US Election:In both parties electors rejected the political establishment and chose candidates for their personal style and character rather than policies, writes Denis Stauntonin Des Moines.
For Democrats, it was the triumph of Hope over experience as Iowans embraced Barack Obama's visionary rhetoric of change and dumped Hillary Clinton's promise of steady, tested leadership.
Republicans saw a crumpled David, in the shape of pastor turned politician Mike Huckabee, vanquish the gold-plated Goliath of venture capitalist turned governor Mitt Romney.
In each party, voters rejected the political establishment and chose politicians on the basis of their personal style and character rather than on policies.
Obama's victory and Clinton's third place finish have transformed the Democratic race overnight, stripping the former first lady of any claim to be the "inevitable" candidate and making next Tuesday's primary in New Hampshire a make-or- break poll for her.
Two candidates, Senators Joe Biden and Chris Dodd, have retired from the Democratic race and two others, Bill Richardson and Dennis Kucinich, have no prospect of breaking out of the low single digits.
John Edwards tried to present his second place in Iowa as evidence that voters had rejected Clinton, leaving the contest between himself and Obama. Nobody is buying this analysis, not least because Edwards staked so much on Iowa and failed to improve on his result there in 2004.
The scale and the nature of Obama's victory have propelled him into a formidable position ahead of Tuesday's primary, where independent voters are again expected to play a crucial role. Obama showed in Iowa that he can attract Independents, Republicans and legions of new, young voters into the Democratic fold, reinforcing his claim to be the most electable Democrat in November.
Thursday night's result also proved that the huge, enthusiastic crowds Obama has attracted throughout the country can be translated into concrete, electoral facts.
Clinton's poor showing and her failure to win over more than a fraction of Independents - or even to secure many second preferences from other Democratic candidates - appeared to confirm her lack of appeal beyond a narrow, base.
Reaching beyond the partisan divide has been a key element of Obama's political message ever since he shot to prominence with a speech to the 2004 Democratic national convention. In his victory speech on Thursday night, he said he wanted "to end the political strategy that's about division instead of addition; to build a coalition that stretches between red states and blue states, because that's how we will win in November and that's how we will finally meet the challenges that we face as a nation".
Clinton has been bloodied but she is not yet beaten and her campaign strategists have indicated that, over the next few days, they will use new TV adverts to point up "contrasts" with Obama. This is code for negative adverts, drawing attention to inconsistencies in Obama's record on issues like gun control and health care, on which he used to hold more radical views.
Clinton herself will have an opportunity to target Obama at a debate in New Hampshire this evening and her campaign is confident that it has a better chance of victory in the Granite State than in Iowa.
Although Huckabee's win in Iowa was an extraordinary achievement, it will have a less dramatic immediate impact on the Republican race, partly because that race is so disorderly. There is still no frontrunner and five candidates have a plausible chance of winning the nomination: Huckabee, Romney, McCain, Giuliani and Thompson.
Huckabee has admitted that he has no real hope of winning New Hampshire, which is socially liberal and generally immune to his brand of southern charm. He could win South Carolina, however, and is running level with Giuliani in Florida.
The conventional Washington wisdom is that Huckabee can't win the nomination because he has no money, knows nothing about foreign policy and is too conservative on social issues for most Americans.
He does, however, represent a new kind of Republican - populist on economic issues and as quick to criticise corporate greed as any Democrat but adamantly opposed to abortion and gay rights. He is the most gifted TV performer within the Republican field and the most recognisably human, with the possible exception of McCain.
On Tuesday, however, the contest will be between Romney and McCain and each must win New Hampshire to remain viable for the nomination. Ron Paul, whose libertarian campaign netted $20 million in contributions in the last quarter, should do well in New Hampshire and could even come in third but can expect few successes after that.
Thompson's third place in Iowa has kept him in the race, although he has shown little enthusiasm for the campaign. Giuliani is sitting out the early races, hoping that a win in Florida at the end of this month will launch him into a string of triumphs on February 5th, when more than 20 states vote.