The court decision that overturned California Proposition 8 supports the American foundation of equal legal protection and could also be applied to future questions about freedom of religion and freedom FROM religion.
Moral disapproval alone is an improper basis on which to deny rights to gay men and lesbians. The evidence shows conclusively that Proposition 8 enacts, without reason, a private moral view that same-sex couples are inferior to opposite-sex couples. (pp 135 line 3)
The key part is “Moral disapproval alone is an improper basis on which to deny rights…”
It remains to be seen if that would actually work but it would be something to try in a future complaint or law suit over religious freedom issues.
Another important point is that civil rights are not open to a popularity contest and never should be.