I admit "inverted totalitarianism" is a bit awkward. But I think it's pretty clear that it means a variety of totalitarianism, which by definition excludes democracy.
As for "successful totalitarianism": I think that at some point Wolin suggests that in the same way that despotism is the corrupted form of monarchy, classical totalitarianism (e.g. Nazism) was the "corrupted" form of inverted totalitarianism. A bomb, H bomb, Minuteman / The names get more attractive / The decisions are made by NATO / The press call it British opinion -- The Three Johns