The Big Mo': How Senator Obama gained the momentum

When the historians come to write about this election they will have to put aside their reference materials and start again, because the power of the movement behind Barack Obama has taken everyone by surprise, not least that master political strategist Bill Clinton.

It is a movement that has generated for the Illinois senator what commentators in the US are calling "the big mo", the extraordinary electoral momentum that he is using to to crush the Clinton operation.

Mr Obama's soaring rhetoric is one factor that conveyed his messages of "change" and "hope". But critical to "the big mo" is also a set of brilliantly effective campaigning skills he honed on the mean streets of Chicago's South Side where he first started out, knocking on doors as a community organiser at the age of 24. Long before seeking elected office, Mr Obama steeped himself in the ways of street agitation and local empowerment and became a master of grass-roots organisation.

The evidence was everywhere in his New Hampshire campaign. At his Manchester headquarters, until the last hours before the vote, volunteers were filing in to pick up their canvassing materials while a phone bank was targeting wavering voters.

Wherever Mr Obama made one of his speeches this week, he began by thanking the army of precinct workers and volunteers who have turned his campaign into a political phenomenon. Mr Obama knows he will need the support of every member of his ragtag army in the days ahead when the Clinton political machine throws every weapon in its arsenal at his political movement.

The Obama campaign knows that the blows will be as low as they are relentless as Hillary Clinton expends what remains of her $100m (50m) war chest in a final attempt to crush her younger but more streetwise opponent.

As she has learnt to her cost in Iowa and New Hampshire, the classic political playbook of carpet-bombing your opponent does not work when the insurgency uses unconventional methods not previously seen in a US presidential campaign.

"We have been preparing for this moment for months," said David Axelrod, the Obama campaign's chief strategist. "We know that we are up against the most formidable political machine of our generation in the Democratic Party in the Clintons. For now the most important thing is our organisation on the ground."

In every speech, Mr Obama takes care to address his volunteer movement as he did again in New Hampshire at midnight in a school gymnasium full of supporters about to vote.

"It's not about me, it's about you," he said, his voice hoarse and ragged. "We will change the mindset that got us into the war in Iraq. We are weary of politics based on spin and PR, and we will be telling the American people not what they want to hear, but what they need to hear."

At the heart of the Obama method is a determination to remain respectful. Whether it is adamant refusal to allow his staff to brief negatively about his opponents or his taking the time to thank those who help him.

The owner of the Baby Boomer fast-food restaurant beside one of his campaign headquarters in New Hampshire described his shock at getting a personal phone call of thanks for all the late-night food he had been providing for his staff. "I can't believe what's just happened," he said. "I got a call from Barack and I thought it was someone having me on."

A generation of black agitators and politicians mobilised the politics of the street and used the raw anger of the ghetto to bring about change in the US. But the way shown by Jesse Jackson and Al Sharpton simply terrified the rest of America.

The difference with Mr Obama is that he is doing it all without anger. The changes he wants to bring about will be just as revolutionary in a country that has witnessed an extraordinary explosion in wealth among the few, while turning its back on the poor and the struggling middle class. But Mr Obama's message of change is somehow not nearly as frightening to corporate America as that of his more populist Democratic rival John Edwards.

Somehow he seems to be telling Americans what they already know about their broken society, and providing a road map to fix it that even Republicans can subscribe to.

Mr Obama's odyssey as a community organiser began at the age of 24 when he said no to a Wall Street career and instead responded to a small ad in The New York Times for a job to get Chicago's numerous churches to start pulling together to help their communities. The tiny organisation he worked for followed the teachings of the radical organiser, Saul Alinsky, whose instruction was to "rub raw the sores of discontent". The Alinsky method is all about winning power rather than seeking to do good and the young Barack Obama became a master practitioner of the method.

But the organisation he worked for, comprised almost entirely of white street agitators, could make no inroads into Chicago's black community. Mr Obama was its front man, going door-to-door, trying to get the city to remove asbestos from public housing, and getting a job database set up in the impoverished South Side.

His breakthrough was to successfully reach out to the mostly black churches of the neighbourhood and to persuade them to work together for change in the community for the first time. He made up for the limitations of street protest by engaging an army of volunteers and often conservative churchgoers.

He joined a church and by 1995 was laying out his vision of the successful agitator politician: "What if a politician were to see his job as that of an organiser, as part-teacher and part-advocate; one who does not sell voters short but who educates them about the real choices before them? As an elected public official, for instance, I could bring church and community leaders together easier than I could as a community organiser or lawyer."

His pastor and mentor was the Rev Dr Jeremiah A Wright. The title of Mr Obama's recent book, The Audacity of Hope, which sets out the need to establish common ground in an age of political polarisation, is based on Dr Wright's more passionate sermon about racial inequality. Mr Obama has taken the fire of the church and the anger of the Chicago street and moulded it into a political campaign based on hope and change. A lot of Democrats are fearful of supporting him because they have seen a similar campaign go up in smoke in the past.

That was the story of the protest campaign of the former California governor Jerry Brown that fizzled in 1992. Bill Bradley also raised Democratic hopes with the delusion that his campaign was above politics, but crashed and burned too, as did the internet-fuelled run of Howard Dean which collapsed in YouTube ignominy in 2004 with his famous scream.

As Mr Obama explained to his supporters this week, the fact that he campaigns on a theme of "hope" (the Clinton campaign has derided him as a "hope-monger") should not be taken for a declaration of unilateral disarmament on the campaign trail. His will be a movement that brings about change in politics, "not from the top down but from the bottom up".

At his New Hampshire headquarters for the past six months, his campaign staffers have been training their "precinct captains" who were in charge of getting out the vote, rounding up Obama supporters all day. On the eve of the vote they had taken over two large rooms in Manchester next door to the probation service. The walls were plastered with maps while the floor was a grid of packages waiting for collection.

They were operating to instructions put together 300 miles away, in Washington DC, where 50 computers have been mining census data and consumer-marketing information to put together what has been described as "the most sophisticated and data-rich portraits of an electorate ever created". It is the work of one of the Democratic Party's top number crunchers, Ken Strasma, whose company Strategic Telemetry helped secure the nomination for John Kerry in 2004. In what seems like ancient political history, Bill Clinton's former pollster Mark Penn invented the concept of the "soccer mom" as the idealised wavering voter to target. In the 2004 race, the pollsters could identify 4x4 drivers as likely Republicans and Prius drivers as convinced Democrats.

The advances the Obama campaign has made can virtually identify the DNA of target voters. It uses something called "micro-targeting technology" to use a range of data everything from income to education to divine whether the campaign should directly target a voter. It is called getting the "demographic DNA" and it has enabled the campaign to make multiple house calls and phone calls to draw in voters.

The secret weapon Mr Obama has brought to his campaign was learnt over years of going door- to-door in Chicago and learning what a corrupting influence the Democratic Party could have at a local level. He also acknowledge that many Americans who want to get on in the world are willing to vote Republican, even if mired in poverty themselves.

Many in the Democratic Party despaired at natural supporters being hoodwinked into voting against their economic interests, and delivering the White House to the Republicans twice in succession. But Mr Obama saw an opportunity to reach out to Republicans, just as Ronald Reagan swept to power on the back of disenchanted Democrats.

One of the loudest cheers he received on the eve of the vote was when he announced that his campaign welcomed Republicans as fellow travellers on the road to bring radical change in Washington. The question everyone now wants answered is whether the political Pied Piper they are following has the staying power to take them through a long struggle with the battle-hardened Clinton political machine.