Queuing in the morning sun for Obama, hoping for a new dawn

Barack Obama was not due until after 1pm but such is the extraordinary excitement surrounding the young Democrat, who looks destined to become the first black President of the USA, they willingly stood for over six hours in the sunshine to be a part of his expected victory.

Black, white, young and old they kept pouring in by the thousands to the rapidly filling square until it had the raucous atmosphere of a carnival. By the time they turned up the R&B music to pump up the crowds, an estimated 60,000 had come.

Mostly the mood was happy, with mothers and fathers singing to the music and stalls selling T-shirts and badges. But there was an unsettling edge, too a tension among people who felt cheated in the 2000 and 2004 presidential elections and who are anxious that it will happen again.

"What are they saying in Europe? Are they saying he'll win or are we going to be tricked out of it again?" a woman asked, clutching my arm while her neighbours took up the cry like a mob.

Later, there were shouting matches with late-arriving TV crews who blocked the view. Reports that police fear riots if Mr Obama is beaten do not seem fanciful.

Nowhere is the contest more intense than in Ohio. It ranges from the rustbelt of decaying heavy industry at Cleveland, a Democrat stronghold, to vast tracts of farmland and old-fashioned small towns that are solidly for John McCain and Sarah Palin. Here in Columbus, the shining state capital, the Democrats dominate the town but the outskirts are Republican. It is the most visited city in America during this campaign, with five recent stops by Mr Obama and a dozen rallies in all.

Finally the music paused and a delighted cheer went up as Michelle Obama walked down the Statehouse steps to introduce her husband. Dressed in a modest yellow cardigan and blue trousers, she was today the dutiful housewife rather than the glamorous lawyer. "When I look at my husband, I know in my heart without a shadow of doubt that he is ready," she said, and the audience chanted back, "Yes he is, yes he is."

And then there was an explosion of yells and cheering as down the steps walked the man everyone had come to see and worship. Mr Obama looked relaxed, though his every nuance was superbly crafted to reassure Americans they could safely vote for him.

Under long protective arms, he shepherded his little daughters, who gaped curiously at the sea of people cheering their daddy. His plain black business suit and crisp white shirt announced that he was a sober policymaker who could be trusted with the nation's finances. But the absence of a tie declared that he was also a man of the people who would not be in thrall to Washington.

"Columbus, I am overwhelmed," he said, hands aloft in the classic politician's pose of mock surrender.

Nine-tenths of his 35-minute address was the speech he has given a hundred times in the past fortnight. Some of the audience even chanted their favourite passages with him, like fans singing along at a rock concert.

In fact, the speech evolves continuously and with one full day left, the Ohio version contained stronger attacks on Mr McCain, perhaps betraying a fear that "the Mac" is catching up. "He's not been a maverick - he's been a sidekick," accused Mr Obama.

He promised tax cuts for "95 per cent of middle Americans". And his website even calculates how much people would save. To the beleaguered car industry, he offered a protectionist umbrella. "We cannot have South Korea shipping hundreds of thousands of cars to the US - that's not right," he said. The crowd yelled back in delight: "It ain't right, it ain't right."

Throughout his performance, Mr Obama accepted the adulation with deep dignity and remarkable composure. Like Bill Clinton and Tony Blair, he is an effortless stage performer who manages to be everyman as well as Superman. "As President I can put more money into schools, but I can't turn off the TV set and make your children do their homework - that's your job," he said, a line that could have been said by Mr Blair or indeed David Cameron.

At least a third of the Columbus audience was black and the significance of a black president to them is incalculable. Sharon Prater, 47, a deputy sheriff who like Obama is of mixed race, said: "There's still people who say we need to know our place. We have to keep on pushing until they realise the world has changed and it is not black or white but that most families are mixed. Barack Obama is the epitome of multi-cultural America."

Annetta Hopewell, 58, spoke of him as a fulfilment of Martin Luther King's "I have a dream" speech. April Whittaker, 40, said regretfully that he surely loses more votes than he gains. "There's a lot of racism. There are many people who will benefit from his policies but cannot bring themselves to vote for a black candidate."

The hopes they have for this brilliant young man are high - and the expectations on his slender shoulders enormous. "It won't be easy," warned Mr Obama, in a passage added to his speech after the economy soured. Few were heeding it. Avoiding defeat tomorrow may well be the least of Barack Obama's challenges. Avoiding disappointment in the tough years ahead may be far, far harder.