In a familiar scenario, wife stands by Edwards

Another politician strays outside his marriage and makes a public apology - and another wife stands by her man.

And once again, people wonder, "Why?"

This time it's former Sen. John Edwards, the once-presidential candidate, coming clean about his extramarital affair with a campaign videographer. His wife, Elizabeth, whose incurable cancer was diagnosed last year, concluded in her statement posted on the Web site Daily Kos:

"Admitting one's mistakes is a hard thing for anyone to do, and I am proud of the courage John showed by his honesty in the face of shame."

Political observer Julian Zelizer, a historian at Princeton University's Woodrow Wilson School, wasn't surprised.

"It seems to be the standard response," he said. He called Elizabeth Edwards' stance a variation on the "Hillary Clinton model."

"It's more about the political side than the personal side," Zelizer said of the Edwardses. "You deal with the personal on your own time."

We saw that scenario play out famously with Bill and Hillary, and more recently with Eliot and Silda Spitzer (formerly of the governor's mansion of New York) - proving infidelity knows no political boundaries.

And of course, who can forget the now infamous press conference where Dina Matos McGreevey froze her face in a smile as she stood by the side of her husband and he announced: "I am a gay American." (Of course, that initial support - and smile - melted away as the couple's nasty divorce and custody dispute played out in the headlines.)

Usually, it's in the wife's own best interest to grin and bear it. It gets rid of the media spotlight faster, Zelizer noted.

"There's a personal incentive not to carry this out in front of the cameras," he said.

While a woman who stays loyal may get flak, it's actually quite common. About 25 percent of men have affairs, and in many cases, women stick with their guys, therapists say. (Yes, we know women cheat too - about 15 percent - but that's another story.)

"People say, if X happens, I'll leave," said Sanjay Nath, a Center City psychologist and assistant professor of psychology at Widener University. "When that actually happens, people reevaluate. It's tough to make a black-and-white rule."

Often, women stay because they've invested a lot of time and energy into the relationship, and that relationship becomes part of their identity, he said. "These things are complicated."

Kimberly Flemke is a couples and sex therapist at the Council for Relationships, a Philadelphia counseling and research nonprofit. She cautioned about a rush to judgment - about either the cheater or the suffering spouse.

"It's so hard to generalize," she said. "Affairs don't happen in a vacuum. It involves two people. It's not because one person is such a jerk.

"We should feel sorry for them as a couple," she said. "I think they're both victims."