With Barack Obama on the brink of making history, the Democratic party is taking a calculated risk that Americans are ready to elect their first black president.
In a country where race remains a bitterly divisive issue, most political analysts are reluctant to openly discuss whether Obama's color will prove a handicap to the party's hopes of recapturing the White House.
Primary season polls however clearly show that race remains a huge factor in the electoral landscape, says University of Washington psychologist and political analyst Anthony Greenwald.
Obama's Democratic rival Hillary Clinton defeated him by more than eight percentage points in nine out of 18 primaries, Greenwald said in a study published by the Pew Research Center.
"It is evident ... not only that race is still strongly operative as a factor in America's state elections, but also that its impact depends in substantial part on the racial mixture of the state in question," he said.
Obama directly addressed race in a powerful speech in March, portraying a vision of a nation that might one day be at ease with itself. He has dismissed the idea that his race would play a role in the election.
But in US politics, the phenomenon even has a name -- "The Bradley Effect," named after former Los Angeles mayor Tom Bradley who was defeated in the race for California governor in 1982 even though he was well ahead in the polls.
Many voters told pollsters they had no problem with an African-American governor, but when the votes were counted it was clear they had lied.
"Race is very definitely, part of the white working class vote," Clay Richards, assistant director of the Quinnipiac University Polling Institute, told AFP recently.
"How big a part it is, we don't know," he said. "There are older whites who cannot bring themselves to vote for a black candidate for president."
Even if Obama -- the son of Kenyan man and a white woman from Kansas -- has done better in many states with large African-American populations such as Georgia, South Carolina and Mississippi than the polls predicted, Greenwald remains pessimistic.
"I'm afraid the conclusion is that it's more likely that his race is a liability rather than an asset," he told AFP.
Greenwald added: "Of course he has many assets to go along that liability."
Clinton appeared to be playing up race during the primaries by insisting she would be the strongest candidate to beat Republican John McCain in November, pointing to Obama's problems attracting working class white voters, and saying that only she could can win vital general election states like Ohio and Pennsylvania.
Political scientist Tom Schaller at the University of Maryland however is unswayed by that argument.
Those Americans who can't bring themselves to vote for an African-American are mostly hard-core conservatives, and unlikely to vote for a Democratic president, he said.
"To assume the Bradley effect will apply to him as it has in the past I think is incorrect," he told AFP.
Unlike the Clinton camp, Schaller believes no Democrat candidate can win traditional Republican strongholds in the south such as Kentucky, West Virginia or Tennessee in which the former first lady thumped Obama.
"He doesn't need those states," Schaller said. "He does need Ohio, and there are people in Ohio, and Pennsylvania, and Michigan that may not be able to pull the lever for him.
"The question is whether or not he'll get enough votes from other people to compensate. So he's electable, he has to thread the needle right. But I don't think his race is a disqualifier."
Schaller, who wrote a book arguing that Democrats can win the general election without the southern states, says this "will be the first election in American history where 25 percent of votes will be cast by non-whites."
Among those are Hispanics, who voted overwhelmingly for Clinton in the primaries but are unlikely to vote Republican in November because of McCain's tough stance on immigration.
So Obama has high hopes of winning states in the southwest like Colorado, New Mexico and Nevada, where polls show him doing almost as well as Clinton against McCain.
"There isn't that much drop off, but he does much better (than Clinton) among independents out west who really decide those states," added Schaller.