It used to be thought that women had no business voting. But when women got the vote, men didn't suddenly decide their once-exclusive prerogative was worthless. Blacks were once barred from owning property. When the laws changed, whites didn't suddenly give up buying in favor of renting.
Admitting an excluded group to an institution doesn't necessarily weaken the institution. When the subject is matrimony, however, self-styled defenders of marriage say that if it isn't restricted, it will promptly wither and die. They think allowing gays to wed would soon cause heterosexuals to abandon marriage, start propagating offspring out of wedlock and slide into degeneracy.
American treatment of homosexuality has come a long way. Though many people view it as a sin, it's no longer a crime. Gays and lesbians can now live their lives openly.
Changes like these were unimaginable 50 years ago, but they haven't led to a collapse of the social order. Yet we are told that allowing homosexuals to join in legally sanctioned unions will reduce Western civilization to a smoking ruin.
That's one of the chief rationales for efforts to block same-sex marriage. On Tuesday, eight states are offering ballot initiatives against it, and most, if not all, are expected to pass.
Supporters of these bans warn that redefining marriage to include same-sex couples would damage it beyond repair. Maggie Gallagher, head of the Institute for Marriage and Public Policy, writes that gay marriage would grossly shortchange the needs of children "in order to further adult interests in sexual freedom."
Now, it will come as a shock to heterosexual couples that marriage can further sexual freedom. But never mind that. As it happens, sodomy laws have been struck down by the Supreme Court. Gays are already at liberty to have commitment-free trysts with members of Congress, evangelical pastors and anyone else they choose. Unfettered sex is already abundantly available to gays who want it.
What same-sex marriage offers, by contrast, is a safe harbor for those who prefer responsible monogamy to free love. It's not a rejection of the values of traditional marriage -- it's an affirmation.
Gallagher and others say conventional marriage serves to reconcile "the erotic, social, sexual and financial needs of men and women with the needs of their partner and their children." Funny -- that's also what gay marriage does. It provides a durable framework in which two people can commit themselves to an exclusive sexual relationship while assuring a stable environment for their children.