COLUMBIA, S.C. — Sen. Barack Obama and media tycoon Oprah Winfrey brought their celebrity-endorsement tour to this pivotal Southern state Sunday, drawing thousands -- mostly African Americans and women -- in what Obama called the biggest event of his presidential campaign.
The visit was a test of the candidate's strength in a state that votes Republican in national contests but has a large black population. African Americans make up nearly half of all Democratic voters in South Carolina, and women account for more than half of the state's black Democratic vote.
Winfrey and Obama appealed directly to that demographic, peppering their speeches with "y'all" and "you folks." They made several references to church attendance, beauty parlors and God, and quoted the Rev. Martin Luther King Jr.
Winfrey received the loudest ovation of the hourlong rally when she was introduced by Obama's wife, Michelle, as "the first lady of television." But the Illinois senator had the crowd on its feet several times with promises to end the war in Iraq, confront inner-city poverty and revamp healthcare.
Obama repeated his signature campaign slogan: "Fired up! Ready to go!" The crowd chanted along with him. Thousands cheered as the normally reserved candidate began dancing to a Stevie Wonder tune.
The Obama campaign announced the crowd at 29,000. The number appeared to be slightly lower, with roughly one-quarter of the seats filled in the 80,000-capacity University of South Carolina football stadium.
Whether Winfrey's popularity will translate into votes for Obama in the state's Jan. 26 primary is an open question.
Kevin Griffis, a spokesman for the campaign, said the "Oprah effect," at the very least, means that voters who had not previously paid much attention to Obama had come out to hear his message in person.
Scott H. Huffmon, a political science professor at Winthrop University in Rock Hill, S.C., who has polled the state's black electorate, said Winfrey's presence made Obama "salient" to voters -- even if some people came only to see her and might not vote.
"And a lot are probably already Obama supporters," Huffmon said. "The key to any endorsement, celebrity or otherwise, is winning over people who aren't in your column."
Other political analysts said Winfrey could give Obama a boost in South Carolina as well as the two other states she visited with the candidate over the weekend, Iowa and New Hampshire.
Dick Bennett, a pollster in New Hampshire who is not affiliated with a presidential campaign, said Winfrey's tour came as Obama had cut into Sen. Hillary Rodham Clinton's support among female voters in some states.
Winfrey's message is "take a look at this guy," Bennett said. "I think people will."
Bruce Nesmith, a political scientist at Coe College in Cedar Rapids, Iowa, said Winfrey could help Obama draw more middle-age and older women -- the core of Winfrey's talk show viewership.
Winfrey might also motivate more young voters and others who have not been politically active, analysts said.
A poll of black South Carolinians that Huffmon helped conduct for Winthrop and South Carolina's public TV and radio network found that 35% intended to vote for Obama, 31% for Clinton and 3% for native son John Edwards.
Huffmon said the poll was noteworthy for the 33% of black women who said they were undecided. The poll of 657 people was conducted Sept. 13.
"Black female voters are the crown jewel" in the Democratic primary, he said.
Those voters were clearly a prime target Sunday. Winfrey mentioned the large number of beauty parlors in South Carolina, saying, "We love to keep our hair done, don't we?"
She added, "I know what it means to come from the South," referring to her childhood in Mississippi.
Obama offered a local reference as well, saying, "I married a girl whose people come from South Carolina."
Katrina Franklin, a middle-age black woman from nearby St. Matthews, S.C., said she attended the rally to see Winfrey -- "and Obama as well," she quickly added.
"Oprah is the added attraction," Franklin said. She said she admired Winfrey and Obama because "they're both self-made, positive African Americans."
Franklin said she was leaning strongly toward Obama before the rally but was now certain she would vote for him.
South Carolina is the first Southern state to hold a Democratic primary, three days before Florida.
South Carolina's primary is the first with a significant black population -- 30%, versus 2% in Iowa and less than 1% in New Hampshire. Columbia, the capital, is 50% black, according to the U.S. census.
Winfrey joined Obama and his wife at rallies in Iowa on Saturday and in New Hampshire on Sunday night.
A poll of 400 likely Democratic voters in South Carolina, released Saturday by McClatchy-MSNBC, found that 28% said they intended to vote for Clinton. Twenty-five percent said they preferred Obama and 18% backed Edwards.