CHARLESTON, S.C. – Presidential candidate Newt Gingrich said Saturday that Republicans will err if they don’t scrutinize Mitt Romney’s role in private equity firm Bain Capital.

Gingrich spoke on a Fox News program that included five of the six Republican candidates. Each fielded South Carolina voters’ questions for almost 20 minutes. Rep. Ron Paul of Texas did not participate.

Romney said he wants the federal government “out of the housing business” so the free market can work.

Jon Huntsman was asked why he supports legalized abortion in cases of rape and incest. “I am pro-life,” Huntsman said. “I have stipulations.”

Rick Santorum noted that he does not support legalized abortions in cases of rape or incest. But he supports the death penalty, he said, because it does not involve “innocent life.”

Texas Gov. Rick Perry touted his call for a 20 percent flat tax. He said he would keep the deductibility of charitable gifts, local taxes and mortgage interest payments.

Associated Press