By Jerry Markon, Ed O'Keefe and Sandhya Somashekhar
Washington Post Staff Writers
Wednesday, February 23, 2011; 3:16 PM

The Obama administration announced Wednesday that it will no longer defend the constitutionality of the federal government's ban on recognizing same-sex marriages, a rare legal reversal and the latest in a series of political victories for gay rights activists.

The Justice Department had appealed the decision of a federal judge in Massachusetts who struck down the Defense of Marriage Act in July, saying it was obligated to defend federal statutes. The 1996 law defines marriage from the federal perspective as between a man and a woman, which means same-sex married couples are denied access to marriage-based federal benefits.

In an extraordinary change, Attorney General Eric H. Holder Jr. said Wednesday that he and President Obama had determined - after an extensive review - that the law's key section is unconstitutional. "Given that conclusion, the President has instructed the Department not to defend the statute" in court, Holder said in a statement.

Administration officials said the review was triggered by a court-imposed filing deadline in two new legal challenges to the Defense of Marriage Act, filed in federal courts in New York and Connecticut.

The change in position came after intense lobbying of Justice Department and White House officials by gay rights groups and the American Civil Liberties Union, according to activists familiar with the White House's thinking.The conversations included meetings with White House counsel Robert Bauer and one of Obama's closest advisors, Valerie Jarrett. "There has been an all-out effort to get them to do the right thing," said one activist, who spoke on condition of anonymity to describe internal deliberations.

Obama's relationship with the gay community, a key part of his political base, has been complicated, and activists had strongly opposed the administration's earlier defense of the federal same-sex marriage law. The president has said in the past that he does not support the right of gay couples to marry, though he said in December that his views are "evolving."

White House press secretary Jay Carney said Wednesday that Obama's "position on the Defense of Marriage Act has been consistent: He has long opposed it as unnecessary and unfair." He said that the decision to change the government's legal position is "separate" from Obama's personal views and that the president has been "grappling" with the broader issue of same-sex marriage.

The administration's decision on the federal law comes as gay rights advocates have won a series of recent changes in how the federal government treats gay men and lesbians, including Obama's signing in December of legislation to end the military's "don't ask, don't tell" policy banning gays from openly serving in uniform.

Liberal groups hailed the reversal. "The President has chosen to defend the Constitution of the United States over a discriminatory and clearly unconstitutional law," said Michael Keegan, president of People for the American Way. "That decision should be commended. A discriminatory law like DOMA has no place in a country grounded in the values of freedom and equality."

Richard Socarides, a longtime gay rights activists and director of Equality Matters, said Wednesday's announcement was as significant as Obama's push to end the ban on gays serving openly in the military.

"This is the position he took on the campaign trail, but now the government's policy will match up with the political rhetoric," he said.

Conservative groups vehemently objected, saying the administration's earlier position of defending the law in court was the right one. Holder acknowledged in his statement that the legal reversal was "rare." The Justice Department customarily defends federal laws in court.

"It's a dereliction of duty," said Tom McClusky, senior vice president of Family Research Council Action. "Whether they agree with the law or not is irrelevant. . . . The Obama administration has purposely dropped the ball here."

Same-sex marriage is legal in five states, including Massachusetts, and the District. The Maryland Senate on Wednesday advanced a bill to legalize it, and is expected to give the measure final approval Thursday. But same-sex couples are disqualified from receiving marriage-based federal benefits under the Defense of Marriage Act. Those who oppose the federal law say it requires states to discriminate against their citizens.

One of several reasons why the decision to end the government's defense of the marriage law came this week is that the March 11 filing deadline is two days after the one-year anniversary of the District's same-sex marriage law. The White House was aware that gay rights groups would have used the anniversary to contrast the administration's defense of the law against the District's embrace of marriage equality, according to activists.

Groups opposed to same-sex marriage say they will lobby House Speaker John Boehner (R-Ohio) to hire counsel to defend the law. His office has not said what he will do, but his spokesman Michael Steel criticized the Obama administration for its stand.

"While Americans want Washington to focus on creating jobs and cutting spending, the President will have to explain why he thinks now is the appropriate time to stir up a controversial issue that sharply divides the nation," he said.

A poll by the Pew Research Center for the People and the Press in September found 43 percent of those surveyed favored allowing gays and lesbians to marry legally and 47 percent opposed. This is a high point for favorability of same-sex marriage in the center's polling back to 1996. The poll showed wide partisan divisions: 55 percent of Democrats and 46 percent of independents favored same-sex marriage, but only 21 percent of Republicans. The Washington Post's polls show a similar division and trend.

markonj@washpost.com Post polling manager Peyton M. Craighill also contributed to this story.