Chief investigative correspondent Brian Ross just sat down with Newt -- ex wife Marianne for a bombshell interview that airs tonight on Nightline and he's here now with an exclusive first look please... See More
Chief investigative correspondent Brian Ross just sat down with Newt -- ex wife Marianne for a bombshell interview that airs tonight on Nightline and he's here now with an exclusive first look please welcome Brian Ross -- Here it's gonna happen tonight very -- that she was -- -- -- eighteen years and -- in a bitter divorce -- past that she could end her ex husband career. With a single interview. Now -- tonight at -- -- -- tonight is the first television -- she's given since her divorce I don't really think this is much of the bombshell as some think it's going to be -- -- she spoke in measured tones but she does say because as a way. We talked to her that she does not think her ex husband has the moral characters and -- president. Given what happened to her and what he asked of her well we have a clip of that interview with her let's take a look. I said to him -- we've been married a long time. And he's said. Yes but you want me all to yourself. -- instead doesn't care what I do. Who was -- do you think it well he was asking to have an open marriage and I refused. He wanted an open marriage that I accept the fact that he he had somebody else and has life. And you said. Now. That is not a merry X. You know -- just -- just to show you women will go for anything. This guy how he attracts these women one after another is beyond me. Bryant now it. Did did he with his first why did he was infidelity with Mary -- the second life. She says they began their relationship while he was going through divorce -- it's now okay so this interview. How damaging will this be the new it's career -- his campaign haven't got the owners to decide and I think there are questions because -- -- campaigning. Talking a lot about family valley on news. And the sanctity of marriage between a man and a women that two women. I don't I think. He gutters -- -- -- it would enforce the defense of marriage act accident. -- exactly what you just -- He talks about the sanctity of marriage and what Marion Gingrich says I think it measured tones that still says -- That was not the way even it won't he had an affair for six years. At a time when he was criticizing President Clinton for his behavior my. And and you know what bothers her I think would bother lots of people she -- used to call her at night to praise -- -- is give the speech somewhere. And tell her how much he loved her and later admitted he was in bed next to coolest. Oh Nancy Davis. Is going to be more excited about -- going to be tonight President Obama or Mitt Romney -- yeah good question let me. Well -- -- these these are troubling questions that they are questions of character and character has been an important factor in this campaign. And it raised they've raised let me also say he's also according to add new he said I'm sorry I've done things in the past that -- Cause people pain and I'm sorry so doesn't that kind of pulling back of yes I did do these things -- he has admitted he's done things wrong and -- ask the forgiveness of god. Marianne says he's never asked for perfect if it's and I I. I'm about curry says we have no relationship although he said this morning -- and say anything negative about -- -- he's trying to take. High right now but what choice does he have to trash the ex wife that would really put -- helmet costs -- I love how he. -- -- He was he he asked Calista -- -- he asked her to marry him before he got a -- asked for divorce from his first wife goes -- his second. And many did the same thing with. -- -- acquiesced Calista to marry him before he even asked for divorce from -- he puts the cart before the court. -- that in the case of the first wife Jackie. -- she was going through cancer treatment when he asked for the boards and in the case of Mary and she had just been diagnosed with multiple sclerosis. And he Marron told don't putting stress on Maryland -- and I don't have. Add it later tonight I would marry and it seems like just from your own experience you should you know -- he did you know like to see people before you about of the marriage but sit -- should ABC be -- this interview. Before the primaries in South Carolina. -- I believe we should Eric tonight as we are going to a Nightline we can't we did night's debate I don't know I did the interview on Friday night. We want to give -- time to respond that we want to. Put it on we didn't want to put it on tomorrow day before the South Carolina primary so it's going to be on tonight Daniel I spent yesterday doing a lot of work on Mitt Romney. Looking into questions about his wealth in this offshore accounts there were we're looking at all the candidates in this coming elect I had I have to same premise is off the subject of -- and the Republicans and all that. But you are reading. Of the conversation between. The captain in Italy and -- diet either but I want to say it deserves -- a war. That was an extraordinary reading because we got a point of what was going outside just want to site -- put -- in my office next Friday. My my question. What has become an overnight Dick Callista and I agree to open marriage according to -- ends version of events -- residency doesn't -- everything right million -- Would you please -- remember this is an ex wife's will take a lot of things with a grain of salt -- but he has not spoken before and that this is her story. They're putting out that she's a bitter ex wife you know I read the Esquire article she doesn't sound better. What we overlook me tonight and what we'll be watching -- and Brian Ross you can -- his exclusive interview with Marianne Gingrich tonight on Nightline 1135 right here on May be.
This transcript has been automatically generated and may not be 100% accurate.