Sharrell Shields speaks for many African Americans when she says she's starting to believe Democrat Barack Obama is going to be the next US President - but a certain skepticism keeps her hopes in check.

While some polls show Mr Obama, who would be the first black president, has opened a double-digit lead over Republican John Mr McCain with just three weeks to go before the election, generations of slow and sometimes stalled steps toward racial equality have left some blacks wary of disappointment.

"I'm about half and half right now that he'll win," said Ms Shields, an 18-year-old university student and Mr Obama supporter at a union-sponsored candidate forum in Cincinnati.

"Now when November comes and we're almost there, then I'll believe. Right now, I just have my fingers crossed."Baptist preacher and Mr Obama backer Brenda Girton-Mitchell, 60, said she had enough faith "in the human psyche" to believe that Mr Obama would prevail over Mr McCain.

But she echoes blacks across the country when she notes that polls have fooled them before, citing the famous case of Tom Bradley, an African American who narrowly lost the 1982 California governor's election despite leading in polls.

Mr Bradley's defeat was a surprise and some observers concluded that many white voters had lied about their intentions.

"Very often people are not very honest about race and sexual preferences. They say the politically correct thing," said Ms Girton-Mitchell, interviewed in downtown Washington, DC, during lunch hour.