The Democratic candidate Howard Dean is fighting hard to retain the narrow lead he holds in next week's crucial and increasingly bitter-fought Iowa caucuses - launching a series of attacks on his opponents and reiterating his claim to be the only genuine alternative to President George Bush.
Latest polls suggest that with less than week to go, the former Vermont governor is leading Dick Gephardt, the former Democratic leader in the House, by a slim three-point margin. Despite a recent surge from both John Kerry and John Edwards, they remain in third and fourth place respectively and are not expected to shift from those positions.
With campaigning becoming ever more intense and the attacks on Mr Dean growing increasingly barbed, there are clear indications that the former doctor is feeling the heat, and in recent days he has been rather more outspoken in his criticisms of his opponents. "I'm going after everybody because I'm tired of being the pincushion here," Mr Dean said at a campaign event in Iowa on Monday evening.
He went on to tell several audiences of voters that if they wanted real change in the nation's capital they should not vote for a Washington politician. Singling out Mr Kerry, Mr Edwards and Mr Gephardt by name for their support for the decision to invade Iraq, he added: "I want you to remember a week from tonight when you caucus who stood up against that war when no one else would."
In recent weeks, Mr Dean's status as Democratic front-runner has led him and his policies to be placed under unprecedented scrutiny by political pundits and the US media. This has led to a number of claims that he has shifted his position on key issues and, potentially much more damaging, accusations that he has made a series of "gaffes". These have been seized on by his opponents and former general Wesley Clark, who is not taking part in the Iowa contest, has moved into a close second in the polls for the New Hampshire primary on 27 January.
There is more than a suggestion, however, that the flurry of stories pointing to a "shakiness" in Mr Dean's campaign and claims that support for him is decreasing, are based less on real evidence rather than a concerted effort by some Democrats and by Republicans to do everything and anything to stop him becoming the party's candidate.
The political writer Eric Boehlert suggested yesterday on the Salon.com website that, fed with slurs from his opponents, the Washington press corp had unfairly focused on Mr Dean's alleged "bad temper" and "gaffes". He wrote: "A look at the last half-year of media coverage ... raises the question: has his anger been so uncontrollable, his campaign miscues so frequent, are his political chances so unlikely, as to merit the unrelenting focus on anger, gaffes and so-called unelectability that has come to dominate reporting on Dean?"
Faced with this, it seems that Mr Dean has made a conscious decision to sharpen his attacks on his rivals and to try and alter the perception that he has spent much of the last few weeks on the defensive. Just a week ago he told reporters he would remain above the fray, saying: "I think the way to deal with [attacks from opponents] is not to go back at them because I think that's what voters don't like."
That is no longer the case. Again on Monday - Mr Dean was not campaigning yesterday - he returned to his popular claim of being a Washington outsider, telling voters: "We don't just need change in presidents. We need change in Washington and we're not going to get it by electing someone from Washington."
Mr Gephardt, Mr Dean's closest challenger in Iowa, could not be more of a Washington politician. The Missouri Congressman has spent more than two decades in national politics and previously ran for the US presidency in 1988 when he won the contest in Iowa.
Observers believe the Iowa vote is a make-or-break event for Mr Gephardt. He has claimed that his experiences in 1988 taught him that he cannot afford a one-state strategy if he hopes to become Mr Bush's challenger. But most observers agree that if he fails to win, or at the very least come an extremely close second, his chances of winning the overall Democratic nomination are all but over.
At the same time, if Mr Dean failed to win in Iowa it would change the dynamics of the race and would most likely boost the fortunes of Mr Clark.
Yesterday Mr Gephardt attacked Mr Bush on national security, claiming in a speech to the Council on Foreign Relations that America had several warnings of a likely attack before 11 September, 2001, but failed to act.
"You've got to deal with the symptoms," he said. "The greatest failing of this administration is that they are doing little to deal with the root causes of this problem. This is a serious, long-term, multi-layered problem."Reuse content