Leading article: How the Democrats made history in Denver

Barack Obama has drawn up his battle lines for November

This week the miracle of modern communications has given everyone who wanted one a ringside seat at one of the most theatrical and exciting spectacles modern politics has to offer. In the case of this year's US Democratic national convention, we were privileged not only to share the thrill of high-flown rhetoric, partisan chanting and placard-waving, but also to witness history in the making and history made.

For the first time, a major US party has nominated a black American for President. This is a milestone whose significance cannot be overestimated, regardless of the result on 4 November. For all the injustices and divisions that persist in American society, it speaks only well of the United States and the Democratic Party that – 40 years after Martin Luther King's words "I have a dream" rang out over the Mall in Washington – the son of a black Kenyan father and a white American mother will contest the most powerful position in the world.

Still more impressive is the way Barack Obama, a first-term Senator from Illinois, set out to campaign from the high ground, without resorting to the narrow prop of race. His was not a sectional campaign. And nowhere was that more evident than in his acceptance speech in Denver on Thursday night. It was a speech in which he sought to appeal to all voters, while answering the whole gamut of his critics. It was conspicuous in making no reference to race before the final paragraphs, and then in only inclusive, not exclusive, terms.

There were those, before he addressed the 80,000-strong crowd at the Mile High stadium, who feared that he had overreached. To hold the convention's closing rally in a sports stadium smacked of hubris – and a desire to claim the Kennedy mantle that invited the response: "You're no Jack Kennedy." The stadium, and the stagey backdrop, seemed to invite the soaring rhetoric that was both Mr Obama's strength and his weakness during the primary campaign.

On the night, though, the Senator triumphantly proved his most severe critics wrong. He filled the stadium and commanded the crowd. He eschewed the sort of rhetoric that fed suspicions of lack of substance and directed some well-chosen shafts against his Republican opponent, John McCain. He can no longer be accused of being "soft" on either the outgoing President or Mr McCain.

How the Republican nominee intends to mount his defence will become clearer next week, as the party's convention proceeds in Minnesota. But the Democrat's choice of Senator Joe Biden as running mate already seems to have boosted Mr Obama's confidence. His boast that sound judgement on foreign affairs, as on much else, could trump a lifetime of poor decision-making also sounds more reasonable and less risky now that Mr Biden is by his side.

If Democrats had hoped to be transported by Mr Obama to another, more ethereal, political zone, they might have been disappointed. In choosing content over form, however, the Senator acted shrewdly. Much remains unspecific, but there was in his speech for the first time the promise of a coherent – and positive – programme for a 21st-century Democratic administration.

It is a programme that presents a real alternative to the Republican agenda of the past eight years, and even in some respects of the new Democrats through the 1990s, with a new role for the state, more than a hint of redistribution and a pledge to end US dependence on Middle East oil within 10 years. This last could facilitate a striking reorientation of US foreign policy.

At the same time, Mr Obama's commitment to tax cuts for "95 per cent of all working families" suggests populist wishful thinking. He will need to come up with a better way of paying for it than a review of loopholes and corporate privileges. It does, though, throw down a gauntlet to the Republicans, if they propose further tax cuts to revive the economy. It also shows that the economy will be as central to this campaign as it was to the Bush-Clinton contest in 1992. And we know what the outcome was then.

These are early days. It remains to be seen whether, or how far, Mr Obama resists the traditional track to the centre as the campaign progresses. Seen from today's perspective, the 2008 presidential race is shaping up to be one of most clear-cut left-right contests for years. That it will also be highly strategic was underlined by Mr McCain's choice of the Governor of Alaska, Sarah Palin, as his running mate. If she can rise to the opportunity and help Mr McCain to tap into the disillusioned vote for Hillary Clinton, she could be a winning choice. If not, her youth and lack of experience could prove a fatal liability.

The selection of Sarah Palin means that all America's sensibilities – age, youth, gender and race – will be in play over the next two months. But, as Barack Obama told his audience in Denver, "it's not about me, it's about you". It is indeed about Americans and how they see their future. This promises to be an absorbing and exciting campaign with no precedent.

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