DILLON, S.C. (AP) He's not on the ballot but Bill Clinton seemed to dominate the South Carolina presidential campaign, disparaging Barack Obama and journalists and predicting that many voters will be guided mainly by gender and race loyalties.

The former president suggested that his wife, New York Sen. Hillary Rodham Clinton, may lose Saturday's Democratic primary because many black voters will side with Obama. The unusually direct comment on the possible role of race in the election was in keeping with the Clintons' bid to portray Obama as the clear favorite, thereby lessening the potential fallout if it proves true.

Voting for president along racial and gender lines "is understandable, because people are proud when someone who they identify with emerges for the first time," the former president told a Charleston audience Wednesday while campaigning for his wife, a role he has played all week.

His comments and a later outburst with a reporter came on a day when Obama continued to challenge Hillary Clinton's candor and trustworthiness. He said his chief rival has indulged in double-talk on bankruptcy laws, trade and other issues.

The atmosphere grew more charged after Clinton's campaign aired a radio ad in South Carolina suggesting Obama approved of Republican ideas. Obama responded with his own radio spot that says, "Hillary Clinton will say anything to get elected."

Politicians "don't always say what they mean, or mean what they say," the Illinois senator told about 900 people at Winthrop University, in Rock Hill, Wednesday. "That is what this debate in this party is all about."

At each of three main stops Wednesday, Obama mocked Clinton for saying she voted for a 2001 bankruptcy bill but was happy it did not become law.

"Senator Clinton said, 'Well, I voted for it, but I hoped the bill would die,'" he said, drawing hoots from the university crowd.

Bill Clinton, campaigning on the coast while Obama was inland, said Obama and the media had stirred up tensions over race in response to some Democrats' criticisms of the couple's strategies.

"I never heard a word of public complaint when Mr. Obama said Hillary was not truthful," and had "no character, was poll-driven. He had more pollsters than she did," the ex-president said in a heated exchange with a CNN reporter. "When he put out a hit job on me at the same time he called her the senator from Punjab, I never said a word."

It was not clear what he meant by "hit job."

The former president has accused Obama of exaggerating his anti-war record and handing out undeserved praise to Republicans. Clinton said he personally witnessed Obama's union forces intimidating Nevada caucus-goers and said an Obama radio ad suggested how Democrats could keep votes from his wife.

Last year, Obama's campaign circulated a memo describing Hillary Clinton as "D-Punjab," a reference to her Indian-American donors. Obama has said that was a mistake.

Bill Clinton said civil rights leaders Andrew Young and John Lewis have defended his wife. "They both said that Hillary was right and the people who attacked her were wrong and that she did not play the race card, but they did," he said.

Clinton said the news media is much tougher on his wife than on Obama. At the end of the exchange, he told the CNN reporter, "Shame on you."

Clinton also told about 100 people in Charleston that he was proud of the Democratic Party for having a woman and a black candidate and he understands why Obama is drawing support among blacks, who may comprise up to half of Saturday's turnout.

"As far as I can tell, neither Senator Obama nor Hillary have lost votes because of their race or gender," he said. "They are getting votes, to be sure, because of their race or gender that's why people tell me Hillary doesn't have a chance of winning here."

Associated Press writers Mike Baker in Charleston, S.C., and Jim Kuhnhenn in Washington contributed to this report.