On the role of perpetual, blatant lying in creating totalitarian states, this was studied after WW2 by Hannah Arendt, particularly looking at the regimes of Hitler and Stalin.
www.openculture.com/2017/01/hannah-arendt-explains-how-propaganda-uses-lies-to-erode-all-truth-morality.html
the mechanism of propaganda in fostering “a curiously varying mixture of gullibility and cynicism with which each member… is expected to react to the changing lying statements of the leaders.” So she wrote in her 1951 Origins of Totalitarianism, going on to elaborate that this “mixture of gullibility and cynicism… is prevalent in all ranks of totalitarian movements”:
[Arendt says] "In an ever-changing, incomprehensible world the masses had reached the point where they would, at the same time, believe everything and nothing, think that everything was possible and nothing was true… The totalitarian mass leaders based their propaganda on the correct psychological assumption that, under such conditions, one could make people believe the most fantastic statements one day, and trust that if the next day they were given irrefutable proof of their falsehood, they would take refuge in cynicism; instead of deserting the leaders who had lied to them, they would protest that they had known all along that the statement was a lie and would admire the leaders for their superior tactical cleverness."
Arendt and others recognized, writes Levy, that “being made to repeat an obvious lie makes it clear that you’re powerless.” She also recognized the function of an avalanche of lies to render a populace powerless to resist, the phenomenon we now refer to as "gaslighting”:
[Arendt says] "The result of a consistent and total substitution of lies for factual truth is not that the lie will now be accepted as truth and truth be defamed as a lie, but that the sense by which we take our bearings in the real world—and the category of truth versus falsehood is among the mental means to this end—is being destroyed."
The epistemological ground thus pulled out from under them, most would depend on whatever the leader said, no matter its relation to truth.