Over at Crooked Timber, Kieran Healy heroically tries to engage the arguments of a same-sex marriage opponent. Personally, I find that taking on these arguments is a complete waste of time since they are offered in obvious bad faith. Opponents of same sex marriage talk a lot about family and procreation, but offer solutions which are aimed entirely exclusively at behavior the bible frowns upon. Obviously, they have a not-so-hidden agenda. They love to say that marriage is about procreation (which I suspect will come as a surprise to most of the people getting married today), but they make no effort to prevent infertile couples or asexuals from getting married. Nor do they seek to forbid marriage among couples who do not plan on raising children.
It is sometimes tempting to respond to gay marriage opponents because their arguments are so obviously ridiculous - anyone who maintains that marriage is about procreation must not have seen a romantic comedy at the movies for 40 or 50 years. While I am glad that someone is trying to make these people see the error of their ways, I think its safe to say by now that the matter is settled on an intellectual level: there simply aren't any intellectually respectable arguments for the anti-gay marriage policies pursued by conservatives today.