As of 1978, there were only 3 presidential candidates — known to Theodore White — who had not succumbed to sexual adventures with women who were not their wives.

"In his 1978 memoir, Theodore White, the most prolific and influential chronicler of presidential politics in the last half of the twentieth century, made John Kennedy and most of the other candidates he’d known sound like the Rolling Stones gathering up groupies on a North American tour. 'What was later written about Kennedy and women bothered White but little,' he wrote. 'He knew that Kennedy loved his wife — but that Kennedy, the politician, exuded that musk odor of power which acts as an aphrodisiac to of the other candidates he’d known sound like the Rolling Stones gathering up groupies on a North American tour. White was reasonably sure that only three presidential candidates he had ever met had denied themselves the pleasures invited by that aphrodisiac — Harry Truman, George Romney and Jimmy Carter. He was reasonably sure that all the others he had met had, at one time or another, on the campaign trail, accepted casual partners.” (Yes, White wrote his memoir in the reportorial third-person voice, and he used terms like 'musk odor.' It was a different time.)"

From the new book by Matt Bai, "All the Truth Is Out: The Week Politics Went Tabloid." That book is about how reporting on presidential candidates changed in 1987, when, for various reasons, the reporters who followed the candidates suddenly broke their conspiracy of silence and destroyed Gary Hart.