Angered conservatives are vowing to make same-sex marriage a front-burner election issue, nationally and in the states, following the Obama administration's announcement that it will no longer defend the federal law denying recognition to gay married couples.
"The ripple effect nationwide will be to galvanize supporters of marriage," said staff counsel Jim Campbell of Alliance Defense Fund, a conservative legal group.
On the federal level, opponents of same-sex marriage urged Republican leaders in the House of Representatives to intervene on their own to defend the 1996 Defense of Marriage Act, or DOMA, against pending court challenges.
"The president has thrown down the gauntlet, challenging Congress," said Tony Perkins of the Family Research Council. "It is incumbent upon the Republican leadership to respond by intervening to defend DOMA, or they will become complicit in the president's neglect of duty."
Conservatives also said they would now expect the eventual 2012 GOP presidential nominee to highlight the marriage debate as part of a challenge to Obama, putting the issue on equal footing with the economy.
Gay rights activists welcomed Wednesday's announcement from the Justice Department, sensing that it would bolster the prospects for same-sex marriage in the courts. Among Democrats in Congress, there was praise for Obama's decision and talk of proposing legislation to repeal the law altogether.
"I opposed the Defense of Marriage Act in 1996. It was the wrong law then; it is the wrong law now," said Sen. Diane Feinstein, D-Calif. "My own belief is that when two people love each other and enter the contract of marriage, the federal government should honor that."
On the state level, there were swift repercussions.
In Rhode Island, the Roman Catholic bishop of Providence, Thomas Tobin, said Thursday that his diocese would "redouble its efforts' to defeat a pending same-sex marriage bill in response to the announcement. In Iowa, conservative activist Bob Vander Plaats said the DOMA decision would invigorate a campaign to repeal the state's court-ordered same-sex marriage law.
"This gives us more credibility than ever with this issue," said Vander Plaats, who wants to topple the Democratic leadership in the state Senate that is blocking efforts to put a same-sex marriage repeal proposal on the ballot.
In Maryland, meanwhile, the state Senate was debating a bill that would make that state the sixth to legalize same-sex marriage _ joining Iowa, Massachusetts, Connecticut, Vermont and New Hampshire.
Linsey Pecikonis of the gay-rights group Equality Maryland predicted the DOMA announcement would improve the bill's prospects.
"It's a recognition that government is no longer able to defend discrimination," she said.
In Congress, GOP House leaders gave no immediate indication whether they would intervene to defend DOMA in the ongoing lawsuits, but they harshly criticized Obama's decision.
"This is the real politicization of the Justice Department _ when the personal views of the president override the government's duty to defend the law of the land," said House Judiciary Chairman Lamar Smith, R-Texas. "It's disappointing that the Obama administration continues to place politics above the will of the American people."
In fact, many polls show the public almost evenly divided on legalizing same-sex marriage, one reason the issue is so volatile politically.
Perkins, the Family Research Council leader, suggested that House Republicans would risk alienating their conservative base if they did not tackle the marriage issue head-on.
"The president was kind of tossing this cultural grenade into the Republican camp," he said.
"If they ignore this, it becomes an issue that will lead to some very troubling outcomes for Republicans."
Jon Davidson, legal director of the gay-rights group Lambda Legal, predicted the DOMA announcement would energize opponents of gay marriage, but he questioned whether that would have much impact on the 2012 presidential race.
"I think they will try to turn this into a major election issue," he said. "But the people who feel strongly that same-sex couples should not be allowed to marry were not going to vote for President Obama anyway."
Conversely, he said the gay community will rally behind Obama all the more eagerly.
"It's hard to imagine that with the repeal of `don't ask, don't tell' (enabling gays to serve openly in the military) and this decision, there will be anything less than enthusiastic support," he said.
Though the DOMA announcement elated gays and infuriated many conservatives, it did not do away with the law, which bars the federal government from recognizing gay marriages and allows states to deny recognition of same-sex unions performed elsewhere. Among its many effects, it forces same-sex married couples to file separate U.S. tax returns, and bars the transfer of Social Security benefits to a surviving same-sex spouse.
In California, where the fate of the state's same-sex marriage ban is in the hands of a federal appeals court, gay rights advocates welcomed the administration's action as validation of their plan to get the U.S. Supreme Court to consider the gay marriage issue. While the California case does not hinge on DOMA, lawyers for two couples suing to overturn Proposition 8 are relying on many of the same constitutional arguments made by the Justice Department.
One of the lawyers, Ted Olson, said the federal government's stance bolsters the positions taken by former Gov. Arnold Schwarzenegger and Gov. Jerry Brown in his previous role as attorney general when they decided not to defend Proposition 8. The net effect, he said, "will be very persuasive" as judges weigh the case.
California is among 30 states which have passed constitutional amendments aimed at prohibiting same-sex marriage.
Brian Brown, president of the conservative National Organization for Marriage, predicted that Obama's decision not to defend the federal DOMA would spur efforts in some of the remaining states to join the ranks of those with constitutional bans.
Indiana lawmakers took a step in that direction last week, and Brown said it was possible that amendments could gain traction in Wyoming, Minnesota, North Carolina and even New Hampshire, if GOP lawmakers succeed in repealing the state's same-sex marriage law.
"This raises the stakes and makes clear the executive branch is not willing to carry out its responsibility," Brown said. "I don't think by any stretch of the imagination the tables have turned on this issue. People in this country know what marriage is."
When DOMA was passed in 1996, an election year, it had broad bipartisan support. Over recent years, Obama has criticized the federal law without fully supporting gay marriage. White House spokesman Jay Carney said this week that the president was "grappling" with the issue but had always personally opposed DOMA as "unnecessary and unfair."
The Williams Institute, a think tank at the UCLA School of Law, estimates that about 80,000 legally married same-sex couples live in the U.S., including roughly 30,000 who wed in Canada or other foreign countries. An estimated 85,000 same-sex couples have entered civil unions or domestic partnerships, the institute says.
David Crary reported from New York and Lisa Leff from San Francisco.