For five days he puttered around press and police before admitting to vague "transgressions," invoking his family's privacy.
Not yet out of the woods, he follows a trail of powerful men who got caught with mistresses.
So does John Edwards, who fathered a child while his wife had terminal cancer. He perhaps used unfortunate wording in 2003, confessing he was "stripped bare" and had to work things out with his family.
Some are noted for their chutzpah: When New York Mayor Rudy Giuliani was caught with a girlfriend in 2001, he didn't apologize, but announced at a news conference he was divorcing his wife, journalist Donna Hanover.
So, too was New Jersey Gov. Jim McGreevey when he dropped the bombshell -- quivering wife at his side -- that he had an adulterous affair with Golan Cipel, a male former security aide
South Carolina's Gov. Mark Sanford was exposed in cheesy e-mails to his Argentinean mistress and "soul mate" ["I love your tan lines."]
But don't forget the contributions he has made to the American vernacular when he told his staff he would be out of contact: "I've been out hiking on the Appalachian Trail." (In fact, he had hiked on down to see his mistress.)
"Every single one of these men is a high testosterone guy -- most of these guys cannot even cross their legs they are so filled to the brim with testosterone," said E. Jean.
"If a woman marries a high testosterone guy, she can expect him to be a cad. You love him. He's brilliant, funny, great in the sack, attractive. But he will scoot around behind your back."
In an 2004 ABC poll among people who had ever been married or in a significant relationship, 14 percent said they'd cheated at some point. (10 percent of them were women and 17 percent men.)
Of the 20 letters a day E. Jean receives from women, about one-quarter say they suspect their husbands of cheating or are about to cheat.
"It's human nature to go for everything we can get," she told ABCNews.com. "If you want someone to be true to you, marry the dull, sweet, not very competent guy."
Prominent psychologist Frank Farley, an expert on risk-taking and sex from Temple University in Philadelphia, studies men like Tiger Woods who have what he calls "type T" personalities.
Along with Americans' demand for public heroes who are "not wimps," they get men who have affairs, he told ABCNews.com.
To understand public figures, first look at their jobs: "It's not 9 to 5 and restricted to one location, the rules of success are not clear, people can get voted out on a whim and no playbook is guaranteed," said Farley. "There is no tenure or job security -- it's an unpredictable career."
"Who's attracted to this?" he asks. "T types" -- risk takers who are creative, fearless, thrive on unpredictability and stimulation. "And what we found is they are sexual and sexy. They tend to like sex a lot."
"In everything from their eye contact to their body language, they are attractive to people," said Farley. "We've been analyzing a lot of data on Craigslist and we see a lot of women saying they want a 'man who can take charge.'"
Bill Clinton -- who survived impeachment in 1999 for sex with an intern -- is the "poster child" for the type T personality, he said.