The brief is submitted by the leadership of both the House and Senate Democratic caucuses, along with the co-chairs of the House LGBT Equality Caucus, on behalf of 212 Democratic members of Congress. That includes 25 members who voted for DOMA back in 1996. These members wanted the court to "hear the full story from Congress, and to explain why they believe that Section 3 of DOMA is unconstitutional," and to inform the court that while the House majority Republicans have continued the defense of the case, the entire Congress is not in agreement. They argue:
When Congress enacted DOMA, gay and lesbian couples could not marry anywhere in the world. Some States still criminalized same-sex relationships, inviting further discrimination against gay men and lesbians in employment, family relations, and housing. Gay men and lesbians were still often portrayed as mentally unstable, sexually promiscuous, and morally deficient. In short, it was a different world for gay men and lesbians, and many were understandably reluctant to speak openly about themselves or their families. A number of Members, like the constituents we serve, did not personally know many (if any) people who were openly gay, and majority attitudes toward that minority group were often viscerally fearful and negative.
As a result, when the question of same-sex marriage arose in 1996, reflexive beliefs and discomfort about same-sex relationships dominated congressional debate. From our perspective—including those of us who voted for DOMA—debate and passage of the law did not necessarily arise “from malice or hostile animus,” but instead from “insensitivity caused by simple want of careful, rational reflection or from some instinctive mechanism to guard against people who appear to be different in some respects from ourselves.”
They argue that Section 3 of DOMA, the provision that same-sex marriages will not be recognized by the federal government for all federal purposes,(insurance benefits for government employees, Social Security survivors' benefits, immigration, and the filing of joint tax returns) is "a violation of the Fifth Amendment’s equal protection guarantee and should be struck down." Eight federal courts have agreed.