Chicago - Democratic presidential nominee Barack Obama may have been raised largely by his white grandparents in distant Hawaii, but when he wanted to connect with his community as a black man he came to Chicago.

Now with the White House in reach, Obama is returning to Chicago on Tuesday to mark election day in the city where his rise to prominence began. City officials expect up to a million people could gather in Grant Park to watch election results and hear from Obama after votes are tabulated in his race against Republican John McCain.

Though polls show the Democrat ahead, McCain's down-to-the-wire campaigning has taken aim to key swing states that could push him over the top in the state-by-state winner-takes-all electoral college.

But in largely Democratic Chicago, voters will throw their support behind Obama and much of the fervour behind his candidacy here will come from his fellow African Americans, driving in part an expected 80-per-cent voter turnout rate.

The city has had a thriving African American community since blacks first began migrating from the South driven by restrictive segregation and the prospect of jobs in northern manufacturing hubs. In Chicago, which is now 35 per cent black, most settled in the South Side near to industries in areas that had once drawn immigrants from Ireland and Eastern Europe.

Obama began his public career as a community organizer in an impoverished area of the far South Side and now African Americans from all socioeconomic backgrounds - from grafitti-scarred housing projects to Hyde Park mansions - see him as one of their own.

"If nothing else it's been a sign of motivation for people on the South Side to see someone different as president, who happens to come from a similar background on the South Side of Chicago," said Allen Linton II, a 19-year-old political science student at the University of Chicago who has been working to get out the vote among his fellow African Americans in those neighbourhoods.

Linton, clad in an Obama T-shirt and baseball cap and studying outside on an unseasonably warm Chicago day, said those efforts have focused largely on convincing voters that they have something at stake in the election.

African Americans across the city see Obama's candidacy as a sign of progress in a country marred by the legacy of slavery and segregation, but like most US voters, regardless of race, the economy is foremost on their minds as they head to the polls Tuesday.

"Ninety-eight per cent is about the economy - the price of gas, the price of food, the price of living in general," said T Allen as he loaded his laundry inside a laundromat. The African American senior citizen declined to say whom he voted for, but noted he had supported former first lady Hillary Clinton in the primaries. "You look at their point of view. Race isn't a factor."

Mike Kruglik, 66, a community organizer for the Gamaliel Foundation, has known Obama since the 1980s when they worked together in the South Side.

"Nobody asked me if I thought he'd be president, but I'd had said it wouldn't have surprised me," he recalls looking back on those days.

After travelling across the country to organize volunteers for the candidate, Kruglik believes that concerns that racism will hamper Obama will be outweighed by the country's economic woes.

"Since the beginning of this race, the question has been do they care more about their personal economic success or their racial hangups," he said ahead of the vote.

Even if Obama loses, many point to his candidacy alone as a breakthrough for blacks who never though they'd live to see an African American come this far, just over 40 years since the Civil Rights movement led to desegregation of public facilities and federal guarantees of African Americans' rights.

The advances are especially poignant for Nadine Kijak, 54, who grew up in Mississippi where as a child she longed to visit a local park to see its goldfish pond but was not welcome. She recalls how her father allowed her to briefly frolic on a beach designated for "whites only" although it was against the law.

Kijak never thought she would see a black candidate on a presidential ticket.

"It's inspiring to believe young black boys can see they can be president," she said. (dpa)