Kerry, lagging behind Dean and Gephardt in Iowa until last week, beat them among virtually every major group of voters. Kerry displayed remarkably consistent appeal to men and women, working-class and more affluent voters, liberals and moderates, and those with and without college educations, the survey of caucus-goers found.
Although the Iowa impact on the New Hampshire primary has been uneven over the years, Monday's results could unsettle that contest. In recent polling, Dean's once-formidable lead in New Hampshire has eroded, with retired Army Gen. Wesley K. Clark, who chose not to compete in Iowa, a close second. Kerry, meanwhile, has surged to a virtual dead heat with Clark.
Both Kerry and Edwards are likely to receive a boost from the Iowa results, increasing the pressure on Dean and Clark and creating the potential for a tight four-way race in next Tuesday's New Hampshire vote.
Monday's poll of Iowa caucus-goers found that Kerry and Edwards surged among voters who made their decisions in the week before the caucuses. Dean and Gephardt attacked each other with negative television ads in Iowa at the start of that period. Both of their campaigns concluded that the crossfire ended up hurting them and helping Kerry and Edwards.
Dean's third-place finish represented a severe setback for a candidate who had led in the polls here and nationally through most of the fall.
Perhaps the most ominous aspect for Dean was that caucus-goers overwhelmingly agreed with his position on the Iraq war -- the survey found that 75 percent of them opposed it.
But the primacy of that issue apparently has receded among Iowa voters. According to the poll, Dean ran ahead among those who said the war was the most important issue in their decision. But they represented just one-seventh of those who participated. Far more voters cited the economy and health care as their main concerns.
For Dean, these findings suggest his first imperative as the race moves to New Hampshire could be to broaden his message and appeal.
Gephardt's showing apparently spelled the end of his presidential hopes. He not only placed fourth in a state that he carried in his 1988 presidential bid but failed to hold the groups that had been his base in Iowa: seniors, voters without a college education and union members. Kerry carried all three of those groups, and Edwards beat Gephardt with the first two and tied him with the third, the poll found.
The National Election Pool Survey contacted 1,659 voters across Iowa as they entered 50 precincts Monday night. The survey used a confidential, self-administered questionnaire. The margin of sampling error was plus or minus 3 percentage points. For some subgroups, the margin could be somewhat higher.
The survey was conducted by Edison Media Research and Mitofsky International, a cooperative arrangement among ABC News, Associated Press, CBS News, CNN, Fox News and NBC News.
The official results from the Iowa Democratic Party measured the allocation of delegates from the caucuses. Because of the rules governing the allocation of delegates -- for instance, candidates receive no delegates in precincts where they attract less than 15 percent of the vote -- the preferences measured in the entrance poll and the delegate allocation totals vary somewhat.
But both results pointed to the same story: a dramatic surge for Kerry and Edwards, a dramatic decline for Dean and a virtual collapse for Gephardt.
For Kerry and Edwards, the breadth of support they attracted could be a powerful asset as the race advances into states that represent different elements of the Democratic Party.
In New Hampshire on Tuesday, the candidates will confront an electorate dominated by well-educated, liberal voters. In several of the key states that follow on Feb. 3 -- such as South Carolina and Oklahoma -- blue-collar voters are likely to cast a majority of the votes. With Gephardt's expected withdrawal today, Missouri also looms as a major test on Feb. 3.
Clearly in Iowa, the momentum in the final days belonged to Kerry and Edwards, creating a wave that overwhelmed the extensive ground organizations that Gephardt and Dean built.
Among those who made their decisions within the last week, Kerry won 39 percent and Edwards 35 percent, while Dean attracted just 14 percent, and Gephardt only 6 percent. By contrast, among those who decided earlier, 33 percent were for Kerry, 26 percent for Dean, 19 percent for Edwards and 15 percent for Gephardt.
Joe Trippi, Dean's campaign manager, attributed the late shift toward Kerry and Edwards on the intense acrimony between Dean and Gephardt that culminated in dueling television ads.
"What happened here is that we got in a dogfight with Dick Gephardt," Trippi said. "Dick Gephardt was in a fight for his life in Iowa. We got out there and got in his way, by getting into a lead, and they just hammered the living daylights out of us while John Kerry and John Edwards just floated up, the only guys with positive messages."
In polling throughout the fall, Dean had been strongest among college graduates and liberals. But in Monday's poll, he finished well behind Kerry and no better than even with Edwards with both groups. Even voters who considered themselves strongly partisan Democrats preferred Kerry and Edwards to Dean.
Meanwhile, both Kerry and Edwards ran much better than Dean among moderates and voters without a college education.
Kerry beat Gephardt among union members, which have been the core of Gephardt's campaign. While Gephardt narrowly won union members without a college degree -- largely those within the industrial unions that launched a major independent effort on his behalf -- he finished a distant fourth among union households with college degrees. Overall, only 1 in 14 caucus participants who attended college voted for Gephardt.
Kerry's strengths among Iowa voters were his experience and his potential as a general election candidate against Bush, the poll found. Among the 15 percent of those attending who said experience was the most important factor in their vote, Kerry was backed by 71 percent. Among the one- quarter of voters who said the ability to beat Bush was their top concern, Kerry won a 37 percent plurality.
For Edwards, electability was also a key asset. He won 30 percent of those who said that was their priority. Edwards dominated among the slightly more than one-fifth of voters who said their priority was a candidate who cares about people like them.
Although Dean and Gephardt made health care central to their campaigns, Kerry won comfortably among voters who named that issue as most important to them.
Edwards ran about even with Kerry among those who cited the economy.