http://www.theatlantic.com/national/archive/2011/11/the-right-to-be-anti-gay/247790/Private religious universities and even the Boy Scouts of America can discriminate on the basis of religion and sexual orientation, but they're in a shrinking minority
Shorter University apparently has the right to require all its employees to sign a pledge affirming their rejection of homosexuality (along with pre-marital sex and adultery), as gay rights critics of the pledge acknowledge. Shorter is reportedly a private religious school, which means that it's protected by the First Amendment and federal employment law, which explicitly exempts religious institutions from bans on religious discrimination. This exemption is not limited to employees performing religious functions, the Supreme Court ruled unanimously in a 1986 case, holding that the Mormon Church had the right to fire a janitor who worked for 16 years at a Mormon operated gym because he failed to qualify for a "temple recommend" (affirming his eligibility to worship).
In adopting a no gay people need apply policy, Shorter is not alone among conservative sectarian and non-sectarian organizations. Christian campus groups exercise their First Amendment rights by discriminating against gay students (sometimes in rules governing leadership positions). The Boy Scouts of America bars gays and atheists from its ranks. The Supreme Court has not been entirely consistent in its rulings on private associational rights to discriminate: In 2000, it correctly upheld the BSA's right to discriminate against gay men, in violation of state law; then, in 2010, the Court incorrectly held that Christian Legal Society campus groups could be punished, by denials of official recognition, for requiring members to sign anti-gay "statements of faith" in violation of campus anti-discrimination policies. And, while universities gained the right to withhold minimal support from Christian groups that discriminated in accord with their religious convictions, Congress continued to fund the Boy Scouts, of course.
It's virtually impossible to imagine Congress withdrawing support and approval from the Scouts, especially these days, when it's also impossible to imagine Congress enacting a federal law barring secular employment discrimination based on sexual orientation. But it's worth remembering that 15 years ago (it only seems like ancient history,) the Employment Non-Discrimination Act (ENDA) extending workplace protections to gays and lesbians failed in the Senate by only one vote. That same year, 1996, the Defense of Marriage Act passed the House and Senate with strong majorities, which included liberal democrats who voted for ENDA. Now in a reversal of political fortunes, the likelihood of DOMA being overturned in federal court seems stronger than the prospect of ENDA being enacted anytime soon.
But in the meantime, prejudices and policies against gays and lesbians in the secular workplace are declining (much faster than prejudices against transgendered people, which will linger). The anti-gay policies of Shorter University and other conservative religious institutions will impose significant hardships on their employees, who might well worry about intrusive efforts to enforce bans on sexual conduct; but these institutions and their homophobic policies are outliers. Watching public opinion and cultural mores shift in favor of gay rights, groups that consider homosexuality sinful seem likely to become increasingly strident and insular, which is good news for the gay rights movement. Let them isolate themselves. Isolation is their prerogative, and -- perhaps it's not unduly optimistic to believe this -- social irrelevance is their fate