By now, of course, the idea that same-sex couples should have the same freedom to marry as interracial couples has become a favorite gay-rights trump card. So has the view that opponents of gay marriage occupy the same moral and legal swamp as the segregationists who thought Mildred and Richard Loving's marriage should be a crime. Today those who insist that society retain the timeless definition of marriage as the union of male and female can expect to be excoriated as bigots and haters, and to be assured that history will revile them just as it reviles Bull Connor and Lester Maddox.
I'm not so sure.
There is no disputing the emotional power of linking the campaign for gay marriage today to the struggle over anti-miscegenation laws in the Civil Rights era. I agree that the two are connected. But not in the way same-sex marriage advocates think.
When the Supreme Court ruled in June 1967 that Virginia's law penalizing interracial marriage could not stand, it was not changing the fundamental and enduring meaning of marriage: It was affirming it. It was upholding the integrity of marriage by protecting it from irrelevant -- and unconstitutional -- racial manipulation. Virginia had interfered with the core elements of marriage in order to promote white supremacy, a value completely alien to marriage. Marriage is designed to bring men and women together; anti-miscegenation laws frustrated that design, and could not stand.
Same-sex marriage, too, interferes with the core elements of wedlock in order to advance an unrelated goal -- the dignity and equality of gays and lesbians. The fact that many decent people ardently embrace that goal doesn't change reality: The essential, public purpose of marriage is to unite male and female -- to bind men and women to each other and to the children that their sexual behavior may produce. It is rooted in the conviction that every child needs a mother and a father. Gay marriage, whether enacted by lawmakers or imposed by judges, disconnects marriage from its most basic idea. Ultimately, that isn't tenable either.
The old laws banning interracial marriage had a long run but they eventually collapsed. The new laws in New York and other states authorizing same-sex marriage may be destined for a long run as well, but I suspect they too will eventually collapse. Marriage -- male-female marriage -- is indispensable to human welfare. That is why it has existed in virtually every known human society. And why it cannot, and will not, be permanently redefined.
Jeff Jacoby is a columnist for The Boston Globe.