Vice President Joe Biden appeared to fully endorse same-sex marriage on Sunday, telling NBC's David Gregory that while President Obama sets policy, he himself is "absolutely comfortable with the fact that men marrying men, women marrying women, and heterosexual men and women marrying another are entitled to the same exact rights, all the civil rights." (Watch the video below.) That personal stamp of approval trumps Obama's famously "evolving" stance on gay marriage, and Team Obama was quick to say that Biden is basically agreeing with the president, that same-sex couples deserve the same legal rights and protections as opposite-sex couples. Almost nobody is buying that "clarification." What does Biden's gay-matrimony revelation mean for the White House, gay rights, and the 2012 election? Here, five possibilities:

1. Biden accidentally outed Obama

This is why when Joe Biden talks, "people listen," says Jonathan Capehart at The Washington Post: "He's bound to say something to make the president or the administration or both uncomfortable." Endorsing gay marriage is one of those things. Like a lot of liberals, and plenty of conservatives, "I don't believe that Obama really opposes same-sex marriage," says Kevin Drum at Mother Jones, but for whatever reason, he "considers it politically expedient to keep pretending otherwise." And unlike Biden, Obama has "cast iron self-discipline" to stay on-message.

2. Maybe Obama will clearly back gay marriage soon, too

This isn't another case of Biden shooting from the mouth, says Lisa Graas at Catholic Bandita. It's "clearly a trial balloon for the president," and "if America doesn't rise up and pop it, then we can expect Obama to campaign for same-sex 'marriage.'" It wouldn't be the first case of Obama "using a top surrogate to send a message" on gay rights, say Brian Knowlton and Michael Barbaro at The New York Times. And in previous cases, Obama has followed up those messages with a show of support.

3. This could spell trouble for Obama with key voters...

Team Obama's quick "backtrack indicates that it doesn't want this to become a major issue," and that Biden was indeed speaking for himself, says Brett LoGiurato at Business Insider. A recent Pew survey shows "why Obama could be hesitant to support something as momentous as gay marriage": Support is under 50 percent in some "crucial voting blocs," such as black voters. And North Carolina, where Obama's holding his convention this summer, is about to pass a sweeping gay-marriage ban on Tuesday. Oh, "let's be realistic," says Doug Mataconis at Outside the Beltway. "The vast majority of the people who would be pissed off if Obama said he supported same-sex marriage aren't going to vote for him anyway."

4. ...And land Obama in hot water with gay-rights advocates

If Biden was trying to highlight the list of things Obama has done for gays and lesbians, says Edward-Isaac Dovere at Politico, it might have backfired by name-checking "the biggest thing missing from that list." Gay-rights advocates area already frustrated that Obama won't just come out and support same-sex matrimony, and this quick walkback of Biden's strong endorsement is "turning impatience into anger." Some advocates even see the damage from Obama's unwillingness to "evolve" hurting him with more than just gays and lesbians. "Voters like authenticity, and 'evolving' as a position is about as inauthentic as you can get," political strategist Richard Socarides tells Politico.

5. Biden's words won't change anything

It would be nice if Obama was as effusive about gay marriage as Biden was on Sunday, but "what Obama fails to do rhetorically he's more than making up for in action," says The Washington Post's Capehart. More to the point, Team Obama is right: Biden didn't really endorse marriage equality, says Andrew Sullivan at The Daily Beast. But who cares? Gays and lesbians will win the right to marriage by changing hearts and minds, "not by begging presidents to back us."