So it’s now official, and 80,000 packed into the Denver Broncos’ football stadium in Denver on Thursday were there to see it: Barack Obama is now indisputably the Democratic candidate for the 2008 presidential election campaign, and the first bi-racial man in American history to win the nomination of a major party. The unlikely campaign that began 19 months ago in the freezing winter of Springfield, Illinois had reached and passed its penultimate hurdle.
Senator Obama himself, revelling in the biggest political extravaganza the US has ever seen, seized the opportunity on prime-time, coast-to-coast television to switch gears in campaign strategy - and the nation witnessed non-confrontational Obama morph into combative Obama.
"If John McCain wants to have a debate about who has the temperament and judgment to serve as the next commander-in-chief, that's a debate I'm ready to have," he roared with the characteristically brilliant, soaring oratory that has stirred so much enthusiasm across the world. "I've got news for you, John McCain. We all put our country first... John McCain likes to say that he'll follow bin Laden to the gates of hell, but he won't even go to the cave where he lives."
McCain, meanwhile, also took advantage of the evening to spring a surprise, one-upmanship campaign ad on the nation’s television screens. Oozing supposed sincerity, McCain looked straight into the camera and congratulated his opponent: "Senator Obama, this is truly a good day for America," he said. "Too often, the achievements of our opponents go unnoticed." Minutes later, viewers saw an Obama campaign ad featuring a negative personal attack on McCain - all with the overall effect that Mr Nice Guy seemed to have transformed into an attack dog during the course of the evening, while the veteran old toughie McCain had changed into the warm and fuzzy of the two candidates.
All of which is to say it was a thoroughly political, highly calculated evening. To make certain the 80,000 seats in the stadium were filled, the Obama campaign had distributed 20,000 more tickets to supporters than there were seats - leaving many who had waited for hours to get through secret service security fuming that they were unable to get into the stadium for the big moment.
In fact, they had already missed a monumentally choreographed event in which entertainment and politics became inextricably intertwined: the likes of Sheryl Crow or Stevie Wonder were entertaining the teeming thousands in the so-called "mile-high" stadium one minute, Al Gore and Joe Biden thundering away the next.
No longer was there any pretence that American politics has not merged imperceptibly with entertainment and showbiz, sometimes making it hard to distinguish between them. I gather it will be somewhat similar at the Republican convention in St Paul, Minnesota that begins on 1 September - except that it will be country music entertaining the Republican masses, and the convention will intentionally and conspicuously be much less of a spectacle.
That is why the dramatic final day of the Democratic convention, perfectly timed to co-incide with the 45th anniversary of Martin Luther King’s "I Have A Dream" speech, was something of a risk for Obama - that it could re-enforce Republican attacks that he is all show and no substance. His speech, partly a shopping list of all the positive things an Obama administration would do - delivered, as ever, in spectacular fashion - was intended to pre-empt such charges.
Inside the stadium, though, there was much genuine emotion. Journalists abandoned any show of impartiality by joining in the party, with CNN’s main anchorman getting up and dancing (off-camera) with an Obama strategist to the strains of Stevie Wonder. More touchingly, the likes of 68-year-old Representative John Lewis - the only surviving, still-active member of Martin Luther King’s inner circle - repeated remarks by many African-Americans during the evening, that they never thought they would live to see the day when a black man was nominated by a major party to be president.
I wonder. I just hope they’re right that a major racial rubicon has been crossed with Obama’s nomination, and that it is not wishful thinking that African Americans have now gained political equality with whites. But would America be ready to nominate a younger John Lewis, say, whose skin is much darker and whose ancestors were slaves - like nearly all African Americans? Because Obama is half-white, did not have ancestors who were slaves, and did not have an economically underprivileged upbringing, he is far from being an ideal representative of America’s still-repressed black population - and a man whose style and manner is very different from the likes of Lewis and other highly respected African-American politicians of all ages who have never come remotely close to being seen as potential US presidents.
Obama is unquestionably one of America’s greatest-ever political orators, though, and Thursday night’s speech encompassed a touch of JFK here, a dab of MLK there, with bits of Lincoln thrown in for good measure. Fireworks exploded from a mock Roman coliseum to mark the end of his acceptance speech as Michelle Obama and their two daughters, aged 7 and 10, joined Obama on stage and dodged the confetti raining down on them.
But now it’s straight back to politics as usual. Polls still show Obama only very slightly ahead of McCain, worryingly for the Democrats; Rasmussen's Thursday daily tracking poll, taken before the extravaganza from which Obama should be able to expect a bounce, had them tied. The presumptive Republican candidate will unveil his running-mate on Friday, hoping to upstage Obama’s acceptance speech coverage and steal some of his spectacular thunder. In the words of McCain’s Thursday night’s surprise lovey-dovey ad, “Tomorrow, we'll be back at it.” He can say that again: by the time McCain is officially enthroned by the Republicans at their convention next Thursday, real battle will have commenced. And much blood, I predict, will then be spilled.