All other things being equal, which of course is never the case, isn't a kid living with two parents, one male, and one female, probably the most ideal for the kid - you know gender role models and so forth? As others have stated, just because something is best, does not mean that some law should mandate it (among other things, as I said, all other things are really never equal). The elusive theoretical perfect can be the enemy of the practical good.
Not really. My parents had a very ugly marriage. My quality of life improved immensly when they got divorced. And I don't think I'm alone in saying I'm tired of santimonious Republican politicians telling me what my family is supposed to look like. For a party that claims to be for "small gov't" they're strangely obsessive about what people do in their own homes on their own time.
