Posted Jan 16, 2012 9:31pm EST

MYRTLE BEACH, South Carolina—Rick Santorum put a target on Mitt Romney’s back in tonight’s Fox News presidential debate here, and didn’t let up.

Asked whether candidates should refrain from running negative attack ads, Santorum opened fire on Romney, unloaded on the former Massachusetts governor,  over an ad run by his Super PAC that suggested that Santorum supported allowing jailed felons to vote.

Santorum said he supported allowing rehabilitated convicts the right to vote, calling it a civil rights issue, especially in the African American community — and he invoked the memory of Rev. Martin Luther King, Jr. to that effect.
He then asked Romney what his position was on the issue — in a clearly pre-planned line of attack. When Romney tried to evade by saying he can’t control what his Super PAC does, Santorum cut him off, pressing him to answer the original question.

“This is actually my time. Answer the question,” Santorum said, interrogating Romney.

Romney finally relented, saying “I don’t think people who committed violent crimes should be allowed to vote again.”

But Santorum had another attack up his sleeve, noting that while Romney was governor in Massachusetts his state’s policies were more liberal — he also asserted that Romney never tried to change the law to keep violent offenders from voting again, even before their sentences were completed.