WASHINGTON – Conservative Supreme Court justices appeared poised Monday to strike down a San Francisco law school’s refusal to recognize a Christian student group because it effectively prohibits gays from joining.

With pointed questions and sharp tones, the court’s most vocal conservatives repeatedly challenged the University of California’s Hastings College of the Law’s treatment of the Christian Legal Society. The skeptics say the school violates the organization’s First Amendment rights to define their own membership.

“It is so weird to require the campus Republican club to admit Democrats,” Justice Antonin Scalia said, using an analogy. “To require the Christian society to allow atheists not just to join, but to conduct Bible classes, that’s crazy.”

Chief Justice John Roberts and Justice Samuel Alito voiced similar sentiments.

In a sign that the closely watched freedom-of-religion case is heading for a split decision, however, Justices Ruth Bader Ginsburg and Sonia Sotomayor questioned whether another group might ban women or minorities under the Christian group’s reasoning.

“What is wrong with the purpose of a school to say, ‘We don’t wish (to recognize) any group that discriminates?’ ” Sotomayor asked.

Justice John Paul Stevens echoed the point by asking about a hypothetical student group whose “belief is that African-Americans are inferior.”

Stanford Law School professor Michael McConnell, the attorney for the Christian Legal Society, replied that a student organization could be allowed to require members to hold racist beliefs but couldn’t be allowed to restrict membership based on an applicant’s racial status.

“You can have a student organization, I suppose, of that type,” Scalia offered, but “it wouldn’t include many people.”

Hastings currently recognizes about 60 student organizations, from the Hastings Student Animal Legal Defense Fund and the Association of Muslim Law Students to the Hastings Democratic Caucus. The school doesn’t recognize the Christian Legal Society.