McCain's association with U.S. President George Bush would negatively affect 38 percent of voters casting ballots, the USA Today/Gallup Poll indicated. Thirty-three percent of respondents said Obama's association with the Rev. Jeremiah Wright diminishes the likelihood they would vote for Obama.

However, the Bush-McCain affiliation has more gain than the Obama-Wright association, the poll indicated. Seven percent of respondents said they would be more likely to vote for McCain because of Bush, while 1 percent say they would be more likely to vote for Obama because of his association with Wright.

The poll also asked how former President Bill Clinton might affect voters' likelihood to vote for Sen. Hillary Clinton, D-N.Y. While the 33 percent who say it makes them less likely, 18 percent said they would vote for Clinton because of her husband. Just less than 50 percent say the Clintons' association wouldn't affect their vote, the poll said.

Results are based on interviews May 1-3 with 803 like U.S. voters. The sampling margin of error is 4 percentage points.