racial misgivings could cost Barack Obama the White House in a close election, according to an AP-Yahoo News poll that found one-third of white Democrats hold negative views toward blacks – with many calling them "violent" and "lazy".

The poll, conducted with Stanford University, suggests that the percentage of voters who may turn away from Obama because of his race could easily be larger than the final difference between the candidates in 2004 – about 2.5%.

John McCain has his own obstacles. He's an ally of an unpopular president and would be the nation's oldest first-term president. But Obama faces this: 40% of all white Americans hold at least a partly negative view toward blacks, and that includes many Democrats and independents.

More than a third of all white Democrats and independents – voters Obama can't win the White House without – agreed with at least one negative adjective about blacks, according to the survey, and they are significantly less likely to vote for Obama than those who don't have such views.