But the argument is whether same-sex marriage should be legal, not whether it should be ordained by God. If you want to believe that God doesn't recognize the same-sex marriage, that's fine. But at least let the government recognize it.
You guys (maybe not you, but those Christians against) are voting it down because you think God disapproves. How do you expect people to see the love of Christ in you when you're denying them these secular, human, legal rights? Jesus Christ never, ever claimed he wanted a seat in the government. He concerned himself with spiritual matters and left the laws of the land up to us.