Thus did Barack Obama claim his victory: "It's been a long time coming, but tonight, because of what we did on this day, in this election, at this defining moment, change has come to America." It is a victory that will go down in US history as the start of a new political age.

Until the Democratic nominee arrived to address the vast crowd in Chicago, having passed the crucial tally of electoral college votes, it had been just possible to believe that victory would somehow elude him; that America had, after all, not been ready for a non-white president, even one as gifted in so many ways as the senator from Illinois. Yet he won, and he won as convincingly and elegantly as he had campaigned.

In so doing, he banished forever the preconception that a black American would never reach the pinnacle of US power. Whatever comes next, America has been transformed. Race will no longer be the indelible stain permeating all social relations. With a black family in the White House, everything will look different: the images, the iconography, America as she sees herself and America as others see her. For all the cruelties and prejudices of the past, it speaks well of the United States that such a victory came to pass – or, as the President-elect expressed it with more poetry, the true genius of America is that America can change.

And impatience for change was surely the message of this election, not just in the long and broad sweep of history, but as a response to a disastrous and mismanaged recent past. George Bush leaves his successor a ruinous legacy: two expensive and unfinished wars, a population on average no richer, and in many cases poorer, than when he assumed office, and a free-market economy so degraded that it had to be rescued from bankruptcy by massive state intervention.

The Bush inheritance was such that it would have weighed down any Republican nominee, and so it did even for John McCain, philosophically the furthest from Mr Bush of all his party's contenders. It is Mr McCain's personal tragedy that he lost to Mr Bush in the malicious primary campaign of 2000. While still a vigorous campaigner, he was, frankly, past his prime when he was finally given his second chance. But he also found himself up against perhaps the most impressive and instinctive politician since John F. Kennedy.

There was a certain wistfulness about the grace with which Mr McCain conceded the Presidency in Phoenix on Tuesday night that suggested both admiration and respect for his much younger adversary. Not that his campaign was faultless – far from it. The selection of Sarah Palin as his running mate, while calculated to secure the party base, lost him the signal advantage of experience and alienated the independent voters who were once his natural constituency. Resort to the sort of attack-dog tactics more associated with George Bush and his neo-con strategists was also unworthy of the man and ceded the high ground to Mr Obama. It was gratifying to see Mr McCain reverting to his former, better, self, as he accepted his defeat. If only he had heeded his better angels all along.

Uplifting campaign

But it is not only the burden of race and the incompetence of the Bush presidency that Mr Obama's victory will, we hope, help to consign to the past. This contest was also a fitting counterweight to the electoral debacle of eight years ago that took Mr Bush to the White House, sapped popular trust in American democracy and discredited the United States around the world.

The 2008 campaign was one of the longest and hardest in recent US history, as well as the most expensive by far. But it was also, thanks to the singular personal stories of the two candidates and their – very different – rhetorical strengths, uplifting in a way none has been since Robert Kennedy's doomed bid to follow in his brother's footsteps 40 years ago. Millions of new voters, young and old, were drawn into the political process. Mr Obama attracted thousands upon thousands to his rallies, and raised millions of dollars in small contributions.

Tuesday's voting, and the early voting that preceded it in many states, with millions prepared to queue for hours to fulfil their civic duty, was proof of how thoroughly US democracy has recovered since 2000. Thanks to McCain v Obama, it is now alive and well, and vigorous, perhaps, as never before. Not only that, but the spirit in which the contest was, for the most part, conducted – with toughness, but also mutual respect and not a little charm – showed politics at its very best.

The only disgrace is that casting a vote still requires so much determination on the part of so many US citizens and tends to be hardest for the poorest. This year's turnout should encourage the authorities to ensure that everyone entitled to vote is able to do so. The provision of adequate polling facilities is fundamental to the smooth functioning of any democracy; a rich country like the United States can have no excuse for failing in this regard.

As Barack Obama and his team prepare for the transition, they command the goodwill not only of a majority of Americans – this was a clear-cut victory – but of millions around the world. And perhaps the greatest danger the new President will face is the pressure from unrealistic expectations. Mr Obama will need all his persuasive powers to manage the hopes he has kindled.

If the past 48 hours are anything to judge by, however, we are looking at a new sort of President, elected by a new, more tolerant and more diverse sort of America. When he promises, as he did on Tuesday night, that a new dawn of American leadership is at hand, he must be given the chance to prove it. In these precarious times, leadership is something Americans, and the Western world, are crying out for.