WASHINGTON (CNN) -- The impact of a prominent presidential endorsement often fails to resonate at the polls, but popular talk show host Oprah Winfrey's backing of Sen. Barack Obama could prove to have a more significant effect.
Oprah Winfrey may have a larger role in Sen. Barack Obama's presidential campaign.
Winfrey, who first told CNN's Larry King last year she is backing Obama, may assume a visible role in the Democrat's presidential bid, a source close to the Illinois senator tells CNN. She is already slated to hold a star-studded fundraiser at her California estate this weekend.
Winfrey has repeatedly shown her name can sell nearly anything, but the media magnate has never endorsed a presidential candidate before.
It remains to be seen if the popular talk show host's role may go beyond raising money from her Hollywood friends, but the prospect of seeing Winfrey in campaign commercials or on the stump is already causing widespread speculation on the effect she may have. Watch how Winfrey could boost Obama »
"I think what Oprah can do is potentially bring out the congregants of the church of Oprah," Marty Kaplan, a communications professor at the University of Southern California, tells CNN. "She is a charismatic leader of a lay congregation."
"People buy books when she tells them to. They will watch her shows, and buy her magazines when she asks them to," Kaplan added. "So the question is, are enough of them willing to follow her lead not with a consumer good, but with a ballot cast?"
Moreover, Kaplan says, Winfrey's core audience is women, and her endorsement could help Obama compete with his chief presidential rival, New York Sen. Hillary Clinton, for women's votes.
"One of his campaign officials in California told me Oprah is everything," Kaplan added. "So they have high hopes for the endorsement."
Obama and Winfrey's close relationship may also increase the chance she will be willing to take a visible role in the campaign.
"They met way back here in Chicago in the African-American social circuit back in, I believe, either the late 1990s or around 2000 when he was running for Congress," David Mendell, an Obama biographer, tells CNN.
"Obama is very adept at selling himself to people of the elite," Mendell added. "And so, in the last year or so, he has sat down with her and they have struck up this relationship."
Obama's campaign wouldn't elaborate on what role Winfrey may have, but spokesman Bill Burton told CNN, "We are proud to have the support of such an important and dynamic individual." E-mail to a friend