Rebutting Gay Marriage Opponents

From Time:
"Arguments against gay marriage tend to fall into three broad categories: it is a threat to tradition (the idea is historically not sanctioned; the bible does not approve); it is a threat to children (kids will learn about homosexuality in school, confuse gender roles, or even become gay themselves); and it is a threat to heterosexual marriage (the straight family structure will collapse).

The first argument, tradition, is the one closest to faith. It is not subject to much debate. If one believes that God condemns homosexuality, then that's what one believes, no matter what the American Psychological Association says. But precisely because this argument is so personal, and so religious, it is the least used by opponents of gay marriage in public debate. You don't see many quotes from Leviticus being read on the Senate floor.

The second argument, children, tends to only show up at the most heated political moments, often with devastating effect. During the Proposition 8 campaign in California, opponents of gay marriage repeatedly evoked innocent children in their advertising campaign. The campaign claimed that a state constitutional amendment to ban men from marrying men, and women from marrying women, had "everything to do with schools." This is an indirect argument, of course. No one has proposed teaching second graders about homosexuality. But if the state officially sanctions gay unions, the notion that gay unions are not an abomination (see tradition) is certain to filter down. The secondary argument, about gay parents and gender roles, meanwhile, is based on an unfounded fear, at least according to scientists at the American Psychological Association. There is no evidence that children of same-sex parents are worse off, nor is there evidence children of same-sex parents are more likely to become gay.

The third argument, that gay marriage threatens straight marriage, is the most prominent in the public debate. Outspoken opponents of gay marriage, like Kansas Sen. Sam Brownback, can expand at length about Nordic marriage trends, where gay unions are not so frowned upon. This argument follows from the idea that marriage is a singular societal institution that is instrumental in keeping straight couples together. If the definition of the institution changed, goes the argument, then straight couples would be less likely to think marriage is important, and therefore less likely to stay together for the sake of their children. As President Bush likes to say, "Changing the definition of marriage would undermine the family structure."
As a straight guy who grew up in San Francisco, where gay culture is ubiquitous, I have never felt the tug of this argument. Why would the gay couple next door make me less interested in monogamy, my fidelity to a woman I loved, or my desire to provide a stable family structure for my children?..."
http://swampland.blogs.time.com/2008/11/26/feminism-and-the-3-arguments-against-gay-marriage/