Editor's note: Paul Waldman is a contributing editor at The American Prospect and the author of "Being Right Is Not Enough: What Progressives Must Learn From Conservative Success." Follow him on his blog and on Twitter.
(CNN) -- You may remember the episode of "Seinfeld" in which George Costanza struggles to find a way to break up with the woman he's dating without hurting her feelings. "It's not you," he tells her. "It's me."
After decades of saying gay people were depraved and deviant, a bunch of dangerous predators out to recruit children and destroy families, in the last few years those opposed to equal rights for gay people have retreated to a very different message. It's not you, they tell gay Americans. It's us.
It's true that you can still find some people on the fringe who will rail against homosexuality as an inherent evil. But watch the mainstream debate, from newspapers to television to the Supreme Court, and what you see are conservatives arguing that the problem isn't gay people themselves, it's how straight people are affected by them.
Opponents of gay marriage want everyone to know that they aren't motivated by bigotry, only by a concern for straight people with tender feelings and fragile marriages.
We saw this at the Supreme Court on Wednesday, when Chief Justice John Roberts tried to argue that the 1996 Defense of Marriage Act wasn't actually motivated by any disapproval of gay people. He seemed incredulous at the very idea when it was brought up by the attorneys seeking to overturn DOMA. "So that was the view of the 84 senators who voted in favor of it and the president who signed it?" he asked repeatedly. "They were motivated by animus?"
The chief justice has a short memory. Back in 1996, those pushing for DOMA were quite forthright about what they thought about gay people. "I come from a district in Oklahoma who has very profound beliefs that homosexuality is wrong," said Tom Coburn, now a U.S. Senator and then a member of the House. "What they believe is, is that homosexuality is immoral, that it is based on perversion, that it is based on lust... We hear about diversity, but we do not hear about perversity." His Oklahoma colleague Steve Largent said, "No culture that has ever embraced homosexuality has survived."
During oral arguments in the DOMA case, Justice Elena Kagan read from a 1996 House Judiciary Committee report on the bill, which said in part, "Civil laws that permit only heterosexual marriage reflect and honor a collective moral judgment about human sexuality. This judgment entails both moral disapproval of homosexuality, and a moral conviction that heterosexuality better comports with traditional (especially Judeo-Christian) morality."
That kind of rhetoric was common in 1996, but you don't hear it coming from members of Congress much anymore.
Why shouldn't gay people be allowed to serve openly in the military? The answer, they say, isn't because gay soldiers, sailors, airmen and marines won't do their jobs well. It's because the straight ones will feel uncomfortable if they have to be in close quarters with gay comrades. It's not about gay service members' performance, it's about the feelings of straight service members (and if you're wondering why we haven't heard too much about the end of "don't ask, don't tell," it's because it turned out that straight military personnel could handle it just fine).
The marriage debate has followed the same course. Opponents of gay rights used to argue that gay people were promiscuous and sexually debauched. But when it turned out that many of them just want to join in stable, permanent family commitments, that argument no longer made much sense. So now opponents say the problem isn't the gay marriages themselves, it's the effect those marriages will have on straight marriages.
What, in particular, will that effect be? Opponents of marriage equality are having difficulty saying, but it seems they believe that if marriage is "devalued" by being open to gay couples, straight people will start ignoring their children, cheating on one another and getting divorced.
Here again, they have retreated to ground that is increasingly difficult to defend. They now argue that the only real purpose of marriage is to rear children biologically related to both parents, a rather pinched definition.
When Justice Kagan asked during oral arguments on Proposition 8 whether, if that was the case, it would be constitutional for a state to ban anyone over 55 from being married, the attorney defending the initiative said no, because marriages between older heterosexuals still foster "the marital norm, which imposes the obligations of fidelity and monogamy," which "make it less likely that either party to that marriage will engage in irresponsible procreative conduct outside of that marriage."
In other words, existing marriage laws discourage people from cheating on their spouses, but if you let gay people get married, the whole country will turn into an episode of "Desperate Housewives," with husbands and wives jumping in and out of their neighbors' beds willy-nilly.
If that sounds ridiculous to you, you're absolutely right. But that's where "It's not you, it's me" eventually leads. If you want to argue that gay rights have to be restricted because of how heterosexuals will react, then you end up saying not only that straight people are frightened of gays and ready to abandon their spouses at the slightest provocation, but that those personal feelings and weaknesses deserve legal protection.
At this point, that's about all opponents of gay rights have left. They don't want to sound like bigots, so they've almost stopped talking about gay people entirely. It's not you, they say, it's us. Well, they're right about that. Just maybe not in the way they think.
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The opinions expressed in this commentary are solely those of Paul Waldman.