Regarding gay marriage, really a redefinition of marriage: the ideological lines in American religious communities are pretty much what you would expect. Orthodox Jews are overwhelmingly opposed, Conservative (not a political designation) and Reform Jews are mostly in favor. Seraphic Secret is not as familiar with the multiple and varied Christian communities but we assume the same dividing lines exist with the more liberal churches in favor and the more traditional churches opposed.
But we have not heard much from the usually outspoken American Muslim community. One would assume that pious Muslims would be quite vocal in their opposition for traditional Islam has a clear stance against homosexuality.