If it had been shown that he had a gay lover on the side, he would have been held up as a hypocrite and likely have lost his next election. What he was exposed doing though was not only hypocritical and creepy but illegal.
I would say that it’s the illegal part that makes a difference, but there are too many politicians who are caught doing things illegal that do not lose their jobs for me to think that’s all there is too it.
Recently, a congressman was charged with assault (I think) for pushing an airline employee that told him he had to leave a restricted area. Assault, abuse of power (“You can’t make me…I’m a congressman!”), and just plain bad manners do not have the power to capture attention like anything having to do with sex.
So, minor illegalities and sex scandals can be tolerated until the voters get another cut at you. Put “sex” and “illegal” together and you’re a gonner**…if for no other reason than your own party will want to get your embarrassing butt out of the way as soon as possible.
** Excepting of course where the definition of “is” is in dispute.