campaign cash
You've heard the stories, eg an average senator has to spend 78% of his time soliciting campaign contributions and the like. They get owned pretty fast.
Your average person will also fall for any number of 'perks' offered them, which (especially) in DC is the fast track to compromises that can be blackmailed.
I can tell you from 1st hand sources that this is the case. I can't mention names, but one pol was "outed" when he wouldn't lay off a certain line of investigation involving the pinnacles of the military-industrial-congressional complex.
The media suddenly revealed all manner of embarrassments, all of which were situations instigated by a staffer whom party leadership INSISTED this person take on, one of the permanent power base that persists despite the outcome of elections.
Other words, they set the guy up, long before there was any need to have 'dirt' on the guy. They swiftly put a congress critter's bad behavior in the bank, to use if the idiot pol ever gets the idea they actually have any power and attempt to use it.
Sad but 100% the case. Probably less so at state and local levels. There I believe it's graft and corruption (sweetheart business deals with kickbacks) that compromises the average fallible human occupant of whatever office.
