It's a self-perpetuating system involving interests, members of Congress, people in the executive branch and patronage positions and so on.
We build people up who have positions of power or visibility and venerate them and then have to show they have feet of clay.
Even those people in the leadership who've done commendable jobs may find themselves in the cross hairs just because it's possible there will be a more widespread desire for change.
You have smart people and a lot of money at stake. People are going to find loopholes.