By Jeff Mason and Samuel P. Jacobs
WASHINGTON (Reuters) - Was it a signal by President Barack Obama's re-election campaign, designed to attract gay and lesbian supporters? A trial balloon to test voters' feelings about same-sex marriage? Or just a case of the vice president wandering from the campaign's message?
Whatever it was, Vice President Joe Biden's endorsement on Sunday of the right of gay couples to marry revved up the activist community - and created a bit of a headache for Obama's re-election campaign, which wanted to spend Monday talking about the economy and other issues.
Biden declared on NBC's "Meet the Press" program that he was "absolutely comfortable" allowing same-gender couples to wed.
That, and a subsequent comment on MSNBC's "Morning Joe" from Education Secretary Arne Duncan that gay marriage should be legal, led White House and campaign officials to spend the day fending off questions about the president's views.
Obama, who enjoyed broad support from the gay and lesbian community in the 2008 election, opposes same-sex marriage but has said gay couples should have the same rights as married straight couples. He has characterized his stance as evolving.
David Axelrod, the president's senior campaign strategist, told reporters Biden's comments were "entirely consistent with the president's position, which is that couples who are married, whether they're gay or heterosexual couples, are entitled to the very same rights and the very same liberties."
Some gay rights activists saw Biden's remarks as more significant.
Biden's candid response, they said, could be seen as a sign that Obama had arrived at the same conclusion on the divisive issue - even if he is waiting until after the November 6 election to make that clear.
"Any reasonable person watching that broadcast of 'Meet the Press' yesterday walked away with the impression that Vice President Biden supported marriage equality," said Fred Zaines of the Human Rights Campaign, a group that lobbies for lesbian, gay, bisexual and transgender people's rights.
"If, as Axelrod says, the vice president's position is equal to that of the president, well then the president just came out for marriage equality."
White House spokesman Jay Carney said there was no change in the president's position.
"I have no update on the president's personal views," he said. "What the vice president said yesterday was to make the same point that the president has made previously: that committed and loving same-sex couples deserve the same rights and protections enjoyed by all Americans, and that we oppose any effort to roll back those rights."
Since becoming president in January 2009, Obama has signed a repeal of the policy that prevented gays from openly serving in the military. The White House also has declined to defend the constitutionality of the 1996 Defense of Marriage Act, a federal law that defines marriage as a union between a man and a woman.
'YOU CAN'T GO BACK NOW'
An increasing number of Americans now favor gay marriage.
In a survey released last month, the Pew Research Center found 47 percent of people favored same-sex marriage while 43 percent opposed legal marriages by gay and lesbian couples. In 2008, 39 percent favored gay marriage and 51 percent opposed it.
Biden belongs to the Catholic Church, which opposes gay marriage. However, his views seem to be in line with most Catholics in the United States: Pew recently found that 52 percent of church members favor gay marriage, up from 46 percent in 2010.
Gay rights activists said Biden's comments could help Obama with the gay community if his advisers did not overshadow them.
"I don't know whether it's a trial balloon. I don't know whether it was just the vice president speaking freely about how he feels. But you can't go back now and try to undo what he said," said Winnie Stachelberg, executive vice president of the liberal Center for American Progress and a former official at the Human Rights Campaign.
"The notion that he actually didn't come out for marriage equality is somewhat ludicrous," she said.
Biden has a well-established reputation for wandering off script.
In 2010 he greeted the signing of Obama's healthcare overhaul with a widely reported expletive. And in 2007, as a senator, he had to apologize for calling Obama "the first mainstream African-American (presidential candidate) who is articulate and bright and clean and a nice-looking guy."
As the 2012 campaign has heated up, the vice president has played the role of attack dog, leading the assault on Republican challenger Mitt Romney with a series of addresses in politically divided states that likely will decide the November 6 election.
An Obama endorsement of gay marriage could help energize core Democratic supporters but it could alienate some independent voters with conservative social views.
"Voters will respect you if you tell them the truth, even if they disagree with you," said Richard Socarides, a gay rights advocate and former adviser to President Bill Clinton.
"It's clear to everyone that (Obama's advisers) have made a political calculation to try to avoid this issue, but I think ultimately it will backfire on them because this is too big an issue and it's at the center of a national conversation we're having. The president can't be silent."
Obama's campaign has not been silent about Romney's record on gay rights.
After an openly gay foreign policy spokesman resigned from the Romney campaign last week, Obama's spokesman accused the former Massachusetts governor of not being able to stand up to conservative Republicans who had complained about the policy aide's appointment.
Marriage equality advocates note that a few prominent Republicans - including former Vice President Dick Cheney, whose daughter, Mary, is openly lesbian - have emerged as leaders in the fight for gay marriage.
In 2011, it was primarily wealthy conservatives such as Paul Singer, a money manager who has given $1 million to a pro-Romney "Super PAC," who provided the resources for the campaign in New York that made same-sex marriages legal in the state last year.
Six states, plus the District of Columbia, have extended marriage rights to gay couples. Twenty-eight states ban such marriages.
On Tuesday, voters in North Carolina, the state where Democrats will hold their national convention in early September, are widely expected to approve a measure that would ban gay marriage there.
(Additional reporting by Laura MacInnis and Lily Kuo; Editing by David Lindsey and Christopher Wilson)