On CNN: John King to Anderson Cooper on why he asked Newt about "open marriage"

below, CNN transcript….

ANDERSON COOPER, CNN ANCHOR: I got to start with the start of this debate, John King. You asked the question which has been in all the headlines, has been all over statements made by Newt Gingrich’s ex-wife. Speaker Gingrich blasted you, blasted the media. Did ultimately actually answer the question, made some news with his answer. I want to play what he actually said.

(BEGIN VIDEO CLIP)

FORMER REP. NEWT GINGRICH (R-GA.), PRESIDENTIAL CANDIDATE: The story is false. Every personal friend I have who knew us in that period says the story was false. We offered several of them to ABC to prove it was false. They weren’t interested, because they would like to attack any Republican. They are attacking the governor, they’re attacking me. I’m sure they’ll presently get around to Senator Santorum and Congressman Paul.

(END VIDEO CLIP)

COOPER: Speaker Gingrich got a standing ovation in this auditorium for saying it was basically a completely inappropriate question.

JOHN KING, CNN CHIEF NATIONAL CORRESPONDENT: And he also scored points in the Monday night debate by attacking Juan Williams’s questions. I had a conversation with the speaker after.

Look, you’ve moderated these debates. This is one of those damned if you do, damned if you don’t. There’s a story that is making the rounds in the campaign. Is it an issue I’m happy came up in the last 48 hours before the South Carolina primary? Of course not. Is it an issue that voters in this state are talking about today? Is it an issue that he several times before the debate talked about in a very calm manner? He did.

COOPER: He talked about it today, earlier, in a much different manner. You knew — how much of this was debate theatrics on his part? Did you know he was going to have that response?

KING: I knew he was going to challenge the question. I don’t read minds, I don’t want to make a judgment about the speaker’s response. I have been covering politics for 25 years. I understood that if I asked the question, he was not going to be happy with it, and he was going to turn on me. Knew that coming in.

Again, you make a judgment call. Is it an issue in the debate? It might not be a great issue, it might not be an issue we’d like to talk about, but it is an issue in the debate. Some of the other candidates are talking about it, voters are talking about it in the state.

It was my judgment, my decision, and mine alone. If we’re going to deal with it, let’s deal with it up front, let’s not try to sneak it into the middle of the debate somewhere. And people at home either agree with that or disagree with that. You make the decision, you ask the question, and this is politics. This is politics. He’s trying to promote himself, promote his agenda. Of course he’s going to attack us. I don’t take that personally. We had a nice conversation afterwards. I’ve had a long relationship with the speaker. We don’t always get along, but I get how the business works.

COOPER: What do you — panelists, what do you all think?

DAVID GERGEN: Let me just talk about this. This is one of the most explosive moments that we have seen in debate history.

COOPER: In debate history?

GERGEN: Debate history. It was also one of the harshest attacks we’ve had on the press that I can remember in a long, long time. Very personal in the beginning.

And as a political matter, I think Gingrich saw a fastball coming, and for this audience, he smacked it right out of the park. I think there is a reasonable chance, after talking to the people here tonight, that he could win South Carolina based on that answer.

COOPER: I’ve heard a lot of people online saying that tonight, who’ve been live-blogging this.

GERGEN: But I want to say one other thing. As a journalistic matter, John had a duty to ask that question. It was the elephant in the room. After all, his wife is accusing him of hypocrisy, being a man of family values who had this private life that was in conflict with what he was preaching, and a man who went after Bill Clinton on these — on a similar set of issues. He would distinguish it because Clinton was a sitting president, but nonetheless, for a lot of voters, there is hypocrisy in that. So it was the elephant in the room.

And John King is known by most people here as one of the fairest people in the country. I think he did the right thing. I think he asked the right question. We had the explosion. And move on.