"John Kerry may be wooden, but he's at his best in a fight"

John Kerry thinks he knows the Australian accent pretty well."Oz-TRY-le-an," he says with emphasis as we meet mid-air aboard his Boeing 757, modestly emblazoned"John Kerry President". Half an hour earlier we'd raced out of Denver, Colorado, our police motorcade ablaze in blue and red. Now we should be heading south for New Mexico, where more voters wait to be wooed. But instead of another stop on the trail Kerry hopes will end at the White House on November 2, the jet's nose suddenly points east to Washington DC, where the Republicans are planning an ambush in the Congress.

It's been a long day for the 60-year-old Democrat and his growing entourage. He left Nantucket on the north-east coast at 6am, reached the Rocky Mountains by mid-morning, and now, after a day's campaigning, he's due in the nation's capital at 2am. Total distance: about 6300 kilometres.

After a few hours' sleep, Kerry will be stalking the ornate corridors of the Capitol, making a rare return to his Senate duties to vote on a bill vital to one of his key constituencies - Vietnam War veterans. All the time he's thinking - about money, policies, a vice-president. Clearly, he has a lot going on. For the moment, though, he looks relaxed as he wanders out from his curtained compartment.

An aide introduces us."Oz-TRY-le-an," Kerry says. But when I suggest he picked up the accent on an R&R trip to Australia during the Vietnam War, there is no response. Instead, he heads back to his compartment.

It's a strange moment: Kerry has given a firm handshake, smiled, registered my nationality, made a mild joke about it, and then completely switched off. He hasn't been unfriendly. He hasn't been aloof - the most common criticism of him. He's just tuned in for a second, then disconnected. He knows I can't win him a single vote.

Backtrack 18 months to an icy Washington evening in January 2003 - a night for indoors, for politics and plots. At the White House, George W. Bush is mulling over a speech that will set the US on course for war in Iraq. Across town at a swank city hotel, six men attack him relentlessly as they begin manoeuvring for his job. One of them towers above the rest, still slim at six foot four (193cm), still good for the odd ice hockey game or a scoot across the waves on his windsurfer. Big-headed with a thicket of greying hair and a lantern jaw, he has a slightly melancholy look. His voice is deep, his tone serious. The message is clear: I'm presidential material - just look at my initials. JFK.

This is John Forbes Kerry, the widely travelled, well-educated son of a diplomat; Kerry, the decorated war hero whose anti-Vietnam campaign rattled the Nixon White House; Kerry, the four-term Massachusetts Senator who speaks French and specialises in foreign policy; Kerry, the guy who married one of America's richest women....