(CNN) – Former House Speaker Newt Gingrich continued his push against rival GOP presidential candidate Mitt Romney on Monday, saying Democratic swipes against the former Massachusetts governor as a flip-flopper are "legitimate."
"If you run to the left of Teddy Kennedy, it is trickier than trying to run to the right of Newt Gingrich," Gingrich said in an exclusive interview with CNN's "John King, USA," referring to Romney's failed Senate bid against liberal lion Sen. Ted Kennedy of Massachusetts.
His comments come the same day the Democratic National Committee launched an aggressive, multi-state campaign against Romney, using a TV commercial that attempts to show the former governor changing his tune on a number of issues over the years.
Responding to critics who label Romney's record as inconsistent, Gingrich said: "Part of it is the way he (Romney) did some of it. I think it is legitimate."
Meanwhile, Gingrich admitted he was "wrong" when he indicated in a May interview that he favored some sort of mandate on health insurance.
Gingrich has since attempted to clarify those comments, saying he strongly opposes a federal health insurance mandate. But he denied his change in position amounted to the same "flip-flopping" label being lobbed against Romney.
Gingrich said Romney had failed to account for his health care positions, as the former governor strongly opposes President Barack Obama's sweeping health care reform, largely modeled after the Bay State system that Romney helped craft as governor.
"Mitt raised this issue in one of our debates. If I would have been clever, I would say I've admitted I was wrong," Gingrich told CNN Chief National Correspondent John King. "I've learned and I've changed my mind. Why haven't you?"
But in the same May interview, Gingrich said he wouldn't use the mandate issue against Romney, a tactic he now appears to be using.
Gingrich, who's surged in the polls in recent weeks, has repeatedly called on his fellow Republican opponents to resist attacking each other and take aim at Obama, instead.
But Monday night marked the second time Gingrich went after Romney, having told a South Carolina radio station earlier in the day that his record was stronger and more consistent than that of his closest competitor in the race for the White House.
"I wouldn't lie to the American people; I wouldn't switch my position for political reason. It's perfectly reasonable to change positions if you see new things you didn't see," he said in the radio interview.
"Everybody does that, Ronald Reagan did that. If you go around and adopt radically different positions based on need for any one election, people will ask, 'What will you tell me next time?'"