America's future in the hands of Iowa's undecided

The wind had cut to the bone and the hoarse voices of candidates had showed the strain of a mid-winter campaign as they made a final appeal for wavering voters at phone banks and impromptu rallies last night.

A huge turnout for Barack Obama at Emmanuel School in Des Moines augured well for his campaign, after he won overwhelming support. A caucus offical said that the turnout was "absolutely beyond belief".

After today's result the field is winnowed down to three or perhaps four candidates for each party. They were busy managing expectations in the event of defeat yesterday. Fifteen years ago, Bill Clinton famously turned a second place showing in New Hampshire to his advantage by calling himself the "Comeback Kid" and went on to win the White House.

But this time it was the undecided who held the whip hand over the candidates. Many voters said they were not even sure if they would go Republican or Democrat in the hours before the caucusing started.

Florence Cline was typical of them. She works in a natural-food store and thought she was a Democrat until she went to see the electric guitar-playing born-again Christian candidate Mike Huckabee. "It's very unusual that I'm here," she said. "I'm intrigued that he's in a rock band, plays bass. He's just a fascinating human being."

The final hours also revealed deep divisions inside the Democratic Party about the best way to win the presidency, even if the candidate's policies are virtually identical. As John Edwards' tour bus wheeled into the parking lot of an old-time ballroom, hulking members of the local steelworkers union escorted him inside where the singer John Mellencamp took the stage.

The Edwards message, that there are two Americas, one privileged and lightly taxed, the other hardworking and teetering on the edge of bankruptcy, suddenly caught the imagination of voters.

On the other side of town Hillary, Bill and Chelsea Clinton were making their way in a convoy of 4WDs to the small but comfortable surroundings of Iowa's historic centre complete with ancient biplanes suspended overhead and a stage coach called a "jerky". Looking preternaturally young and attractive, ("it's the botox," people muttered) she asked her well-groomed audience, "Who is ready to be President?"

It was a message of experience and competence delivered with perfect pitch, that she repeated again on state-wide television hoping to catch Iowans before they bundled up to go out in sub-zero temperatures and caucus.

Then in the cavernous surrounds of a state high school's basketball arena, it was the turn of Barack Obama, the outlier in the race to deliver his message to an audience dominated by people in their early twenties, evenly divided among men and women and, above all, multi-racial. "Who can take us in a fundamentally new direction?" he asked his army of supporters who have taken to the arcane world of political action with a level of enthusiasm they usually reserve for sports and music.

There was less enthusiasm on the Republican side, apart for the evangelical support for Mike Huckabee, and a distinct sense that the candidates have not yet figured out how to motivate the conservative base.

It was also the costliest campaign that Iowa had ever seen, one which attracted tens of thousands of volunteers and paid campaign activists to knock on doors and urge people to caucus. They gathered shortly before 7 pm last night in fire stations, school halls, church basements and town halls to justify their choice of candidate one of the rare occasions in US politics where voters directly interact with each other.