Gephardt mostly recounted the central policy proposals of his campaign, such as expanding access to health care and establishing an international minimum wage.
But he also introduced new rhetoric criticizing Bush, portraying him as "the vanishing president" who has "lost" jobs, the budget surplus he inherited from Bill Clinton and support from allies abroad.
He added: "We have lost Osama bin Laden and Saddam Hussein. They've vanished. There's only one answer to this problem: We've got to make George Bush vanish."
Kucinich, a longshot contender, centered his speech on a call for replacing all U.S. troops in Iraq with United Nations forces. "America cannot go it alone; America must stand on truth," he said. "The truth is this administration lied to the American people."
Moseley Braun, the final speaker, married the twin themes of Bush-bashing and Democratic unity before sending the crowd out into a 40-degree night.
"We're going to clean house and we're going to set the country back on a track to peace and prosperity and progress again," she said. "The truth is that all of us will come together and support whoever is our nominee."
Before the dinner, some campaign strategists had privately grumbled that Clinton might overshadow the 2004 contenders, even though she's repeatedly said she does not intend to enter the race. But she delivered a relatively low-key speech that warned the party against excessive "nostalgia" for the 1990s, urged Democrats to unify behind the eventual nominee and joined the candidates in denouncing Bush.
"In just a few short years, this president has squandered two precious surpluses," Clinton charged. "A budget surplus that was obtained because of the hard work of a Democratic president and a Democratic Congress.... He also squandered a surplus of goodwill that this nation had. We had the respect of the world. After 9/11, we were a unified country."
Before the dinner, the candidates had fanned out across the city, participating in a flurry of events.
Gephardt held a downtown rally with union supporters and marched his backers across the street to the dinner.
On Saturday morning, Kerry laced up skates for an hour of ice hockey with Des Moines firefighters, and then addressed a rally of his own.
Edwards began his day with supporters at a tailgate party two hours away at a University of Iowa football game.
Dean drew more than 700 people to a rally at a Des Moines high school that still buzzed with enthusiasm even after the campaign announced that rock singer Melissa Etheridge, who was due to endorse him, had missed her plane.
Dean, a physician, also stopped on his way to the rally to help give medical attention to a campaign organizer, Jake Edwards, who had collapsed with an epileptic seizure. Campaign aides later said Edwards was in good condition at a local hospital.
