The action by Vermont's legislature to legalize gay marriage over the governor's veto is hugely significant. For the first time, it's not a state supreme court doing it, but the people's representatives--and in this case, two-thirds of them.

Vermont is only a small piece of America--the most liberal state, according to a friend of mine who lives there. Vermont is the least religious state, according to a new survey. Vermont, with Maine, has the lowest birth rate of any state. And Vermont's vote for Obama was 68 percent, the highest of any state except Hawaii (72 percent).

Gay marriage now exists in four states in name, and more than that in substance. In all likelihood, people will get used to it, if only because the young get used to it and the young get older. I expect we will have full-fledged same-sex marriage in Washington within the next five years. In Tennessee it will take longer.

The whole subject of gay marriage would have been impossible 30 or 40 years ago. What made it possible, and inevitable, were two things: first, that homosexuals came out of the closet and asked for marriage, using the language of the civil-rights movement; and second, that they began adopting children, and adoption did not turn the kids gay. The idea that people's sexual orientation is hard-wired made adoption acceptable--and if you have adoption, then you have a need for marriage in order to protect children and the partner who looks after the children. And once you have openly gay couples raising kids and doing a good job of it, acceptance follows. Gay marriage becomes not-a-big-deal.

The conservatives who argue that same-sex marriage will lead to polygamous marriage and incestuous marriage (see the reader comments under our news story) are just making loud noises. Incestuous marriage is taboo in all cultures, and will remain so for reasons of family stability and genetics. Polygamous marriage is imaginable, but in our egalitarian culture it would have some problems to work out: If Jim is married to Jane and Joan, and Jane has a baby, is Joan just as much legally the mother as Jane? Polygamous marriage would be much more difficult for Americans (especially feminists) to accept than same-sex marriage, and nobody wants it except religious zanies. You don't need to worry about it.