COLUMBIA, South Carolina : Hillary Clinton Friday called for calm as she slugged out the last rites of a race-tainted primary in South Carolina, where polls foresee a bounce-back win for her Democratic foe Barack Obama.

Saturday's first-in-the-South party nominating showdown is the last battle in a single contested state, before the tense White House race goes national with nearly two dozen contests on "Super Tuesday," February 5.

Obama is hungry for victory, after losing the previous two contests to the former first lady, but an unexpected defeat would likely deal a hammer blow to his hopes of taking her on, on the national stage.

Clinton backers beseeched voters not to pick Obama, simply because he is the first African-American with a realistic shot at the presidency, arguing Clinton's resume is superior.

"If all the black people in the world voted for the black people where would we go?" said local councilwoman Bernice Scott, as Clinton opened her day at a chapel of a largely black college here.

"If all the white people in the world voted for the white people? Where would we go?"

As Democrats eked out every last vote here, Republicans cranked up the pace of their sprint towards Tuesday's Florida primary, a make-or-break moment for the stuttering campaign of former front-runner Rudolph Giuliani.

The ex-mayor of New York used a high-stakes campaign debate Thursday however to dismiss speculation he may fold his campaign if he does badly in Florida, where Senator John McCain and ex-Massachusetts governor Mitt Romney, lead.

"I think we'll do very well in Florida and very well on February 5th," he said.

Back in South Carolina, Senator Clinton was flanked by two giants of New York's African American community, Congressman Charles Rangel and ex-mayor David Dinkins.

Like Clinton, Obama also planned an exhausting last-ditch swing across the state, opening his morning at a local deli, with a forum on healthcare.

Earlier, Clinton urged Democrats to calm down, after both sides accused the other of playing toxic racial politics.

"I think that there's been a lot that has been said on both sides and some of it has been, you know, kind of, generated and certainly stoked," Clinton said on CBS.

"That all needs to just calm down, and everybody needs to take a deep breath."

Obama's camp however has blamed Bill Clinton, mounting a vintage campaign swing for his wife, of fanning the flames, and all but accused the former president of lying about the record of his wife's rival.

An MSNBC/McClatchy poll Friday showed Obama leading his rival by 38 percent to 30 percent in South Carolina, based largely on staunch backing from African Americans.

But Obama's standing among whites in the southern state had plunged 10 percent in just one week, despite his efforts to portray himself not simply as an African-American candidate, but as someone with cross-racial appeal.

A Wall Street Journal/ NBC poll also had troubling signs for Obama, showing Clinton now leads the Democratic race nationally among white Americans 53 percent to 24 percent, compared to a 40-23 percent margin last month.

Obama meanwhile led Clinton, 63 percent to 23 percent among the minority African American community nationwide.

Dinkins meanwhile took a barbed shot at Obama, striking the Clinton campaign's theme that he is too inexperienced to be president.

"Lofty rhetoric is nice, but ultimately, you have to govern."

Obama stunned the former first lady with victory in the leadoff Iowa caucuses on January 3, leading to heady predictions from pundits that his grass roots movement would crush her White House dreams in a cross-country wave.

But Clinton pulled off a stunning comeback triumph in the New Hampshire primary five days later, and has since further dented her rival's hopes by capturing the Nevada caucuses.

As Republicans sparred in a campaign debate in Florida late Thursday, opposition to Clinton, who some analysts say is divisive, was the only thing uniting a fractured field.

Romney and McCain, who polls show neck-and-neck in the state, both lashed out at the former first lady's stance on Iraq.

Americans "don't want us to raise the white flag of surrender like Senator Clinton does," McCain said during the 90-minute debate in Boca Raton.

"They know they can win."

- AFP /ls