http://abcnews.go.com/Health/story?id=5559242&page=1 John McCain. Then Newt Gingrich. And now John Edwards. ... Edwards' betrayal of his wife at her most vulnerable moment -- as a cancer patient -- is more common than conventional wisdom suggests, according to infidelity experts. A mistress of former House Speaker Gingrich told Vanity Fair they had their tryst as his first wife recovered from uterine cancer surgery in the 1980s. While McCain was married to his first wife, who was disabled from a car accident, he was "aggressively courting a 25-year-old woman who was as beautiful as she was rich," according to a New York Times colunmist's account of the 1970s incident that predated McCain's election to the Senate. Both McCain and Gingrich have admitted to the affairs.