Until earlier this week. I was really hoping that this would turn out to be a hoax. No such luck. I've seen it posted, referred to and linked to by enough reliable sources (friends, Boing Boing; even Wikipedia mentions it in their entry on "miscegenation").
So much Fail. He even trots out the old "I'm not a racist. I just don't..." line.
It's "for the children", of course. Because, in his bizarre universe, in-breeding isn't as bad for children as out-breeding is. Because a child of an inter-racial couple might end up growing up and going into politics. And then where would people be?