The Magic Touch?

"When you think about Oprah's success in selling books, you can't laugh off the fact that she can sway many, many people," said Donna Brazile, who managed Al Gore's 2000 campaign. "She has a very large following -- and we're talking about people who hang on her every word."

Among the weapons in Winfrey's arsenal: the television program that reaches 8.4 million viewers each weekday afternoon, according to the most recent Nielsen numbers. Her Web site reaches 2.3 unique viewers each month, "O, the Oprah Magazine," has a circulation of 2 million, she circulates a weekly newsletter to 420,000 fans and 360,000 people have subscribed to her Web site for daily "Oprah Alerts" by e-mail.

More than that, though, the Nielsen tracking data show that her most loyal viewers are women between 25 and 55 -- a group that also votes in large numbers in Democratic primaries. National Election Pool exit polling from 2004 showed that women older than 45 represented a third of the electorate in the Democratic primary contests in New Hampshire, Iowa and South Carolina.

How powerful can an association with Winfrey be? On Sept. 19, 2000, George W. Bush trailed Gore in the Gallup-CNN-USA Today poll by 10 percentage points, and struggled particularly with women voters. Then he sat down on Winfrey's couch. They talked about his decision to quit drinking, his love for his wife and daughters, his religious faith and the legacy of being a president's son.

The following week, the same poll showed Bush with a two-point advantage -- a statistical tie. News reports called it the "Oprah bounce."

Winfrey said in an audio Web chat last week that, this year, the Obamas will be her only political guests.

"It would be really disingenuous of me to be sitting up there interviewing other people . . . pretending to be objective," she said.

Winfrey's show is not subject to any "equal time" obligations, because Federal Communications Commission rules do not apply to news programs, interview shows and documentaries in which the candidate is not the sole focus.

Obama's chief rival for the Democratic nomination, Sen. Hillary Clinton (D-N.Y.), will not be completely deprived of a daytime audience packed with potential women voters. She landed a slot on "The Ellen DeGeneres Show" yesterday and will likely be back.

On Tuesday, former president Bill Clinton made an appearance on Oprah. But the talk show host made clear that Clinton had solicited the appearance himself, and they did not dwell long on politics, instead talking about his new book "Giving" and his global good works.

He said his wife had pointed out that she is 15 years older now during her campaign than he was when he ran. "I said, 'Well, nobody made you run, girl,' " Clinton said.

Oprah asked him what his title would be if his wife were to win.