(CNN) -- Hillary Clinton has returned to South Carolina to make her final push before the state's Saturday primary.
Sen. Hillary Clinton spent most of the week campaigning outside South Carolina.
The New York senator spent the last two days looking ahead to the "Super Tuesday" states while her husband made the rounds in South Carolina.
Her absence led some to question whether she was conceding the state to rival Barack Obama, but she's stepping up her campaigning in the final hours.
Clinton on Thursday was delivering a speech on the economy in Greenville before heading to Anderson. Obama was attending an event in Kingstree, a roundtable discussion in Beaufort and rallies in Beaufort and North Charleston. Clinton and Obama were to appear separately on African-American radio host Michael Baisden's nationally syndicated show.
Clinton and Obama are leading the race in South Carolina, ahead of former North Carolina Sen. John Edwards, who was holding events in Greenwood and Seneca Thursday.
The Saturday primary wraps up a week marked by tense rhetoric regarding the role of race in the presidential election.
The candidates have been trying to win the support of South Carolina's African-American voters, who make up roughly 50 percent of the state's Democratic primary electorate. Obama is leading that group in most recent surveys.
Obama's wife, Michelle, was brought into the race conversation Wednesday when she was asked what role it played in the election.
"Race is still an important issue in this country. ... The issue is real, but our belief is that the decision of who will be the next president will not be based solely on race or gender," she told a News 14 Carolina reporter.
"My deep hope is that people will base their decision on who they think they can trust, who's got a vision for the country, who's bringing a different tone to politics, who's going to really take this country in a different direction. And quite frankly, I think the only person who comes close to that is Barack, and he happens to be a black man," she said.
Bill Clinton Wednesday said race and gender considerations hadn't cost his wife or Obama any votes so far -- but that some female voters might be drawn to Clinton because of her gender, and some black voters to Obama because of his race. Watch a fired-up Clinton campaign for his wife »
"They are getting votes because of race and gender. That's why people tell me Hillary doesn't have a chance to win here," he said.
Clinton's campaigner-in-chief drew criticism this week for his attacks on Obama.
A prominent Obama supporter Wednesday compared the ex-president's appeals for his wife to the tactics used by Lee Atwater, a hard-hitting Republican strategist who worked for Presidents Ronald Reagan and George H.W. Bush and whose tactics were reviled by many Democrats.
In an interview with CNN, Dick Harpootlian, a former chairman of the South Carolina Democratic Party and an Obama backer, said some of Clinton's recent remarks on the campaign trail were appeals based on race and gender, meant to "suppress the vote, demoralize voters and distort the record."
When CNN's Jessica Yellin asked Clinton about Harpootlian's comments, Clinton disputed the charge and lashed out, saying: "You live for this. This hurts the people of South Carolina." Watch Clinton get upset with a CNN reporter
Obama Thursday said Bill Clinton was "entirely justified" in campaigning for his wife, but accused him of skewing his record.
"He can be as vigorous an advocate on behalf of her as he would like. The only thing I've been concerned about is when he makes misstatements about my record," the Illinois senator said.
Michelle Obama also stepped up for her husband in a mailer Thursday, saying while they expected Bill Clinton to have a visible presence in the campaign, "What we didn't expect, at least not from our fellow Democrats, are the win-at-all-costs tactics we've seen recently. We didn't expect misleading accusations that willfully distort Barack's record."
"Barack Obama isn't relying on a former president of the United States to campaign for him. He's relying on us -- you, me, and hundreds of thousands of people like us who are giving whatever they can afford to support this movement," she said in asking for donations to the campaign.
The back-and-forth between the Obama and Clinton camps transferred to the radio, as both candidates launched attack ads.
Clinton's spot highlights a portion of Obama's recent interview with the Reno Journal-Gazette in which the Illinois senator said in part, "The Republicans were the party of ideas for a pretty long chunk of time there over the last 10, 15 years."
"Really? Aren't those the ideas that got us into the economic mess we're in today?" a narrator asks.
The Clinton camp pulled the ad less than 24 hours after it was launched. Clinton's South Carolina spokesman did not provide a reason why the ad was pulled, saying only, "we are on schedule with our closer ads starting."
Obama's radio ad includes the claim Clinton is the bearer of "false attacks" and "will say anything to get elected."
"Obama did not say that he liked the ideas of Republicans," the announcer continues.
"But it was Hillary Clinton, in an interview with Tom Brokaw, who quote 'paid tribute' to Ronald Reagan's economic and foreign policy."
"She championed NAFTA -- even though it has cost South Carolina thousands of jobs. And worst of all, it was Hillary Clinton who voted for George Bush's war in Iraq."
The ad closes with the announcer saying, "She'll say anything and change nothing. It's time to turn the page." E-mail to a friend
CNN's Jessica Yellin, Chris Welch, Emily Sherman and Rebecca Sinderbrand contributed to this report.