DES MOINES, Iowa – Oprah and Hillary – two women so famous that they are known only by their first name – were vying for the attention of Iowa voters Saturday on opposing sides of the intensely close presidential campaign.

While Hillary Rodham Clinton has become a familiar face here as she pursues the Democratic presidential nomination, Oprah Winfrey was making her debut on the presidential campaign trail in support of Clinton rival Barack Obama.

Winfrey planned to appear with the Illinois senator and his wife at two Iowa rallies expected to draw thousands – one in Des Moines and another in Cedar Rapids. Then she planned to travel with the couple Sunday to two other key primary election states – New Hampshire and South Carolina.

Meanwhile, Clinton brought along two women for their debut on her campaign – daughter, Chelsea, and mother, Dorothy Rodham. Neither had appeared publicly yet with the senator in her presidential bid.

“Senator Clinton is a big fan of Oprah’s, and she thinks it is great for candidates to have surrogates campaign on their behalf,” said Clinton spokesman Jay Carson. “Though on January 3, Iowans are going to come out to caucus and make their decisions based on the actual candidates record of fighting for and delivering change.”

The Democratic race in Iowa is tight, with Obama, Clinton and 2004 vice presidential nominee John Edwards in a dead heat.

The Obama campaign said Winfrey was already a boon to the campaign even before her appearance.

Local news has featured stories every day this week about her visit. Thousands of voters, many who’ve never had contact with the campaign before, have signed up on his Web site or come into campaign offices to pick up tickets. Those who agreed to volunteer at least four hours during the past two weeks got priority tickets, and the campaign says 1,385 people took them up on the offer.

When Iowans come to hear Oprah, they also will get a pitch from the senator. And they will be approached by campaign volunteers armed with literature and requests to commit to Obama – 135 will be working the Des Moines site alone.

The Obama campaign is particularly interested in winning over women, who have been leaning toward Clinton in the polls.

Winfrey gave Obama’s White House bid a boost months before her decision to join him at campaign appearances. In September, she hosted a gala fundraiser attended by high-wattage stars at her palatial estate in Montecito, Calif., raising $3 million.

But Winfrey wasn’t the only superstar on the campaign trail Saturday. Former President Clinton was campaigning for his wife in Charleston, S.C., a day before the talk show host and media mogul was to join Obama for an event at the University of South Carolina’s football stadium.

Hillary Clinton pledged “change across the generations” as she courted voters with her 88-year-old mother and 27-year-old daughter. “We’re getting close to the caucuses,” the senator said. “I always think it’s better to go to the caucuses with a buddy. Today, I’ve got some buddies with me.”

The three had breakfast at a popular Des Moines delicatessen. Chelsea Clinton worked the crowd, taking aside Darlene Dols of Chaska, Minn., who declared herself undecided in the race, though her sister backs Clinton.

“Is there anything I can tell you that would put you over the edge for my mom?” Chelsea asked. “Listen to your sister.”