Refusing to deal with realpolitik, is this a trope?

I was just wondering if there are stories where a person who comes into some form of power, or is expected to gain it and trained for it discover the sorts of moral compromises expected with that job.

So they refuse to take part and step away. Maybe they retire from society, maybe they wander the Earth doing small heroics.

Please use Trope Finder to search for and inquire about tropes, and YKTTW to propose new ones.