President Obama is used to hearing his name yelled angrily at conservative Tea Party protests. On Monday night, however, he faced hecklers at a more unlikely venue: a Democratic fundraiser in Los Angeles for California Sen. Barbara Boxer.

And yes, the hecklers were attacking the president from the left. "Repeal 'don't ask, don't tell'!" the protesters yelled, referring to the 1993 military policy that bans gays and lesbians from openly serving. Obama responded, "We are going to do that; hey, hold on a second, hold on a second."

The rest of the crowd then began chanting Obama's signature campaign chant: "Yes we can! Yes we can! Yes we can!" You can watch the outburst — and Obama's replies — here:

During the 2008 campaign, Obama repeatedly pledged to kill the controversial policy, and in January's State of the Union address, he reiterated that vow. But progress has been slow. The administration claims that's because a full repeal would require a separate bill in Congress repudiating the congressionally approved 1993 law — and it's been hard to work such a bill into an already overcrowded Capitol Hill agenda. In March, the Pentagon announced it was relaxing enforcement of the ban, to clear the path for eventual repeal.

Obama returned to the issue of repeal in his Monday speech. "When you've got an ally like Barbara Boxer and you've got an ally like me who are standing for the same thing, then you don't know exactly why you've got to holler, because we already hear you, all right," Obama remarked to applause. "I mean, it would have made more sense to holler that at the people who oppose it."

But the hollering didn't let up. "It's time for equality for all Americans," shouted one. Obama again stressed his opposition to the ban, and again said, "I don't know why you're hollering." The group broke into another "Yes we can!" chant.

Obama then sought to return to the event's main theme: Boxer's re-election. Sen. Boxer "didn't even vote for 'don't ask, don't tell' in the first place," the president noted. "So you know she's going to be in favor of repealing 'don't ask, don't tell.' "

— Brett Michael Dykes is a national affairs writer for Yahoo! News.

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