Ron Davies, when Clinton made his (in)famous "I did not have sexual relations with that woman ... " spiel, Paula Jones's lawyers were trying to use any and every bit of evidence of "sexual impropriety" against him in her lawsuit.   Consensual sex with an adult should not have been relevant, but since Monica was a White House intern, they probably would have spun the affair with her as an example of sexual harrassment.   I think that's a stretch, but I can see how, with the Jones case still unresolved, Clinton would deny having had "sexual relations" (specifically and weirdly defined by the Jones case judge) with Lewinsky -- no doubt assuming there'd be no way to disprove his statement about what had occurred in private.   And had it not been for good ol' Linda Tripp, how would anyone have known?

Heck, who knows HOW many of our fearless leaders have committed indiscretions that we'll never know about because they happened behind closed doors?