I have become somewhat confused by Voegelin's use of the word "reality." What precisely does he mean by it? Are partisans of Second Realities like the denizens of Plato's Cave? And if so, isn't Voegelin simply restating Plato's metaphor in a less poetic fashion?
No, I don't think so, Dumb_Ox. The denizens of Plato's cave are clueless -- until they "turn around" and see that the Light is the Source of the "shapes" they have seen projected on the walls of their cave. (A major reorientation of the person is ordinarily implied by such a process.)
The images projected on the cave wall are only "fictions" of the Real, not even images of the real, but mere shadows of Reality. What Voegelin is suggesting is that certain denizens of the cave will take the "perigoge" -- they'll "turn around" to face the Light. But they will detest what they then see -- precisely because they have come to prefer the "shadows of Reality" to Reality itself -- and so rebel against the Light with every fiber of their being.
Voegelin is describing here, not "explaining." (How does one explain a thing like this, assuming only rational people are involved?)