[cnn-photo-caption image= http://i.l.cnn.net/cnn/2008/POLITICS/05/20/kentucky.democrats/art.split.candidates.ap.jpg caption="Sen. Barack Obama has not had the same success with older, white and blue-collar voters as Sen. Hillary Clinton."]LOUISVILLE, Kentucky (CNN) - Tuesday may end up a big night for Barack Obama, giving him a majority of all possible pledged delegates in the Democratic race for the White House. But exit polling in Kentucky - where CNN is projecting rival Sen. Hillary Clinton will win by a wide margin - suggests that he still has big problems in states with a large majority of older, white and blue-collar voters.
Nearly half of Democratic voters in Kentucky polled Tuesday said they would either vote for Republican Sen. John McCain or not vote at all in November if Obama is the Democratic nominee. Among 1,278 people polled, 33 percent said they would pick McCain over Obama, and 16 percent said they would not vote at all.
By comparison, 76 percent said they would choose Clinton over McCain, with only 17 percent supporting the Republican and 6 percent not voting.