You could be quite right - there is no true way to tell without looking over a long, accurate history of their behavior. However, this would be my "best guess" if I were placing a bet. Something in your head has to be a little bit differently wired to have an affair when you hold the most esteemed political position and the entire world is watching your every move (or trying to).

"Something in your head has to be a little bit differently wired to have an affair when you hold the most esteemed political position and the entire world is watching your every move (or trying to)."

Or maybe the reason some males seek an "esteemed political position" is so that they can have access to more sexual partners...