The poll responses also show Obama has more work to do to quell fears among voters like Kirstie Hartle of Rome, N.Y., a registered Democrat who has never supported a Republican presidential candidate. With Clinton out of the race, Hartle said, "I'm Republican all the way now."

She said she doesn't like Obama's name and thinks he has a questionable background. She also said she thought Obama was deceitful when he broke from his church after it hurt his campaign, and she doesn't trust him to handle the Iraq war.

"It sounds to me like a Middle Eastern type of name and whether or not he's born here in the United States, he doesn't seem like, to me, somebody who is trustworthy," Hartle said in a telephone interview. "You can't trust anybody these days, so who's to say he's not a terrorist and we just don't realize it yet?"