Andy Kropa / Getty Images Edie Windsor

A federal law that leaves hundreds of thousands of same-sex couples without any recognition of their marriage violates the Constitution, lawyers for a woman whose wife’s death left her unprotected from more than $350,000 in estate taxes said in a legal brief Tuesday, one month before the Supreme Court hears her case.

The landmark case is one of two the court will hear in March about the battle over whether same-sex couples can legally wed, and if they do, whether they can receive spousal benefits and get the same rights that heterosexual couples currently enjoy.

The former is a legal fight over California’s Proposition 8, which bans gay marriage, and the latter centers on Section 3 of the Defense of Marriage Act, which bars recognition of same-sex marriage at the federal level.

Of a few cases brought to the high court challenging DOMA, the justices chose to hear the one brought by Edie Windsor, whose wife, Thea Spyer, died in 2009. The New York couple married in 2007 in Canada, though they were together for 44 years before Spyer died.

Spyer left her estate to Windsor. As a married heterosexual couple there would have been no estate tax. But Windsor was left with a federal tax bill of $363,000 since the couple’s marriage was not recognized by the U.S. government.

The lawyers’ brief filed Tuesday by Windsor’s lawyers argues that DOMA's Section 3, which defines marriage at the federal level, “violates the Constitution because it treats married gay couples differently than married straight couples” for “no logical reason,” the American Civil Liberties Union, part of Windsor's legal team, said in a summary of the brief.

Gays and lesbians, who have already endured a long history of discrimination, the ACLU said, were subjected to further discrimination from DOMA, which they noted Congress passed in 1996 “based on fear of and stereotypes about gay people, rather than any legitimate government purpose.”

“But the Constitution doesn’t permit the government to pass a law just to disadvantage a politically unpopular group of people,” the group added.

DOMA affects more than 1,100 provisions of federal laws, denying gay couples the right to file joint taxes, the protections of the Family Medical and Leave Act, and blocks surviving spouses from accessing veterans’ benefits, among other things, Windsor’s lawyers said.

“DOMA excludes married couples who are gay from all of the rights, privileges and obligations that the federal government otherwise affords married couples,” her lawyers’ brief said.

Two lower courts have agreed with Windsor and her attorneys. Other lower courts that reviewed DOMA challenges elsewhere, such as in Boston, reached similar findings.

The Obama administration filed a brief last Friday in the case with the Supreme Court asking it to throw out Section 3, which it had already stopped defending.

The administration also mentioned California's Proposition 8 and similar measures in other states as evidence that anti-gay discrimination remained a major problem.

The appeal of the lower courts’ decision was brought by the Bipartisan Legal Advisory Group, a congressional group made of three Republicans, including House Speaker John Boehner, and two Democrats.

In its brief, filed in late January, the group argued to let the debate over same-sex marriage continue to play out as it has been through votes in many states and public debate, saying “gays and lesbians have substantial political power, and that power is growing. Victories at the ballot box that would have been unthinkable a decade ago have become routine,” it said, apparently referring to wins for same-sex marriage in four states last November.

“There is absolutely no reason to think that gays and lesbians are shut out of the political process to a degree that would justify judicial intervention on an issue as divisive and fastmoving as same-sex marriage,” the group said, as it urged the court not to step in.

“Indeed, the democratic process has substantial advantages over constitutionalizing this issue. Same-sex marriage is being actively debated in legislatures, in the press, and at every level of government and society across the country. That is how it should be,” the group added.

The court will hear on DOMA from both sides on March 27, one day after Proposition 8 supporters and opponents go before the justices.

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