Judge asked to strike down federal law prohibiting same sex marriages

The plaintiffs are barred from numerous benefits that same-sex couples routinely obtain, including health insurance for federal employees, retirement and survivor benefits under the Social Security Act, and the ability to file joint federal income tax returns.

W. Scott Simpson, a Justice Department lawyer defending the government, said the Obama administration agrees the federal law is discriminatory and supports its repeal.

But Simpson said the department is obliged to follow the long-standing practice of defending federal laws signed by previous presidents as long as the statutes are constitutional, which, he contends, the Defense of Marriage Act is.

He said Congress had a legitimate rationale to pass the federal law 14 years ago, given that some states were beginning to consider legalizing same-sex marriage. DOMA, he said, maintains the status quo -- marriage reserved exclusively for heterosexuals -- and prevented the federal government from having to keep track of which states had legalized gay marriages and which had not.

'"This presidential administration disagrees with DOMA as a matter of policy," he said, in a courtroom overflowing with gay marriage supporters, including the 17 plaintiffs, who were allowed to sit in the jury box. "But that does not affect its constitutionality."

The lawsuit is widely considered the first serious challenge to DOMA and, regardless of how Tauro rules, is expected to ultimately end up before the Supreme Court. The federal government has asked Tauro to dismiss the complaint, while the plaintiffs have asked the judge to rule in their favor on summary judgment.

Tauro, who interrupted both sides with numerous questions, said he would take the matter under advisement.

The plaintiffs include Dean T. Hara, the husband of the late retired Congressman Gerry E. Studds. Outside the courthouse, Hara said the US was "not a country built on double standards," and he rejected government arguments in favor of "incrementalism."

"I think that's the equivalent of going to Rosa Parks and saying, 'You can move up one row of the bus at a time and eventually you'll get to the front,'" said Hara, a 52-year-old Boston financial adviser.

If the plaintiffs win, it will not extend same-sex marriage beyond the states where it is legal. Nor would it require other states to recognize same-sex marriages carried out in states where it is legal. But it would dismantle a federal statute that affects more than 1,000 marriage-related benefits and would be a huge symbolic victory for supporters of same-sex marriage.