When he needed an infusion of campaign cash, she threw a star-studded fundraiser last summer at her California estate. When he needed a big-name draw in the early-primary states, she addressed massive crowds in Iowa, New Hampshire and South Carolina.
And when Obama was looking for a late boost in a critical Super Tuesday state, Winfrey was once again there for him, giving up her Sunday afternoon for a Los Angeles rally.
But as Obama faces his most crucial primary day in months and struggles to move past the Rev. Jeremiah Wright controversy, Winfrey is far from the campaign trail, appearing more focused on sweeps — not election — season.
Indeed, since Super Tuesday on Feb. 5, Oprah has been absent from Obama's side. Her people say other projects have kept her too busy to hit the hustings for the candidate. His people say they’d love to have her but don’t need her help in attracting crowds anymore. Either way, people expecting to see her on the stump anytime soon may have to hold their breath longer than David Blaine did this week on her namesake talk show.
Yet it would seem like the perfect time for Obama to call in his super surrogate, considering the next two states up for grabs: North Carolina has a significant African-American population, and Indiana shares a border and a media market with Illinois, where Winfrey resides and tapes her talk show.
Oprah could be an important asset, said Jennifer Duffy, an analyst with the nonpartisan Cook Political Report. In North Carolina, she could act as a counterweight to a Clinton ad featuring Maya Angelou and reassure African-American voters after the Wright controversy (even though she has reportedly attended services at Trinity United Church of Christ in the past). In Indiana, she could appeal to white working-class women.
"It would be very helpful," Duffy said. "Part of the problem is she is not somebody who can drop everything. In some ways, it might be easier to rearrange George Bush's schedule than Oprah Winfrey's schedule."
That’s exactly the point made by the Winfrey camp.
"She doesn't have anything planned at this time," said a representative for Harpo Productions. Winfrey "still strongly supports Obama," but "her business commitments have kept her schedule full since February."
Winfrey is currently shooting new programs through May sweeps, which stretches from April 24 to May 21.
Obama spokeswoman Jen Psaki said they understand that the campaign values her help and wants more of it but that it was not likely until the general election. Psaki suggested the campaign needs to decide when is the best time to tap its surrogates, particularly one as coveted and recognizable as Winfrey.
At this late stage in the primary campaign, Obama no longer needs help attracting thousands of people to an event. His challenge now is proving his policy credentials and personal appeal to constituencies that have favored Sen. Hillary Rodham Clinton, spending the last two days in Indiana in small forums with working-class families, senior citizens and farmers. The image he's trying to project is more Terre Haute than Hollywood.
Yet it’s also true that Oprah’s rare foray into politics proved controversial among certain segments of her largely female fan base, leading to speculation that her absence from the trail reflects a conscious decision to dial back her involvement for reasons other than business projects. After all, the scale of her media empire suggests Winfrey is rarely without pressing business commitments.
When asked about it Friday in Indiana, Obama downplayed the suggestion that Oprah’s popularity has declined because of her involvement with his campaign.
“Oprah’s a dear friend — she’s got a lot of stuff going on, we’ve got a lot of stuff ging on. And as I made clear even at the beginning, her endorsement and other celebrity endorsements can be useful in getting people who aren’t otherwise paying attention to politics to engage, and so that was particularly important in a place like Iowa at the beginning of this campaign,” he said. “I think everybody right now knows there’s a big contest going on and everybody’s paying a lot of attention. And in fact the presidential campaign is probably getting more attention than just about anything else, and so the utility of having a celebrity come with us is probably less now than it was earlier.”
According to a Fox News/Opinion Dynamics poll released after her three-state campaign tour with Obama in December, Winfrey's favorability rating dropped to 55 percent, down from 68 percent in September.
Winfrey's website lit up with criticism, too. One writer called her a "traitor" for not supporting the first viable female presidential candidate, setting off a heated debate on her comment boards among her critics and supporters.
But by the one measure that truly matters — Nielsen ratings — Winfrey does not appear to be suffering.
In the six-month period in which Winfrey's advocacy was at its height — from September to February — her TV ratings registered no sharp increases or declines.
It is "impossible to attribute any change in Oprah's ratings to her support for Barack Obama," said Robert Seidman, co-founder of the website TVbythenumbers.com, which charts the ratings of popular television shows.
Winfrey started her big Obama push Sept. 8 with a fundraiser at her estate near Santa Barbara, Calif. Her Nielsen ratings for the week of Sept. 10-16 came in at 7.63 million.
In mid-November, her ratings were 8.02 million.
By February, following her last public appearance in support of Obama at UCLA with Michelle Obama, Maria Shriver and Caroline Kennedy, Oprah's TV ratings came in at 7.92 million and then topped 8 million again by March.
In April, well after her last high-profile Obama appearance, her ratings dipped to 5.98 million — but so did the ratings of other syndicated shows, such as "Wheel of Fortune."
"Just as I attribute none of 'Wheel of Fortune's' decline to Pat Sajak's political affiliation, as an analyst I don't think people checked out of Oprah because she supports Barack Obama," Seidman said. "The seasonal trends for everything across the board are down."
Donna Bojarsky, a political consultant who works closely with celebrities and the Democratic Party, says she sees nothing unusual in Oprah's absence from Obama's side.
"She's just busy," Bojarsky said.
Noting that Winfrey hasn't endorsed candidates in the past, she said there's a benefit to keeping her appearances "highly valued and rare."