Rivals for the Democratic presidential nomination are exhibiting deep differences on the war with Iraq, as some in the party worry about political fallout from an anti-war position.

"No Democrat will be elected if they do not convince the American people they will keep them safe," warned Connecticut Sen. Joe Lieberman.

Lieberman was joined by former Vermont Gov. Howard Dean and activist Rev. Al Sharpton at a fund-raising dinner Thursday for more than 500 hard-core party activists.

Sharpton and Dean got loud cheers for their anti-war stance, while Lieberman got a polite response and the occasional shout of "no war" from the back of the room.

A war against Iraq is far less popular among Democratic activists who will settle important early contests in states like Iowa and New Hampshire than among voters as a whole. The Democratic field has been focused on the issue, and arguments against war have gotten a more enthusiastic response.

Jeff Woodburn, a former New Hampshire Democratic chairman and a Lieberman backer, said "it's been difficult to get the activists" to support Lieberman because of the issue, though he predicted it was just a phase.

Dan Harkinson, a backer of North Carolina Sen. John Edwards, said: "I think the war is going to happen and I think the primary is going to happen. There are so many candidates and so much to talk about that it's all going to come into play."

Caroline French, another New Hampshire activist, said that if the debate moves the party to the left, so be it.

"The party has been nudged too far to the right," she said. "The right hasn't worked, so the left is where we need to be."

Dean has been taking that approach. "Our party has supported this president too much," he said. "I want to bring this party back to its roots."

Dean got an ovation Thursday by blasting Bush's threat to disarm Iraq by force, calling it "a unilateral action against a country that doesn't present an immediate threat."

Sharpton said Bush was putting the nation's young at risk while giving tax breaks to wealthy friends. "We must have equal sacrifice and equal patriotism," he said.

Lieberman defended his hawkish stance on war with Iraq. "No Democrat will be elected if they have not convinced the American people they will keep them safe," he said.

Two of the candidates referred to the disputed 2000 presidential election, a topic which still fires up activists.

Bush "is the personification of a set-aside program," said Sharpton. "In 2000, the Supreme Court set aside a whole election to make him president."

Lieberman, the party's vice presidential candidate in 2000, said: "I know how to beat George Bush. Al Gore and I did in 2000."

Edwards and former Illinois Sen. Carol Moseley-Braun were also invited to the dinner Thursday, but they declined, citing schedule conflicts.

Most polls have shown Sen. John Kerry from neighboring Massachusetts with an early lead in New Hampshire, which holds its Democratic primary Jan. 27. Other candidates in the race are Missouri Rep. Dick Gephardt, Ohio Rep. Dennis Kucinich and Florida Sen. Bob Graham, who filed papers Thursday to begin raising money for a full-fledged campaign.