All politics depends on the ability to get out the vote. On Thursday Iowa will be holding the first caucuses in the 2008 US presidential election. The results of these caucuses could give the leading candidates the momentum, sometimes called “the big mo”, that could take them through to the nomination and even to victory in November. Because Iowa comes first, with the New Hampshire primaries second, Iowa has the opportunity to define the early leaders.

There is no state whose collective decision I would trust more. Iowa is largely a farming state, with few large cities and a first-class university, Iowa State. Iowans have the core values of the American Middle West, practical, serious, good-natured, religious and thrifty.

This year Iowa is particularly important. The 2008 primary campaign is starting early. The primaries in most of the bigger states, including California, New York and Illinois, have largely been bunched on Tuesday, February 5, “Super Tuesday”. The expectation is that Super Tuesday will be decisive, and that the two leading candidates in only five weeks' time will be virtually sure of their party's nominations. Iowa is one of the best opportunities that candidates will have to influence the Super Tuesday outcome.

At present the polls in Iowa show a clear leader in the Republican race, but no clear lead among the Democrats. Unfortunately, the leading Republican candidate in Iowa lacks the money and organisation needed for the Super Tuesday campaign. Current Iowa polls show Mike Huckabee ahead with 33 per cent, Mitt Romney second with 27 per cent, and John McCain third, with 10 per cent.

Six weeks ago none of the political commentators gave Huckabee any chance. He was just an obscure ex-Governor of Arkansas. His surge in Iowa seems to have been due to the contrast between his folksy style and his values as a Baptist preacher and the more patrician image of Mitt Romney, the Mormon billionaire. Iowa is in the Bible Belt but does not have many Mormon billionaires.

Among the Republicans the national lead runner is still the former Mayor of New York, Rudy Giuliani. He has made no effort to campaign in Iowa, which was a mistake. After Iowa, there will probably still be four Republicans in the race, Huckabee, McCain, Giuliani and Romney. Romney, who has spent an indecent amount of money on attack advertising, seems to be fading; Giuliani, currently on 7 per cent in the Iowa polls, is also slipping. Both so far have had a bad Iowa.

The exciting race is that of the Democrats. Nationwide, Hillary Clinton is the leading candidate, with 44 per cent to Barak Obama's 25 and John Edwards's 13; in Iowa, the race is much closer — Clinton 29 per cent, Obama 27 per cent and Edwards also 27. Any of the three could win the Iowa caucuses. There is no dark-horse candidate, with the possible exception of Bill Richardson, who was the US Ambassador to the United Nations under President Clinton. He has been making thoughtful and well-received speeches and, as a Hispanic Governor of New Mexico, must be a contender for the role of vice- presidential candidate, perhaps on Hillary Clinton's ticket. Foreign policy has played only a small part in the Iowa debate, even after the assassination of Benazir Bhutto.

This is the “Get out the vote” message that is coming from the Clinton organisation: “Our message from now until caucus night is clear: it's time to pick a president and it's a time for a new beginning for all of us. Hillary is the best candidate to stand up to the Republicans and inspire millions to make history in November 2008.”

No doubt there are similar messages going out from all the other organisations, not least Obama's. The race between Clinton and Obama is so close that it could be decided by the weather or the holidays. Mrs Clinton has the larger following among the middle-aged, particularly middle-aged women. Mr Obama has the larger following among the young, though there are certainly matrons for Obama and students for Clinton. Iowa last week was deep in snow and threatened with blizzards; elderly people could not dig their way to their own front gates, let alone get to the caucus rooms. The weather forecast for the coming week is bright and sunny.

Equally, many students take their holidays — sometimes to go skiing — over the new year. Iowa State University does not reopen until January 15, though the dormitories will be opened for three days over the caucus period. Policy wonks may fly back to caucus for Obama but skiing buffs will not. Such narrow differences could tip the scale.

On the Democrats side, the United States is already moving towards a two-candidate race for the presidential nomination. Barring catastrophe, Hillary Clinton should be ahead or level in Iowa, ahead in New Hampshire and should virtually win the nomination on Super Tuesday. But Barak Obama is a strong candidate who matches Mrs Clinton's experience with his message of hope.

The Republicans have not yet found a candidate with any obvious capacity to win. The early front- runners, Giuliani and Romney, now seem to have negative momentum — they're going backwards. If the Republican race ends up between Huckabee and McCain, I would support McCain, but I would, perhaps mistakenly, expect Huckabee to win. Yet a presidential race in November between Mike Huckabee and Hillary Clinton could, I think, have only one result, and it would not be a Republican victory.

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