No one thinks that a marriage or a wedding is just a license. Not performing a wedding ceremony(license or not) for Gay people is contrary to public policy and discriminatory, by definition. For a truly private institution or individual there is likely no legal recourse. Haters gunna hate. IF, on the other hand, you are a non profit than your policies must be nondiscriminatory falling in line with public policy and the constitution.
From the Supreme Court Hearing on Gay Marriage
-During oral arguments in March, Justice Samuel Alito compared the case to that of Bob Jones University, a fundamentalist Christian university in South Carolina. The Supreme Court ruled in 1983 the school was not entitled to a tax-exempt status if it barred interracial marriage.
Solicitor General Donald B. Verrilli Jr., arguing for the same-sex couples on behalf of the Obama administration, said,”You know, **I don’t think I can answer that question without knowing more specifics, but it’s certainly going to be an issue. I don’t deny that. I don’t deny that, Justice Alito. It is –it is going to be an issue.”-
No, the government cannot force churches to perform ceremonies but it can revoke tax exempt status if they don't. In the Bob Jones case they are discussing above the University lost its tax exempt status not for refusing to sign a marriage license, not even for refusing to perform the ceremony but for not admitting people who where in a mixed race marriage.
If a tax exempt org discriminates against people in a legal union they could lose their exempt status even if they had nothing to do with the ceremony or signing the license. So taking the signing of marriage licenses out of the hands of clergy or whatever does not resolve the issue. The IRS will have to act. Which eventually they will. Then it will have to go before the court and I would think that there is a fair probability that they will uphold revoking that tax exempt status.
