The five remaining candidates, including Romney, held a debate on January 16 in South Carolina.
Reports say that Romney, who already has victories in New Hampshire and Iowa, could move close to becoming the almost certain Republican nominee if he wins the January 21 primary in South Carolina.
Texas Governor Rick Perry, who is lagging near the bottom of polls, called on Romney to release his tax information to shed light on how he became so wealthy. Romney has faced allegations that his firm cut jobs and plundered companies that it took over.
"Mitt, we need for you to release your income tax so the people of this country can see how you made your money," Perry said.
Romney responded that he was considering releasing his tax records.
"My record is out there, [I'm] proud of it, and I think that if people want to have somebody who understands how the economy works, having worked in the real economy, then I'm the guy that can best post up against Barack Obama," Romney said
The debate occurred just hours after the former U.S. ambassador to China, Jon Huntsman, withdrew from the nomination contest and formally gave his endorsement to Romney, the former Massachusetts governor.
In addition to Romney and Perry, the other remaining candidates include former House Of Representatives Speaker Newt Gingrich, former Pennsylvania Senator Rick Santorum, and Texas Congressman Ron Paul.
compiled from agency reports