John Edwards: Once a cheater, always a cheater?

A federal jury in North Carolina acquitted him on one count of violating campaign finance law Thursday and deadlocked on the five other counts against him. Prosecutors may still decide to retry him.

Politicians like Edwards and Newt Gingrich and celebrities like Ashton Kutcher and Jesse James seem to have no trouble attracting new girlfriends after public accusations of cheating.

It's always possible that people who have cheated in the past will not cheat in the future. But relationship experts say past behavior is a better predictor of the future than any cheater's promises.

"Denial can be really powerful in new relationships," said divorce recovery expert Andra Brosh, co-founder of Divorce Detox in Santa Monica, California. "People use it as a defense against knowing the truth. They don't look at all the facts, and ultimately, that ends up being a problem."

Cheaters are usually unsatisfied about something in their lives, experts say, or they wouldn't stray. But it's not always clear whether they're truly unhappy with their partners or about something they can't fix in themselves. Rarely does the cheater take responsibility for his (or her) life and getting out of it honorably. The spouses generally get the blame.

The reputation of Elizabeth Edwards, who separated from John Edwards in 2010 after 32 years of marriage and died of cancer in 2010, seemed to be on trial at times. A full participant in her husband's presidential campaign, she could be tough and blunt with campaign staffers. After reports surfaced of the affair, a witness testified, Elizabeth Edwards confronted her husband and ripped off her blouse to show her mastectomy scars. "You don't see me anymore," former staffer Christina Reynolds quoted her as saying.

"I've worked with countless people like this, and it's always the same," writes Mira Kirshenbaum, author of "I Love You But I Don't Trust You," a book about rebuilding trust in relationships, in an e-mail. "The cheater says, 'My spouse is fat/stupid/mean/boring/whatever (insert adjective) and I need someone who is skinny/smart/nice/interesting/opposite-of-whatever. You are skinny/smart/nice/interesting/opposite-of-whatever. So we can be happy forever.' "

The cheater's flattery can be intoxicating, convincing the other person that he or she is special and protected from being cheated on in the future. "They think they're special because they've been told they're special, and they want to believe it," Kirshenbaum said. "It's not that people don't think. It's that flattery and excitement short-circuit thought. "

And an ABCNews.com report that a juror might have been flirting with Edwards drew a lot of attention. Edwards flirting? Quelle surprise.

Of course, many cheaters can change if they have the desire. Much has been made of Callista Gingrich, who had an affair with Gingrich while he was married to his second wife, helping her husband convert to Catholicism. It's possible that Gingrich may stay faithful, if for no other reason than the 24-news cycle means public figures are being constantly scrutinized for evidence of bad behavior.

Affairs with married men or women are a high-risk gamble, says Lawrence Josephs, an Adelphi University psychology professor. Look at the evidence: Cheating is how he or she has chosen to solve relationship problems. "When you win such a man, you are winning someone who feels entitled to have his cake and eat it too and then lie about it," Josephs said.

So Callista Gingrich or any future Edwards girlfriend shouldn't assume she can change the cheater or that he will be different with her because she's so special. Their love, and his belief in God or occupancy of the White House, will not keep anyone faithful if he doesn't want to be or can't be faithful. (Former President Bill Clinton proved that point.)

It is possible for people in decent marriages to fall in love outside the marriage, but it's important to carefully assess whether the couple can get beyond the fantasy to the reality of love. "I would try to look carefully at the (cheater's) motivation and see what you feel is genuinely true between the two of us," said Susan Piver, author of "The Wisdom of a Broken Heart." "Do you admire their character otherwise? Do you feel loved and seen as you are?"

There needs to be some recognition that your relationship isn't a perfect replacement of an imperfect marriage.

"A question to ask yourself is, 'Does my relationship include difficulty?' " Piver recommended. "Are there things that bug me about this person? If there aren't, that would send up a red flag for me."

If they seem only motivated by ambition or simply looking for brighter horizons, "delete them from your Facebook account and move on," she says.