Others, however, used stronger language. Then-congressmen Tom Coburn, R-Okla., said his district "has very profound beliefs that homosexuality is wrong." He said his constituents believe "that homosexuality is immoral, that it is based on perversion, that it is based on lust. It is not to say that the individual is any less valuable than anybody that might believe that, but it is discrimination towards the act, not towards the individuals."
Perhaps some of the most critical language came from a Democrat, Sen. Robert Byrd of West Virginia.
"That we have arrived at a point where the Congress of the United States must actually reaffirm in the statute books something as simple as the definition of 'marriage' and 'spouse' is almost beyond my grasp," he said.
And then, "to insist that male-male or female-female relationships must have the same status as the marriage relationship is more than unwise. It is absurd. Out of such relationships children do not result."
Byrd was 79 at the time.
EVOLUTION OF BELIEFS
In 1996, only 67 members of the House and 14 senators voted against DOMA. Prominent Democrats who voted for DOMA included Joe Biden, Tom Daschle, Joe Lieberman and Harry Reid.
But some changed their minds over time.
One of those was Rep. Steny Hoyer, D-Md., who now serves as Democratic Whip. In a statement released in May, Hoyer said his thinking has evolved and he now believes "that extending the definition of marriage to committed relationships between two people, irrespective of their sex, is the right thing to do."
GLAD's Wu says an evolution occurred in many cases because there were no gay married couples in the country at the time of the DOMA debate. "Seeing the reality of gay married couples and their children is profoundly important in helping the public and our legislators see the importance of protecting all families," he says.
President Obama told ABC's Robin Roberts in May that he, too, had changed his thinking and now personally supports same-sex marriage. (Many say his hand was forced by Biden's implying on a Sunday morning talk show that he was "comfortable" with same-sex marriage.)
But even before the president made that determination, he had directed his Justice Department to stop defending DOMA in court, believing that the issue belonged to the states.
As such, House Republican leaders tapped lawyer Paul Clement to defend the law.
Edward Whelan, president of the conservative Ethics and Public Policy Center, is careful to separate the legal debate regarding DOMA from the change in public opinion.
"The constitutional status of DOMA shouldn't be affected at all by any change in public opinion on same-sex marriage," the DOMA supporter says. "Supporters of same-sex marriage are free to try to revise DOMA legislatively."
Regarding some of the comments made by legislators during the floor debate in 1996, he says, "Under ordinary rational-basis review, the cherry-picked comments of particular legislators are irrelevant. What matters are the conceivable justifications for the law."
Whelan points out that Clement has stressed in his briefs defending DOMA that the federal interest in uniform eligibility for federal benefits is clearly sufficient to justify the law.
"There are 41 states that retain the traditional definition of marriage," Whelan says. "The Constitution doesn't require taxpayers in those states to subsidize same-sex marriage."
As for Barr, the Georgian left Congress and ran as a libertarian candidate for president in 2008.
"I have made mistakes," he told an audience.
He said he had changed his position and that DOMA should be struck down on federalism grounds:
"The Defense of Marriage Act, in so far as it provided the federal government a club to club down the rights of law-abiding American citizens, has been abused, misused, and should be repealed."