Oprah Winfrey brought her star power to Iowa on Saturday, telling thousands of Barack Obama supporters that the senator would lead the U.S. with honour and compassion.
It's the first time in Winfrey's career that she has publicly endorsed a presidential candidate, let alone take part in a campaign trail.
"I am not here for partisan beliefs. Over the years, I've voted for as many Republicans as I have Democrats," Winfrey said during a speech in Des Moines.
"This isn't about partisanship for me. This is very, very personal. I'm here because of my personal conviction about Barack Obama and what I know he can do for America."
Senator Obama is hoping the "O factor" will give him an edge over his main Democratic rival, Senator Hillary Clinton.
Winfrey's book endorsements have been known to create instant best sellers, and political analysts suggested she may have a similar effect on Obama's popularity -- although she poked fun at the comparison on Saturday.
"Despite all the talk, speculation and the hype, I understand the difference between a book talk and this critical moment in our nation's history," she said.
Thousands of Iowans offered up their time as campaign volunteers in the hopes of scoring tickets to see Winfrey appear with Obama in Des Moines and Cedar Rapids.
Volunteers were guaranteed a ticket if they completed a four-hour volunteer shift or attended local caucus training before the event, a news release said.
"The only other universally adored person coming to Iowa this December is Santa," Obama's Iowa press secretary Tommy Vietor told The Associated Press.
Field assistant Prianka Sharma, 22, spent the week distributing blue priority tickets and white general admission tickets.
"Everyone who comes in will get a ticket -- the number will just depend on their involvement with the campaign," she said.
"Even if they are supporting other campaigns, we'll give them one."
The media mogul will also lend her star power to events in Columbia, S.C. and Manchester, N.H. on Sunday.
The South Carolina event was moved to an 80,000-seat university stadium after the original 18,000 tickets offered were snatched up quickly.
The queen of daytime TV publicly threw her support behind Obama earlier this year.
In September, Winfrey rolled out the red carpet for the Illinois senator during a fundraiser, netting US$3 million for his campaign.
Obama is engaged in a tight, three-way race with Hillary Rodham Clinton and John Edwards, with the Jan. 3 caucuses less than a month away.
Clinton is firing back with her own high-powered endorsement by enlisting the help of her husband, former U.S. President Bill Clinton.
With files from The Associated Press
