Mayer Brown, a leading global law firm, filed a historic amicus brief today on behalf of 172 Members of the US House of Representatives and 40 US Senators, in United States v. Edith Schlain Windsor, a landmark challenge to Section 3 of the 1996 Defense of Marriage Act (DOMA) before the US Supreme Court. Section 3 of DOMA defines marriage for purposes of federal law as “only a legal union between one man and one woman,” excluding legally married same-sex couples from all marriage-based federal responsibilities and rights.

In the brief Mayer Brown filed today, the participating Members of Congress said they decided to participate as amici in this case because they wanted to dispel the notion that the Bipartisan Legal Advisory Group (BLAG), a standing body of the House of Representatives that intervened in the case to defend DOMA, speaks for all of Congress and to explain why they believe that Section 3 of DOMA is unconstitutional.

The brief states that times have changed and attitudes have shifted since DOMA was enacted, and it is clear that DOMA “lacks the required rational connection to a legitimate federal interest: ‘It is a status-based enactment divorced from any factual context.’”

The brief argues that DOMA does not rationally serve Congress’s legitimate interests in the welfare of American families. “Gay and lesbian couples can now marry in nine states and the District of Columbia, and 18,000 such couples remain legally married in California as well.” Members believe that Section 3 of DOMA is a violation of the Fifth Amendment’s equal-protection guarantee and should be struck down.

Mayer Brown attorneys who drafted the brief include Supreme Court & Appellate group partner Miriam Nemetz, counsel Richard Katskee and associate Michael Kimberly (all in the firm’s Washington, DC office).

Mayer Brown’s more than 45 appellate lawyers have argued over 220 cases before the US Supreme Court, representing either parties or amici in approximately 15 cases each term for the past several years.