For the man who has brought rock-star charisma to electoral politics, today saw the campaign rally as pop festival, a summer gathering of peace, love — and loathing of George Bush.

Taking what he calls his "improbable journey" to the heart of Europe, Barack Obama succeeded in closing down one of Berlin's main thoroughfares tonight, luring the city's young in their tens of thousands to stand in the evening sunshine and hear him spin his dreams of hope, not for America this time, but for the whole world.

The young and the pierced, some with guitars slung over their shoulders, others barefoot, jammed up against each other to cheer on a man who in less than a year has become the world's most popular serving politician, even

if, as yet, he has been elected to no office grander than the junior Senate seat for Illinois.

Expectations had been impossibly high, with predictions of a million-strong crowd filling the Strasse des 17 Juni, the wide avenue that links the Brandenburg Gate with the looming, gold-topped Victory column of the Siegessäule.

The candidate himself had sought to lower expectations, telling reporters on the plane from Tel Aviv that he doubted he would be greeted in Berlin by "a million screaming Germans".

Once the Glastonbury-style warm-up bands and DJs had quieted, the Democratic nominee almost floated into view, walking to the podium on a raised, blue-carpeted runway, as if he were somehow, magically, walking on water. Even from a distance, the brilliant white of his teeth dazzled.

It was a reminder that the latest edition of Stern magazine features Obama on the cover, above the line "Saviour — or demagogue?"

The speech was not one of Obama's masterpieces, but it certainly cleared the exceptionally high standard he has set himself. Poetically, he reminded Berliners of what they would surely regard as their finest hours, their resilience during the blockade some 60 years ago — when the Soviet Union tried "to extinguish the last flame of freedom in Berlin" — and the fall of the wall in 1989, an event which opened the "doors of democracy" all over the world.

But the loudest applause came when Obama, however subtly, offered himself as the coming antidote to all that Germans, Europeans, indeed most non-Americans, have disliked about the Bush era.

After listing a series of global problems, from genocide in Darfur to loose nukes, he declared: "No one nation, no matter how large or how powerful, can defeat such challenges alone." It was a promise to end the unilateralism of the early Bush years, and the crowd could not contain their delight.

There was no less warmth when Obama explained his belief in "allies who will listen to each other, who will learn from each other who will, above all, trust each other".

Again and again he uttered sentences that could never have come from the mouth of George W Bush, and Berlin could not have been more grateful.

"This is the moment to secure the peace of the world without nuclear weapons," he said. On Iraq, the aim was "to finally bring this war to a close". He asked if today's generation was ready to seize the moment that was at hand. "Will we reject torture and stand for the rule of law?" he asked. "Will we welcome immigrants from different lands?"

As for the threat of climate change, he spoke in language that could not have been more sweeping or more epic: "This is the moment we must come together to save this planet." (Was that saviour or demagogue — or both?)

He didn't spell out that he would reverse much of the course of the last eight years, but that was only because he didn't have to.

"This is an anti-Bush rally," said one man, an employee of the German government, reluctant to reveal his name because of his job.

The last time he had seen such a crowd in the same place was for the Love Parade music festival, "and you can see the similarities", he said. There was only one dissonant note, but Obama's mood music covered it nicely.

Invoking the spirit of the airlift of 1948, he called for there to be more "sharing the burden" between Germany and America, code for his request for Germany to send more troops for the Nato mission to Afghanistan. "We have too much at stake to turn back now."

Germany's politicians had given their response to that earlier in the day, with Chancellor Angela Merkel telling the candidate there were "limits" on how many troops Germany would send. The move came after the German cabinet had voted to increase the number of troops from 1,000 to 4,500.

Overall, though, the mood was warm, even joyful, a sign perhaps of just how deep the yearning outside the US is to end the current era — and to have an America non-Americans can believe in again.

Andreas Wernicke, 27, a computer salesman, said the idea of an African-American US president was "just totally cool", if it happened, he said, "you could tell yourself that, yes, the world does advance".

By common consent, tonight and the entire Obama week has been a huge success, generating priceless images for TV consumption back home and helping Obama cross the credibility gap — making it easier for Americans to imagine him as a player on the world stage.

The Obama camp is hoping the notion that the US will regain the respect of the world under a President Obama will persuade many American voters to back him.

Tonight's pictures from Berlin will have further discomforted Obama's Republican opponent, John McCain, who has struggled for media oxygen during a week of near-constant coverage of the Democrat's grand tour.

He complained on Fox News yesterday that he was barely getting a look in. "All I can do is be amused," he said manfully.