One of the leading ideas about the origin of the state is the "hydraulic theory". In a nutshell and doing it no service, the theory states that societies dependent on irrigation for agriculture were vulnerable to someone's taking control of the water and exerting power over others. Some warlord and his goons could seize the waterworks or provide protection of the waterworks from other warlords and their goons in exchange for taxes and obedience. I suppose any necessary infrastructure would do as a basis for enslavement.
It seems to me that sedentism is the first requirement. It would be hard, although not impossible, to lord it over foragers. I suppose you could stake out a claim to a hunting ground and demand tribute, but the effort involved in that would exceed the effort involved in being a collaborative forager or the leader of a foraging band. Nomads would be easier to extort from since they need grazing lands and water that you could, in principle, control. This would probably not be very profitable as the sole basis of a protection racket but it might be a good sideline for an already established protostate. Agriculture with its concomitant supluses and the greater division of labor is a prerequisite to a truly profitable racket.
It's possible that some of the early racketeeers may have actually added value by protecting their victims, er subjects, from the ravages of worse racketeers and by extracting less than they might have. Some early racketeers may have hit upon the idea that there was an optimum level of extraction that would generate the most revenue while encouraging industry and the convenient acquiesence of the subjects in the rule of the racketeers. Eventually, some of the racketeers would have discovered the idea of the republic wherein the racketeers would rule under the fiction that they did so with the affirmative consent of the ruled.
The lesson of history, I suppose, is that there is always some asshole who is ready to to serve as your warlord. If you have anyting you care about, that's the source of their power. Freedom, it has bee famously said, is just another word for nothing left to lose.