Dean pugnacious to the last as defeat looms in primaries

To Howard Dean's impassioned supporters - noisy, numerous and almost electric with excitement at a rally in Tucson, Arizona - it seemed scarcely credible that this could be the end of the road for the man who, more than any other candidate, has set this year's Democratic primary season alight.

Here he was, pugnacious as ever, invoking the New Deal and the civil rights era to tell them they were the crest of a new inspirational wave in American politics. He was the clear, credible alternative to George Bush, he said, not John Kerry, the career senator he dismissed as "the handmaiden of special interests" and "just another inside-the-Beltway guy". (Cue yelps of approval from the crowd.)

The Dean campaign preparing for tomorrow's Arizona primary includes hundreds of volunteers pouring in from California, Utah, Texas and beyond. At the rally, they had their precinct-walking packets ready in upmarket grocery store bags and they soon fanned out over Tucson, walking, driving or even bicycling around neighbourhoods to spread the word.

This looked the polar opposite of a dying campaign. And yet appearances are clearly deceptive: Mr Dean is plummeting in the polls all over the country, Arizona being no exception, and the latest polling data suggests the furious organisational efforts by Mr Dean's loyal army of supporters are making little or no difference.

The frustration was palpable, as volunteers debated whether they could bring themselves to throw their time and energy behind Mr Kerry, assuming he emerges as the nominee, and wondered whether Democratic voters were not making a huge mistake by opting for a political insider who, according to The Washington Post, has accepted more lobbyist money than any other Senator over the past 15 years.

Rick Jacobs, the chair of the Dean campaign in California and a co-ordinator in Arizona, said: "John Kerry is a talented, appealing man, but he has a record as long as the Mississippi river and it's going to be wrapped around his neck by George Bush."

The strategy now is to try to hold on long enough to drive that point home to voters in the big primary states down the road: Michigan, Wisconsin, California and New York. But unless Mr Dean defies the polling numbers, it could be all over for him by Wednesday morning.

The Dean meltdown is proving to be a most bizarre process. For all the rhetoric about his unelectability, his anger and his excessively unconventional campaigning methods, his rivals are all now furiously copying him. He started a political blog, and now they all have one; he led the anti-war charge, and now, with the exception of Joe Lieberman, they are all anti-war, too.

The Dean volunteers pouring into Arizona from out of state also have their imitators. The Kerry campaign, which was a skeletal operation of just nine people until the Iowa caucuses two weeks ago, hastily arranged something very similar, the so-called "Kerry-van" which arrived in Phoenix from Los Angeles on Saturday afternoon to triumphal cries of: "JK all the way!"

The same is true for Wesley Clark, polling in second place in Arizona, whose somewhat militaristic slogan these days is: "Invade a state for Wesley Clark."

But Mr Kerry's surge has upended expectations for several candidates in Arizona, not just Mr Dean.