There is a key passage in Eric Hoffer's The True Believer that helpfully elaborates on David Denby's questions and answers about Ted Cruz's "nihilistic charade":
Hitler, who had a clear vision of the whole course of a movement even while he was nursing his infant National Socialism, warned that a movement retains its vigor only so long as it can offer nothing in the present.
Nothing, that is, but anger, disaffection, fierce antipathy to the present order. Only through the exaltation of the fanatical leader can a splendid new age of creativity and innovation--a rebirth--come about; until then, nothing but hatred must be poured on the ancien régime.
In other words, Cruz is only doing his thing by the book.