Not all Egyptologists would agree with my reconstruction here of the unification of Egypt and the birth of divine kingship as its governing logic, and few would consider the evidence to be as clear as I have made it out to be. But alternative reconstructions are, for the most part, less convincing. Merely to wallow in the ambiguities of the evidence leaves us in confusion, while an evolving, best-guess reconstruction provides at least a way to assimilate new evidence.
For the time being, the liberally interpreted, broad-brush generalizations of Hoffman, Kamil, and other Egypt specialists willing to go out on a limb seem to suggest that:
The population of Egypt was drawn into the Valley and Delta areas by climate change.
These populations took up farming, producing a settled, Neolithic adaptation (Badarian)
Small proto-states developed with a good deal of cultural sharing because of easy transit up and down the river. (Naqada I)
Elites in these communities arose, partly through the ability to participate in and control trade in "powerfacts" and other luxury goods from Egypt and beyond and to control and organize labor. As their populations expanded, the communities came into conflict with each other and gradually sought to conquer their neighbors. (Naqada II-III)
Local loyalties and inter-regional hostilities did not vanish with the unification of Egypt, and an important challenge for the central government was subordinating local interests to its own plans. (Early Dynastic)
Finally the logic of divine kinship was established, possibly as a deliberate strategy (a minority view), in order to force cooperation among still competitive regional forces. (Djoser & Imhotep)
Establishing and sustaining divine kingship —the ultimate totalitarian system— required the manipulation of religious symbols to give ordinary Egyptians a sense of the unlimited power and cosmic legitimacy of the state and its organs. [Note 22]
Stated this starkly, the case is extreme, but it is also similar to sequences of events we see in other parts of the world (such as in the Valley of Mexico), and illustrates a number of quite general tendencies in the development of archaic states.