A new case is underway in the ongoing and escalating conflict between laws protecting religious freedom and laws prohibiting sexual orientation discrimination. And this one has the potential to either strengthen or cripple laws that prohibit discrimination based on sexual orientation across the nation.

The case, Matthew Barrett v. Fontbonne Academy, has been brought by Gay & Lesbian Advocates & Defenders (GLAD), the organization that won the right to marry for same-sex couples in Massachusetts. GLAD also led the way to strike down the federal Defense of Marriage Act (DOMA) and state bans on marriage for same-sex couples in all 50 states.

Barrett is one of many cases around the country that are testing the right of various employers to circumvent laws prohibiting discrimination based on sexual orientation. In most of these cases, the lawsuits have been filed against employers who claim their discrimination is a necessary part of their free exercise of religion. And in most, the conflict has been played out between individual businesses in the public realm –bakers, florists, wedding vendors— refusing service to same-sex couples getting married.

In this case, however, the employer also claims a First Amendment right to “expressive association,” an argument that could have far-reaching implications.

“The expressive association argument could be used by non-religiously affiliated institutions” to justify discrimination based on sex or sexual orientation, explained Bennett Klein, a long-time attorney for GLAD. Klein is representing Matthew Barrett, who lost his new job with Fontbonne Academy in Massachusetts after he filled out some paperwork indicating that, in an emergency, his employer should contact his husband, Ed Suplee.

Fontbonne, a Catholic-affiliated secondary school for girls, had hired Barrett to be its director of food services. The school’s student population includes non-Catholics, and the food services director has no explicit duties to instruct any of the students in religious tenets.

But at a preliminary argument December 1, an attorney for Fontbonne, John Bagley, said Barrett’s being married to a man would interfere with the school’s Catholic-oriented message.

“How can [the school] credibly talk to kids about the Catholic faith if somebody who’s an employee is involved in activity inconsistent with the message of the school?” said Bagley. As an example, he noted that, if Barrett and his spouse show up at a school-wide party or event, the students might assume the school is conveying an implicit message that same-sex marriage is acceptable to the church.

To buttress his argument, Bagley pointed to the 1995 U.S. Supreme Court decision in the St. Patrick’s Day parade lawsuit, Hurley v. Irish-American Gay. That decision held the right to expressive association permitted the private organizers of Boston’s annual parade to bar a gay group from participating in the parade behind a banner which identifyied them as gay. Bagley’s brief also argued that a 2000 Supreme Court decision in Boy Scouts v. Dale held that a private organization had an expressive association right to bar a gay man from a leadership position in the group.

Klein argued December 1 that Barrett, by being married to a man, is not attempting to convey a message, like the Irish-Gay parade contingent, and that Barrett is not assuming a role as advocate, as gay scout leader James Dale did.

“Sexual orientation is not a message, and there’s no distinction between sexual orientation and being married to a person of the same sex,” said Klein in court. Fontbonne’s decision to withdraw its job offer “was based on [Barrett’s] status …not based on him doing anything [or] saying anything.”

Neither of Fontbonne’s attorneys, John Bagley nor Jeffrey O’Connor, were available to take this reporter’s call, and Bagley begged off reporters’ questions following the hearing.

Bagley also argued December 1 that he believes there are some facts in dispute. If Norfolk County Superior Court Judge Douglas Wilkins agrees, he could schedule the matter for a jury trial. If he disagrees, he could rule on the merits of the case. Whenever the lawsuit is resolved, it will almost certainly be appealed to the Massachusetts Supreme Judicial Court and, eventually, the U.S. Supreme Court.

GLAD founder John Ward, who argued the Hurley case in the Supreme Court, said he considers the Fontbonne case to be “hugely important” because, for gay people, “the issue around the country is: You can get married on Sunday and fired on Monday.”

Ward said he thinks this case could help decide the current conflict over the use of religion to justify discrimination based on sexual orientation.

“There’s been this trend in U.S. Supreme Court cases that hasn’t been real helpful,” said Ward, referring to recent decisions. Last year, in Burwell v. Hobby Lobby, the high court ruled that a federal law can not require a closely held commercial employer to provide health insurance coverage for contraception if that employer claims that to do so violates his or her personal religious beliefs. Prior to that, in Hosanna-Tabor v. EEOC, the Supreme Court ruled that the First Amendment bars lawsuits on behalf of “ministers” against their “churches,” holding that it is “impermissible for the government to contradict a church’s determination of who can act as its ministers.”