Republican presidential candidate Newt Gingrich, who once said "people have every right to ask the tough questions," launched an attack on CNN Thursday night after they gave him a chance to respond to allegations made by his ex-wife.

During the final debate before South Carolina's Republican primary, moderator John King asked the former House Speaker about if his second wife, Marianne, was telling the truth when she claimed he had asked for an "open marriage."

"I think the destructive, vicious nature of much of the news media makes it harder to govern this country, harder to attract decent people to run for public office, and I am appalled that you would begin a presidential debate on a topic like that," Gingrich said angrily.

"To take an ex-wife and make it a significant question in a presidential primary is as close to despicable as anything I can imagine," he added.

"This story did not come from our network," King replied. "It is the subject of conversation on the campaign."

"John, it was repeated by your network," Gingrich shot back, pointing a finger at the moderator. "Let me be quite clear: The story is false. Every personal friend I had who knew us during that period says the story is false. ... I am tired of the elite media protecting Barack Obama by attacking Republicans!"

But in an interview with NBC's David Gregory shortly after declaring he was a candidate, Gingrich welcomed questions about his personal life.

"I think that if people watch me, talk with me, get to know me, my hope is that a majority of Americans will decide that I can help this country get back on track in a way that no one else can," the candidate explained. "And if they decide that that's true, then I think we will have a very successful campaign. But people have every right to ask the tough questions and to measure somebody personally."

Watch this video from CNN, broadcast Jan. 19, 2012.