Moretti, Franco. "'A Huge Eclipse': Tragic Form and the Deconsecration of Sovereignty."
Genre 15 (1982). 7-40.

Thesis: Here is Moretti's statement of his general purpose:

In the pages that follow . . . I shall attempt to indicate the elements essential to a definition of tragic form, and to demonstrate that the historical "task" effectively accomplished by this form was precisely the destruction of the fundamental paradigm of the dominant culture. Tragedy disentitled the absolute monarch to all ethical and rational legitimation. Having deconsecrated the king, it thus made it possible to decapitate him.  (7-8)

My understanding of this is that the stories which tragedy—especially Shakespearean tragedy—tell about kings, stories in which the king willfully and unreasonably plunges his country into chaos, shows no evidence of God's plan in action, and that kingship is therefore "deconsecrated."

About Macbeth, Moretti writes,

Macbeth's dilemma is that coexisting in him are both the imperative of power and the imperative of culture, will and reason together. He cannot yet unburden the exercise of power—power as such—from the need for its cultural legitimation. Precisely this co-presence of irreconcilable drives deprives his life of a unified meaning: "It is a tale / Told by an idiot, full of sound and fury, / Signifying nothing" (V. v. 26-28). That is to say: only a madman or imbecile (in effect, those like Edgar or Malcolm who step in claiming to "conclude" the tragedy) can think that Macbeth's story can be "told," ordered on the basis of comprehensible meanings. Such a combination of narrative and value-judgment has become impossible, and what remains is only "sound," the word without force, and "fury," force without sense. Which is, in miniature, the very lesson of tragic structure as a whole.  (27-28)

Evaluation: Moretti's argument is complex and subtle, and I didn't have the patience to follow it all, or even to read the whole essay, but I think his general idea applies better to Hamlet than it does to Macbeth. In Hamlet the usurper Claudius is replaced by Fortinbras, who just happens to be in the neighborhood, but in Macbeth it is Malcolm who comes to the throne at the end, and Malcolm is the designated heir of the godly Duncan and is supported by the English forces of the godly Edward the Confesser.

Also, I have no idea why Moretti refers to Malcolm as an "imbecile."

Bottom Line: Beyond me.