McCain led the fight on the Senate floor against the Marriage Amendment.
McCain just didn't think the constitution was the vehicle for opposing gay marriage--a lot of conservatives have taken that position. I think he has a point. The constitution has never been used to deny rights or privileges. I'm not comfortable with doing it now though I oppose gay marriage. It should be left to the states to decide--isn't that the conservative position? And so far nearly all the states have gotten it right. But McCain has made clear he opposes gay marriage. He's stated it over and over. He's also remaining steadfast in opposing gays in the military.