But political experts say it is doubtful the popular US talk show host can sway votes to fellow-Chicagoan and first-term Illinois Senator Barack Obama, the way she persuades viewers to turn books into instant best-sellers or adopt her self-help philosophy.

“People say that she won’t be able to snap her fingers and have Iowans jump,” said Dennis Goldford, a political scientist at Drake University in Des Moines, Iowa.

“She will help furnish him with an audience of people attracted to her, for him to make his own pitch,” Goldford said. “I think she can sell his books a lot easier than she can sell his candidacy.”

Winfrey’s book club choices have catapulted such tomes as Anna Karenina and The Road to best-seller lists, and her shows featuring serious topics such as child abuse have earned numerous awards, and imitators.

“The back story here is that Oprah knows Obama,” Northwestern University political analyst Reuel Rogers said. “Both are from Chicago, and she’s known him for a long time. As she put it, she can attest to ‘the depths of his moral authority.’ It’s a very distinct personal relationship. It makes me wonder if she got to know the other candidates, maybe she’d feel that way about them.”

Three-quarters of the 8.6 million viewers tuning in to Winfrey’s show are women, and she reaches 46 million unique viewers each week. More than half are over 50 years old, and older people are more likely to vote.

Any voters put off by Winfrey and Obama both being black would be unlikely to vote for Obama anyway because of his race, Rogers added.