I've decided that the right has no sensible arguments against gay marriage. Whenever it mentions it, it reverts to "tradition", or just takes it as an obvious fact that marriage shouldn't be made equal. Of course, if we followed "tradition", we'd still have slavery, and women would be the property of their husbands. So far, no one to the left of the John Birch Society is advocating that. The following is my dissection of common conservative arguments against gay marriage.
Argument #1: Homosexuality is a choice/perversion.
Rebuttal #1: This is an easy one. Science is on our side. And even if it wasn't, why wouldn't heterosexuality be a choice as well?
Argument #2: Homosexual marriage will destroy straight marriage.
Rebuttal #2: Got proof? No, no, you don't. In Scandinavia, straight marriage have actually increased since gay unions have been allowed.
Argument #3: If homosexuals are allowed to marry, people must be allowed to marry goats, relatives, and marry multiple people.
Rebuttal #3: 10% of people are gay. I don't know many people who want to marry their goats, relatives, or want to be polygamists. Besides, marrying goats is impossible, as they cannot consent to it, and marrying relatives harms the children in a straight marriage, and is, to use a term that I personally hate, unnatural: people are genetically predisposed to not be attracted to their family members. For more on this argument, see Dahlia Lithwick's excellent article, "Slippery Slop".
Argument #4: The Bible prohibits homosexuality.
Rebuttal #4: No, no, it really does not. The most commonly cited passages in this argument are Leviticus 18:22, "Thou shall not lie with mankind as with womankind: it is abomination", and Leviticus 20:13, "If a man also lie with mankind as he lieth with a woman, both of them have committed an abomination; they should surely be put to death". Never mind that Leviticus is a book of rules for the Israelites traveling for 40 years from Egypt to Palestine, and thus contains rules that dictate not morality, but what must be done for the Israelites to survive. Thus, sex that does not lead to reproduction is counted here. Also, Leviticus 19:19 bans the sowing of two different types of seeds in one area, the crossbreeding of animals, and the wearing of clothes made from mixed textiles. I don't suppose that James Dobson is campaigning against mixed wool and cotton. The two other Biblical phrasing that are used, the story of Sodom and Gomorrah, and Romans 1:26-27, don't condemn homosexuality either. The former is meant as a condemnation of inhospitality, not of homosexuality. Besides, the homosexuality in the story isn't consensual. The latter speaks of men giving up "natural relations" and lusting for one another. But "natural relations" for gays are with members of the same sex; therefore, the passage condemns going against one's sexual orientation, not homosexuality. And none of this matters in a policy debate, of course, due to the separation of church and state.
Argument #5: Homosexuals molest children, and are terrible parents.
All in all, these are very weak arguments. In most political arguments, the case can be made for either side. That's simply not true with gay marriage.