The two leading Democratic candidates for the U.S. presidential race visited the state of Iowa Saturday with high-profile guests, in a head-to-head fight for votes from the state holding one of the nation's earliest nomination processes.

Senator Hillary Clinton brought her daughter Chelsea and her mother Dorothy Rodham to a rally in Des Moines for their first public appearances in support of Clinton's candidacy. Clinton's husband, former President Bill Clinton, is in South Carolina campaigning on her behalf.

Meanwhile, television host Oprah Winfrey began a weekend campaign tour with Senator Barack Obama through Iowa, New Hampshire, and South Carolina that is expected to draw thousands of potential voters.

It was Oprah's debut on the campaign trail in support of Obama.

A spokesman for the Clinton campaign said Clinton is a big fan of Winfrey, but expects voters to make their choices based on the strengths of the actual candidate.

Winfrey told the crowd at Saturday's rally in Des Moines that she does not know what kind of influence her appearances may have on Obama's campaign.

Some information for this story provided by AP.