Can an old story be a bombshell?

It’s a very busy day in the race for the Republican nomination. The results of the Iowa caucuses point towards a new winner; Rick Perry is out; Mitt Romney has a variety of problems (tax rates, tax returns, stashing cash in the Caymans); and there’s a debate tonight.

But one of the controversies getting plenty of media oxygen today is this story from ABC’s Brian Ross, which will air tonight on “Nightline” (soon after the debate on CNN).

In her first television interview since the 1999 divorce, to be broadcast tonight on Nightline, Marianne Gingrich, a self-described conservative Republican, said she is coming forward now so voters can know what she knows about Gingrich.

In her most provocative comments, the ex-Mrs. Gingrich said Newt sought an “open marriage” arrangement so he could have a mistress and a wife.

She said when Gingrich admitted to a six-year affair with a Congressional aide, he asked her if she would share him with the other woman, Callista, who is now married to Gingrich.

“And I just stared at him and he said, ‘Callista doesn’t care what I do,'” Marianne Gingrich told ABC News. “He wanted an open marriage and I refused.”

To be sure, this isn’t what Gingrich needs right now. And given his background of attacking Democrats for “breaking down traditional marriage,” the disgraced former House Speaker’s scandalous personal life raises questions about his odious character.

But I’m not quite clear why this is considered new. Marianne Gingrich did an interview with Esquire nearly two years ago in which she told the magazine the same thing — the powerful Republican lawmaker “asked her to just tolerate the affair,” she said at the time. The interview was widely noticed, and I remember writing about it.

Perhaps there’s some new details Marianne Gingrich shared with ABC, but the scoop the network is pushing is the allegations that the GOP leader wanted an “open marriage.” As best as I can tell, we’ve heard this allegation before. Even some of the wording in the reports is the same.

Can an old story be a bombshell? Or is this just a situation in which the political world forgot what it learned two years ago, and this just seems new?