You can rely on humans to turn pretty much any form of political organisation into a hell of corruption, nepotism, status-seeking, short-term exploitation, and resource rationing.
You can also rely on humans to protect their own interests and stop criminals, but they must be allowed to do so. You have to have a system where the masses who are hurt by corruption have a chance to fight against it, if all power is held by the central party you will see the negative aspects of human nature while the positive aspects are suppressed.
