevent discrimination. But to many religious conservatives, the case–in which the Justice Department has filed a brief arguing for a narrow definition of the “ministerial exception”–is further evidence of the Obama Administration’s war on religious liberty.

Come again, you say? While you may not have heard much about this charge against the President, you surely will over the next year. Heading into this election season, the U.S. Catholic bishops are making defense of religious liberty their signature issue. Last week, the U.S. Conference of Catholic Bishops launched an Ad Hoc Committee for Religious Liberty to act as a watchdog to combat what the bishops say is an “assault” on religious freedom by the Obama administration. Religious liberty is the only specific issue scheduled for discussion next month at the bishops’ annual meeting. In announcing the formation of this new committee, Archbishop Timothy Dolan of New York said, “Never before have we faced this kind of challenge to our ability to engage in the public square as people of faith and as a service provider. If we do not act now, the consequence will be grave.”

In addition to the Supreme Court case, which the USCCB describes as an “attack on the critically important ‘ministerial exception,'” the bishops identify the administration’s efforts to challenge the constitutionality of the Defense of Marriage Act as a threat to religious liberty. But the issue that has really rallied them against Obama is the proposed HHS rule that would require insurers to cover contraception.

The interim rule includes an exemption for “religious employers,” but the suggested definition for such institutions is extremely narrow and would likely exclude most religious schools, hospitals and service organizations. Some administration officials have suggested that the definition might be broadened–and indeed the rule was published with a call for comment on the much broader definition used by the IRS. But as is, the narrowly-defined exemption has sparked outrage from the USCCB. Not long after the rule was released, the conference’s communications director Sister Mary Ann Walsh wrote, “Health and Human Services must think Catholics and other religious groups are fools.” Richard Doerflinger, who heads up the conference’s pro-life activities, called it the “greatest imposition on religious freedom (and right of conscience) by the federal government” that he’s seen in thirty years.

Despite all the heated rhetoric, at least one longtime observer thinks the uproar about religious liberty is politically motivated. “To a certain extent, we’re seeing a replay of FOCA [the Freedom of Choice Act] here,” he said, referring to the abortion proposal that stoked the anger of pro-life activists during the 2008 election despite the fact that it has never been introduced in Congress. “There’s a lot of political ground to be made by having a campaign even if you’re expecting a different outcome.”

In other words, even if HHS broadens its religious exemption and the court rules against the Obama Administration in Hosanna-Tabor, don’t expect the USCCB to summarily disband the religious liberty committee and make, say, the economy its election-year cause instead.

Amy Sullivan is a contributing writer at TIME, and author of the book The Party Faithful: How and Why Democrats are Closing the God Gap (Scribner, 2008). Articles of Faith, her column on the intersection of religion and politics, appears on TIME.com every Friday.