After an epic five-month battle that has transformed American politics, Barack Obama claimed the Democratic nomination last night, continuing his extraordinary quest to become the first African-American president in his country's history.
It was the most important milestone yet, in the meteoric political journey of Mr Obama, the son of a black intellectual from Kenya and a white anthropologist from Kansas who only four years ago was an almost unknown state senator from Illinois.
He finally vanquished Hillary Clinton in a campaign to lead the Democratic Party into battle against John McCain - a campaign that has transformed the political landscape of America by energising tens of millions of voters demanding radical change in Washington and an end to the excessive influence of lobbyists over the machinery of government.
"You chose to listen not to your doubts or your fears, but to your greatest hopes and highest aspirations," he told a delirious victory celebration for 17,000 supporters in a sports arena in St Paul, Minnesota. Another 15,000 gathered outside the arena and in nearby pubs where a "primary happy hour" carried on into the night.
"Tonight, we mark the end of one historic journey with the beginning of another," he said, declaring that without nuance or hesitation he would carry the flag and oust the Republicans from the White House.
"Tonight, I can stand before you and say that I will be the Democratic nominee for President of the United States," he said.
Mr Obama acknowledged he and Mrs Clinton "certainly had our differences this past 18 months" but praised her desire to improve the lives of ordinary Americans.
"And you can rest assured that when we finally win the battle for universal healthcare in this country, and we will win that fight, she will be central to that victory," Mr Obama said.
"Our party and our country are better off because of her and I am a better candidate for having had the honour to compete with Hillary Rodham Clinton."
A last-minute flood of support from Democratic superdelegates and a split result in the last two primaries in Montana and South Dakota, gave Mr Obama the necessary 2,118 delegates to claim the nomination at the Democratic Party's convention in Denver in August. He paid generous tribute to Mrs Clinton she was warmly applauded by the audience, an indication that at least one side the bitterly divided party is ready to move on.
But even in defeat Mrs Clinton was not prepared to leave the race just yet. While she too paid tribute to her opponent, saying "It has been an honour to contest the primaries with him, just as it has been an honour to call him my friend". She also said: "This has been a long campaign and I will be making no decisions tonight."
Rather than bow to the inevitable and unite the party against the common enemy, Mrs Clinton declared to an audience in New York that she was the stronger candidate and had won more votes than Mr Obama.
"I want the 18 million Americans who voted for me to be respected," she declared to raucous cheers.
Mr Obama made his announcement in St Paul, in the very venue where Republicans will crown Mr McCain their nominee in September, a clear message that the general election has already begun. It was his moment also to focus his divided party on the challenge of beating the Republicans in November.
The signals from the Clinton camp were mixed all day. The most intriguing report concerned a conference call with congressional colleagues during which she said she was "open" to being Mr Obama's vice-presidential candidate if it would help the party's chances. In reviving the "dream ticket" speculation, the former first lady appeared to be coming to terms with the fact that her own personal dream of returning to the White House as President was over.
It was a mostly doleful crowd of supporters who gathered in a basement gym of a college in Manhattan last night to hear her own response to the day's dramatic events. There was no longer disguising reality. This will not be the election that delivers the first female Commander-in-Chief to the Oval Office.
Mr Obama waited for the last primary results to come in – five months to the day from when the contest opened – superdelegates who have remained neutral in the Obama-Clinton struggle began jumping to his side. The most important of these were South Carolina's James Clyburn, the most senior black politician in the House of Representatives, and the former president Jimmy Carter.
The superdelegate flow started with a trickle in the morning, gathered pace and became a flood by evening. A California congresswoman, Maxine Waters, even switched from Clinton to Obama, saying, "Now is the time for us to unite so that real change is possible in November".
The presidential campaign quickly moved to a new phase as Mr McCain bickered over the airwaves with Mr Obama's claim that a McCain presidency would be a rerun of George Bush's policies. Speaking in Louisiana Mr McCain put distance between himself and Mr Bush while dismissing Mr. Obama as a greenhorn politician.
"The American people didn't get to know me yesterday, as they are just getting to know Senator Obama," Mr. McCain said.
The fierce and sometimes ugly struggle between the first black candidate and first woman with a solid shot at the White House has already earned a unique place in the history of US politics. It was the most costly, the most competitive and the greatest in terms of voter enthusiasm and registration. But it arguably also damaged the Democrats' chances of victory in November, by fanning the flames of racial prejudice against Mr Obama.
America's university-educated elites as well as black voters have been dazzled by his unflappable style, thoughtfulness and rhetorical flair. But he remains an elusive figure for many white working-class Americans. This could be dangerous in the swing states of Ohio and Pennsylvania, where Mr McCain can be counted on to deploy the narrative of his military service.
Meanwhile, most of Mrs Clinton's campaign staff are being released, and paid only until 15 June. Her tone has become far more conciliatory. Her aides have made clear they will accept the outcome of last weekend's rules committee decision to award her only a small majority of the delegates from disputed primaries in Michigan and Florida.
Whatever the public posturing, the most important decisions will be taken behind the scenes, as the candidates and their aides work out the choreography of this astonishing campaign's denouement, and lay the groundwork for a united convention.
Feelers to that end are already out. Mr Obama has said he is ready to meet Mrs Clinton at the place and moment of her choosing. In these talks, her future role will be settled.
Dick Morris, the former Clinton adviser turned political enemy, warned that Putting Mrs Clinton on the ticket for vice president would create a ménage-à-trois. "Bill will be the unexpected roommate. Even if a President Obama can discipline Hillary and get her to play second fiddle, there is not the remotest chance that he can get the former president to accept such rules."
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