Rock Hill, S.C. ? Three Democratic presidential candidates criss-crossed South Carolina Friday, each courting voters outside their base and trying to rise above recent squabbles.

On the eve of today’s primary, Sens. Hillary Clinton and Barack Obama and former Sen. John Edwards campaigned around the state, as at least one poll showed the race tightening.

More than earlier contests, South Carolina has seen the Democrats throw sharp elbows. Clinton and Obama traded pointed exchanges at a debate Monday. Obama and Clinton’s husband, former President Bill Clinton, escalated the fight with jabs that some warned could create lasting divisions within the party.

On Friday, attacks were muted.

Sen. Clinton didn’t mention either opponent when she spoke to about 500 people in downtown Rock Hill. However, shortly before she arrived, her campaign held a conference call with reporters to discuss Obama’s “campaign attacks.”

Obama, speaking in Columbia, mentioned Clinton only in the context of her 2001 vote for a bankruptcy law that he said “made it much more difficult for people to get out from under crushing debts.”

Edwards tried to benefit from the tiff.

His campaign released a new TV ad that shows clips of Obama and Clinton bickering at Monday’s debate in Myrtle Beach and Edwards’ response. “This kind of squabbling,” he says, “how many children is this gonna get health care?”

“This New York-Chicago school of politics of personal attacks – South Carolina deserves better than that,” Edwards told several hundred people Friday in Columbia. “I’m for building people up.”

Edwards’ support inched up six points since the debate, according to a new C-SPAN/Zogby tracking poll. Obama had the support of 38 percent in the survey to Clinton’s 25 percent and Edwards’ 21 percent.

Much of Obama’s support comes from African Americans, who are expected to make up about half of today’s voters.

An MSNBC/McClatchy poll this week found that 59 percent of African Americans support the Illinois senator compared with 25 percent who back Clinton and 4 percent who favor Edwards.

Clinton made a clear pitch to African Americans Friday at Columbia’s historically black Benedict College.

She was joined on stage by former New York Mayor David Dinkins and Rep. Charles Rangel, D-N.Y., one of the highest-ranking black members of Congress. Stacey Jones, a college dean, said she understood the temptation to vote for Obama.

“For some of us it may take a very, very bold step to walk into that voting booth and focus on our community’s future rather than acting on pure emotion,” she said. “Let’s do the right thing and elect Sen. Hillary Clinton.”

Obama, who fared poorly with women in New Hampshire, gathered around a table with some in Charleston and Columbia to talk about economic issues that particularly affect women, such as child care costs and the demands of single parenting.