New polls Sunday showed Democrats waging a desperate single-digit struggle four days before Iowa's leadoff US presidential nominating contest, and Republican Mitt Romney on the rebound.
Iowa residents wait for Democratic presidential candidate Sen. John Edwards to speak at a campaign event at the Giggling Goat banquet hall in Boone, Iowa. New polls Sunday showed Democrats waging a desperate single-digit struggle four days before Iowa's leadoff US presidential nominating contest, and Republican Mitt Romney bouncing back.(AFP/Getty Images/Win McNamee) (AFP/Louai Beshara) (AFP/Saeed Khan)
Former Democratic vice-presidential nominee John Edwards put on a spurt in one new survey, and Hillary Clinton led another, with Barack Obama closing out a nervy dead heat heading into Iowa's critical caucuses on Thursday.
Republican Mike Huckabee meanwhile accused Romney of running a dishonest campaign, as he staggered under a withering barrage of negative attack ads from his rival, which appear to have halted his surge in state polls.
The caucuses are a crucial first test for candidates, and have the potential to send victors onto later contests with a jolt of momentum, and could effectively snuff out the challenge of candidates who disappoint.
Clinton, despite consistently topping national surveys, has failed to break her rivals in Iowa, and said Sunday even third place on Thursday would not spell disaster heading into the New Hampshire primary on January 8.
"I believe that this campaign will be bunched up, I think the history out of Iowa shows that a lot of people live to fight another day," Clinton told ABC News.
Obama, the charismatic senator vying to become America's first black president, paints Clinton as a symbol of fractured Washington politics, and denied polls showed he had hit a roadblock.
"We are seeing unbelievable crowds that are two, three times what we are seeing in other campaigns," he told NBC.
"This is going to be a tight race, the polls are going to be bouncing up and down."
Edwards meanwhile assailed Clinton as a tool of corporate interests, and debunked her claim to be an agent of political change as she strives to make history as America's first woman leader.
"I absolutely believe, to my soul, that this corporate greed and corporate power has an iron-clad hold on our democracy," he told CBS.
"Senator Clinton defends the system in Washington ... I don't think you can defend a broken system and bring about the change that you need."
Edwards surged in an MSNBC/McClatchy poll in Iowa to lead by 24 percent, ahead of Clinton on 23 percent and Obama on 22 percent.
A Zogby survey in notoriously hard-to-poll Iowa, however, had Clinton on 31 percent -- four points ahead of Obama. Edwards was back on 24 percent.
Two surveys of the splintered Republican field suggested Huckabee's stunning surge in Iowa, dubbed the "Hucka-boom," might be turning into a "Hucka-bust."
The MSNBC survey had Romney on 27 to 23 percent for Huckabee, with former senator Fred Thompson on 14 percent. Zogby had former Arkansas governor Huckabee still on top, but by one percent over Romney on 28 percent.
Former Arkansas governor Huckabee lashed out at Romney, accusing him of trying to mislead voters with a volley of ads targeting his record on tax and illegal immigration and his views on foreign policy.
"Mitt Romney is running a very desperate and, frankly, a dishonest campaign," Huckabee said on NBC.
"He's attacked me, and, yesterday -- or Friday, I guess it was, he launched then just a broadside attack against Senator McCain," he complained about the well-heeled former Massachusetts governor.
McCain, the Vietnam war hero and Arizona senator, has been pressuring Romney in New Hampshire, a second key state, which holds its nominating primary on January 8, after resucitating a campaign written off only months before.
Candidates blitzed Sunday morning talk shows and attended church services before heading out for another exhausting day on the campaign trail.
Clinton went on the offensive over Obama's perceived lack of experience, hours after her husband, former president Bill Clinton issued a stark warning of national security dangers looming for the next US leader.
"I think my experience is unique, having been eight years in the White House, having, yes, been part of making history," the former first lady said on ABC.
Last week, Obama said his history of living abroad as a child, and ethnically mixed background, gave him more insight into foreign affairs than simply having "tea" with diplomats abroad, a clear swipe at Clinton.