“Or maybe there truly are no good people in politics.”
I think many politicians get in to the game as good people. After that, it’s a matter of how long it takes for corruption to set in.
I believe the same thing. Look at local small town politics. You get a person for Sheriff that goes in a good person with all of the right ideas. If they are good when they go in, they are corrupt when they come out. All it takes is giving a favor to one important person or group and you are corrupted forever. It never goes away.