The lesson here is that a society (which could be anything from a neighborhood to multiple nations), left on its own, will evolve into a Mafia-like organization, with leaders who combine corruption with concern for their underlings, warriors whose loyalty is based partly on oaths and partly on self-aggrandisement, and peasants who generally live in peace as long as they are compliant, but experience the sporadic violence around them.
It takes a concerted effort by a group of moral people to organize a republic designed to ensure that power does not coagulate into one place, nor that it has to be protected by force. We had it with the Founders. We may have it again, but it will take more than Trump to make it so.
Getting rid of the DC permanent population, implementing real term limits at the city and state levels, and ridding law of judicial ex cathedra would help end most of it.