More than a third of all white Democrats agreed with at least one negative adjective about blacks, raising the question of how much racial misgivings could count in the presidential race if the election is close, according to an Associated Press/Ipsos poll conduct Aug. 27-Sept. 5.

But the poll also found other non-racial factors contributing to Barack Obama's difficulties in breaking away from opponent John McCain.

AP says the poll's statistical model indicates that Obama's support could be as much as 6 points higher if there were no racial prejudice. Among the third of white Democrats who agreed with at least one negative adjective, 58 percent said they would vote for Barack Obama.

"There are a lot fewer bigots than there were 50 years ago, but that doesn't mean there's only a few bigots," said Paul Sniderman, a political scientist at Stanford University with whom the poll was conducted.