Clinton spoke for 30 minutes at the Take Back America conference, where about 3,000 liberals are gathered, and tried to assure them she had reversed her initial support for the war in Iraq and now wanted a deadline to withdraw the troops, The New York Times reported.
The celebrity-sprinkled conference is hosted by Campaign for America's Future, which describes itself as progressive, rather than liberal, a Chicago Tribune correspondent reported.
"This (turnout) reflects the increasing strength of the progressive movement and the sense that we're driving the political debate," Robert Borosage, the campaign's co-director, told the newspaper. "There's a general sense that the conservative era of the last 25 years is over. The public is moving our way, and we are moving politicians our way."
The Rev. Al Sharpton broadcast his radio show from the conference site at the Washington Hilton, while actor Jason Alexander emceed the conference's awards dinner Tuesday night. Filmmaker Michael Moore was also there to preview his movie, "Sicko," which slams the U.S. healthcare system.
2014: The Year in Music [PHOTOS]