A moment in a Florida gym last week got me thinking. As we doomed men and women toiled sweatily away on treadmills and ellipticals (has anyone ever thought of hooking all these machines up to the national grid?), overhead jumbotrons brought us the news from America. As ever these days each screen - CNN, Fox or MSNBC - depicted two to three stories simultaneously, No1 based in the studio, a related No2 tale in the form of large graphics, and a series of third stories running in a ticker-tape strapline at the bottom.

On this occasion story No1 was - as it is a quarter of the time here - about health and dieting. Over some cheesey doctor giving out the latest dope on how to survive affluence, there was a big graphic asking: “What is the best way to lose weight?” But as I glanced up from my calory-counter the retreating strapline, as if answering the higher question, bore the words: “Get circumcised.” “There's a desperate measure,” I thought to myself, before working out that the lower story was probably something to do with reducing susceptibility to Aids.

It was a moment only of confusion as upper and lower stories appeared to mesh, then went on their separate ways. But the same thing also seemed be happening in American politics. Last night the almost universally derided (when he is not ignored) President Bush delivered his final State of the Union. Today the Florida Republican primary has Mitt Romney and John McCain locked in close and unfriendly embrace, while Mike Huckabee - one of those Americans that we Europeans just don't get - and Rudy Giuliani struggle to stay in the race.

Surreally, Mr Giuliani has been prowling Sunshine State synagogues telling the other candidates to be nice to each other, but one presumes his game, like that of the Democrat John Edwards, is now to stay in the race till the summer party conventions. For the first time in 30 years the race could go right on till the end, and - just as a sporting event - that is just so entertaining.

A race like a crackpot Dynasty

The contest between Barack Obama and Hillary Clinton matches any fiction

Multimedia

• Full coverage: US elections

Background

• The ascent of Barack Obama, Mr Charisma

• Decay, jobs and guns fall under the spotlight

• Free trade: Clinton/Obama's mistakes

What it isn't is quite real. The Democrat fuss yesterday was about whether Bill Clinton was being mean to blacks by casually - and strangely - coupling the Barack Obama campaign with that of Jesse Jackson in 1984. The pinhead sensation was the endorsement by the daughter of JFK - himself dead now these 45 years - and his Senator brother, of Mr Obama. Is there anybody still alive, one wonders, who voted for Nixon in 1960? It is never repeated here - as it isn't in Europe - that JFK officially beat Nixon by 0.2 per cent of the popular vote, and that it's quite possible that Nixon in fact won a small plurality of the vote that year.

In campaigns like this, however, myth trumps reality at almost every turn. The imagined America becomes more important than the one that exists. One of the Republican candidates campaigned in Michigan promising to restore the US automobile industry, as though the past 30 years of globalisation had not happened. The Democrats undertake to “end the war in Iraq”, imagining that this objective is coterminous with their pledged withdrawal of American troops. But it obviously ain't. In the cold world of the struggle against terrorism and the conditions that give rise to it, there is now a war in frontier Pakistan by which America (and much of the world) is hugely affected, and in which no US troops are involved.

At the weekend the journalist Christopher Caldwell asked why it was that presidential candidates posed more for photos with factory workers than ballet troupes, pointing out that in real America there were now more choreographers than metal-casters. Yet the image most constantly associated with US economics during the election is the ordinary guy on the line, not the ordinary gal in the office. And while the candidates hit each other over the heads with their own economic rescue plans, traders in Congress and the White House, make bargains over what the real recovery package will look like.

This upper and lower story division is not just an American phenomenon. It is rather wonderful that poor old Peter Hain should have been told to quit - in advance of his actual departure - on the basis that his short campaign to be Labour deputy leader (which he never became) had proved that he was somehow too incompetent to be a Cabinet minister (which he had been for years). I couldn't help feeling that the argument should have been the other way around.

Or there's Ken and Boris. Whatever else that battle has been about so far, it hasn't seemed to touch much on the question of running that huge and important city called London. There's the renewed evidence of what some of us have known for years, that Mr Livingstone is an occasionally very unlovely man, some of whose closest advisers are chosen for their loyalty to him rather than their sanity; there's the piccaninny reminder that Mr Johnson is sometimes self-indulgent and silly. But what would either man mean for Britain's capital? Sorry, that's a lower level story.

So what does the observation of this split mean? One of my American friends - a Barack fan - interpreted my notion as being a subtle attack on Mr Obama. He was wrong, but his sensitivity reminded me that the Obamaniacs are, in this contest at least, the anti-wonks, the painters with the broadest brushes, the makers of delightful myths.

In last week's North Carolina debate, before Mr Obama won his big victory, there was the famous Hillary-Barack bust-up. What didn't get widely reported was the discussion about their plans for US healthcare. Mrs Clinton and Mr Edwards championed a system in which everybody would be covered by mandated insurance. Mr Obama preferred a plan in which there would be no compulsory insurance because he would somehow reduce health costs so much that the poorest would be able and willing to afford healthcare. What he seemed to fail to understand was that many of the poorest people might well calculate, whatever the cost, that they would prefer the cash in hand and risk the chance of ill health.

That, it seemed to me, was a moment when the top story and the bottom story should have come together. Perhaps it still will.

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