One thing I don't understand about this "traditional marriage"

In the video below, Rick Warren makes a lot of bigoted statements--his comparison of homosexuality with divorce, and incest is just odious. I don't know if there is a special place in hell for people who say these things, but I know there is a special place in history. Anyway the one obvious thing that gets me about his argument is this idea that marriage has, throughout history, been one man and one woman. No it hasn't. That's a fucking lie. Polygamy is ancient. The idea of an old man marrying a child, which Warren raised, is ancient--it's our modern standards that, rightly, condemn the practice. I'm not up on my Bible studies, but isn't there polygamy in the Bible? Beyond that the "appeal to history" argument is particularly disgusting to me as a black person. But by Warren's logic, we should go back to slavery. It is one of the oldest human traditions, no?

Look, I understand the pragmatic politics at work here. I also understand that Obama, perhaps exposing the flaws of pragmatism, doesn't support gay marriage. But watch that video and tell me how that dude is not a bigot. Even a big tent--at the end of the day--must still be a tent. You have to fucking stand for something. Where is all the Good Crazy now?