The efforts of gay bloggers and activists to derail a gay DNC fundraiser in protest of Obama's hesitation to take on gay rights has racked up impressive defections but the event's gay co-chairs say they'll still attend.

Tonight's LGBT Leadership Council Dinner is a $1,000-a-plate minimum fundraiser featuring Vice President Joseph R. Biden. The fundraiser has become the target of gay activists who are pressuring gay donors to stop giving to the Democratic Party.

The gay activists argue that so long as the “gay ATM” is filling Democratic Party coffers, the party is likely to continue offering lip service over action on gay rights.

“The Democrats don't seem to care much about our civil rights, but when the gay ATM goes bust, suddenly we get our calls returned,” wrote Joe Sudbay at AmericaBlog, one of the blogs supporting the boycott.

Donors began to flee after boycott organizers announced they would picket outside the Mandarin Oriental Hotel tonight, and gay weekly the Washington Blade said it will video tape anyone who crosses their picket line.

By Wednesday the body count was adding up. Eleven donors had signaled they were not attending, including Vermont Senate Pro Tempore Peter Shumlin, who shepherded the first gay marriage bill through the Vermont Legislature, openly gay philanthropist Bruce Bastian, and gay activist David Mixner.

But the biggest win so far is former DNC Chairman Howard Dean, an event co-chair. Dean released a statement Wednesday that he would not attend due to a “family commitment.” The former presidential candidate said he was committed to the event and would send a video message to attendees.

Gay activists already dissatisfied with President Obama on gay rights hit their breaking point two weeks ago with the news that the Department of Justice filed a brief in support of the Defense of Marriage Act, or DOMA, the 1996 law that defines marriage as a heterosexual union for federal agencies and allows states to ignore legal gay marriages performed elsewhere.

The brief drew fire from activists who say it draws parallels between gay marriage and incestuous and polygamous relationships, and it relied heavily on outdated and inaccurate gay stereotypes.

“The brief was very troubling to a lot of people and rightfully so,” Richard Socarides, a former special assistant to President Clinton who is also boycotting the fundraiser, told ABC News. “Supporters of the Democratic Party and others who feel that gay and lesbian equality is an important issue to address are rightly concerned about this brief. Serious issues still need to be clarified.”

So far, however, the administration has remained mum on the brief, saying only that the president has a duty to defend the law.

“[T]he Justice Department is charged with upholding the law of the land, even though the president believes the law should be repealed,” White House Spokesman Robert Gibbs said.

But while activists have managed to shake some fruit off the vine, event co-chairs Representatives Barney Frank of Massachusetts, Jared Polis of Colorado, and Tammy Baldwin of Wisconsin – the gay community's de facto representation in Congress – say they remain committed to the event.

“There are a lot of people who aren't boycotting [the DNC fundraiser],” Frank said. “I think it's a mistake to deny money to the DNC.”

Polis also defended his decision, telling gay weekly Bay Area Reporter: “I am a Democrat and a proud Democrat. Our party is not perfect but we need to make it better. There is an enormous difference between the Republican and Democratic Party on equality issues.”