ABC News Will Air Interview With Newt Gingrich's Ex-Wife Ahead of South Carolina Primary

ABC News will air an interview with Newt Gingrich's ex-wife Marianne Gingrich on Thursday night on Nightline, a spokesperson for the news division confirmed.

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The interview was conducted this week by Brian Ross, the network's chief investigative correspondent.

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Sources say the ex-Mrs. Gingrich is rather critical of her former husband, who faces a tough primary contest Saturday in South Carolina. That is hardly surprising. She has given numerous print interviews and in a 2010 Esquire feature she questioned the authenticity of Newt Gingrich's conversion to Catholicism.

The couple's 18-year marriage unraveled after Gingrich was revealed to be having an affair with a congressional aide 23 years his junior. He is now married to that erstwhile aide, the former Calista Bisek.

ABC News is likely to release excerpts from the interview early Thursday, well ahead of the evening's debate in South Carolina. And an executive at the network said that there is always a greater sensitivity toward airing critical interviews close to elections and that the Marianne Gingrich interview was carefully considered.

Gingrich's daughters from his first marriage, Kathy Lubbers and Jackie Cushman, defended their father in a letter to ABC News Wednesday:

The failure of a marriage is a terrible and emotional experience for everyone involved. Anyone who has had that experience understands it is a personal tragedy filled with regrets, and sometimes differing memories of events.

We will not say anything negative about our father’s ex-wife. He has said before, privately and publicly, that he regrets any pain he may have caused in the past to people he loves.

ABC News or other campaigns may want to talk about the past, just days before an important primary election. But Newt is going to talk to the people of South Carolina about the future -- about job creation, lower taxes, and about who can defeat Barack Obama by providing the sharpest contrast to his damaging, extreme liberalism. We are confident this is the conversation the people of South Carolina are interested in having.

 Our father is running for President because of his grandchildren -- so they can inherit the America he loves. To do that, President Obama must be defeated. And as the only candidate in the race, including Obama, who has actually helped balance the national budget, create jobs, reform welfare, and cut taxes and spending, Newt felt compelled to run -- to serve his country and safeguard his grandchildren's future.