If Vice President Biden continues to appear in public during this campaign, White House press secretary Jay Carney should be offered a membership in the janitors' union. As things stand, the spokesman does not have the supplies to clean up the mess Biden made Sunday on NBC's Meet the Press.

Biden gave his full support to same-sex marriage, a position conspicuously at odds with the public stance of President Obama, who is widely assumed to share Biden's view but says his thinking is "evolving." Biden's classic Washington gaffe was accidentally speaking the truth, making Obama's position — neither for nor against, but in an evolutionary state, not unlike a Galapagos finch — all the more untenable.

On Monday, Carney was left with cleanup duty. But the more he swabbed the mess, the more it spread.

ABC's Jake Tapper said "it seems cynical to hide this until after the election." NBC's Chuck Todd said with a grin, "So help me out here. He opposes bans on gay marriage, but he doesn't yet support gay marriage?"

Carney tried to parry the questions, gamely at first and then testily as reporters began to laugh.

Biden hadn't planned to make news. He had been relatively on message for months. But on Sunday, he referred to the likely GOP nominee as "President Romney" and to his boss as "President Clinton." And he inadvertently made Obama's position on gay marriage look more absurd.

By Monday, even Education Secretary Arne Duncan was asked about such unions. (He supports them.) Housing and Urban Development Secretary Shaun Donovan has already expressed support. Next: Energy Secretary Steven Chu?

There was little doubt in the briefing room that Obama supports gay marriage and will go public after Election Day. Carney had the unenviable task of trying to convince the press otherwise.

"I have no update on the president's personal views," he told the first questioner. "He, as you know, said that his views on this were evolving."

Tapper asked whether Obama was "still evolving" or whether he's "just waiting for the proper time to drop it, likely after November."

"It is as it was," Carney said.

CBS's Norah O'Donnell tried another approach: "Why does the president oppose same-sex marriage?"

"I really don't have an update for you," Carney answered.

"The vice president appears to have evolved on the issue, but the president is still evolving?"

"I will leave it to individuals to describe their own personal views."

Reporters fired dozens of barbs and taunts. "What do you think the word evolving means?" "Is he unevolved?" Carney let out a sigh. Obama's views, he maintained, "are crystal clear."

Chris Geidner of Metro Weekly, a gay publication, asked, "If he's crystal clear, why is everybody in this room asking you questions?"

"I think everybody in this room is reacting in the way that folks often do to one story that takes off, and then they run ... and chase it." And the press secretary runs after them, mop in hand.

Dana Milbank writes for the Washington Post.