Where'd all my backup go? Hmm.... deserters.
Anyway, still not much time, but I'll give you what I've got.
As I've said, I don't have a problem with gays/lesbians choosing that lifestyle. It's their business, and while I think it's wrong and is sin, it's their decision. However! Marriage is a different issue entirely. I'm going to go look up the surveys I was talking about literally right now, but the point I was getting at is that most of the proponents of gay marriage are more against the traditional family than for gay marriage.
Skin - I think it was you who pointed out about the nuclear family being recent and western. True. But the rest of the family's involvement has nearly always been in conjunction with the heterosexual marriage - even in primitive cultures.
Next - question: if homosexual commitments can be defined as marriage, what's wrong with polygamy? Sodomy? Incest? I know I'm going to get slammed for this, but there is literally no difference: if it's between consenting adults, it should be fine (and acceptable for marriage), according to this forum and many Deomocratic leaders. Now, I'm off to find a study!