From a section in Counterpath written by Catherine Malabou (in working towards a blog post to-come on this strange, beautiful, and rather helpful book):
The Deconstruction Jetty and Its Resistance to Theory
The text "Some Statements and Truisms..." again takes up this set of reasons. The word "theory," Derrida says, is "a purely North American artifact," which refers to disciplines taught in certain American university departments of "literature." He groups together a set of "-isms": "New Criticism, structuralism, poststructuralism, postmodernism, post-Marxism, new historicism, and so on," as well as "deconstruction" and "deconstructionism." From that point of view, the general title of the colloquium he is addressing, "The States of 'Theory,'" can have real meaning only in the United States. What is at stake here is not, as one might understand from a European perspective, scientific (physics or mathematics), epistemolical, or even philosophical theory. "Theory" corresponds to "the opening of a space, the emergence of an element in which a certain number of phenomena usually associated with literature will call for trans-, inter-, and above all ultra-disciplinary approaches" such as linguistics, psychoanalysis, feminist studies, structuralism, or deconstruction.
These disciplinary fields act as forces. In order to characterize them, Derrida convokes the figure of the "jetty," a word that should be understood in two senses: in the first place, the jetty designates a movement (one can hear in it the French verb jeter, "to throw"). Derrida calls this "first" jetty a "destabilizing" one:
By the word "jetty" I will refer from now on to the force of the movement--which is not yet sub-ject, pro-ject, or ob-ject, not even rejection...that finds its possibility in the jetty, whether such a production or determination be related to the subject, the object, the project, or the rejection. 
Each theoretical jetty has an antagonistic relation to the other. Whereas it could not simply be part of a whole, it nevertheless projects itself as a whole. It cannot comprise itself without attempting to include and englobe all the other parts, without trying to account for them. For example, what, in the field of "literary theory" in the United States is these days called "Marxism" appropriates to itself fundamental concepts borrowed from psychoanalysis, from structuralism, and from poststructuralism. By means of this operation the jetty at the same time stabilizes what it names and transforms it into a "state":
Each theoretical jetty is the institution of a new statement about the whole state and of a new establishment aiming at state hegemony. Each jetty has a hegemonic aim, which isn't meant to subjugate or control the other jetties from the outside, but which is meant to incorporate them in order to be incorporated into them. 
The second sense of the word "jetty" then comes into view, that of the "stabilizing jetty," which, like the construction in a harbor that is designed to protect ships anchored at low tide, fixes a set of axioms. In the order of theory, the stabilizing jetty
proceeds by predicative clauses, reassures with assertory statements, with assertions, with statements such as "this is that": for example, deconstruction is this or that.
For instance, one assertion, one statement, a true one, would be, and I would subscribe to it: Deconstruction is neither a theory nor a philosophy. It is neither a school nor a method. It is not even a discourse, nor an act, nor a practice. It is what happens, what is happening today in what they call society, politics, diplomacy, economics, historical reality, and so on and so forth. Deconstruction is the case. I say this not only because I think it is true and because I could demonstrate it if we had time, but also to give an example of a statement in the static form of the jetty. 
Since it is clearly possible to formulate assertions on the subject of deconstruction, it remains subject, like every other theory, to the law of the stabilizing jetty. In other words, it is capable of being transformed into "deconstructionism," the formalization and systematization of technical rules, of teachable methodological procedures, into the codification of a discourse, etc.
There is deconstructionism in general each time that the stabilizing jetty closes and stabilizes itself in a teachable set of theorems, each time that there is self-presentation of a, or more problematically, of the theory. 
Yet, to the very extent that the statements or assertions that deconstruction gives rise to fundamentally oppose or resist "theory," it remains a destabilizing jetty even within its rationalizing and controlling structure. Because it destabilizes the conditions of possibility of objectivity, of the relation to the object, of everything that constitutes an assured subjectivity in the form of the cogito, the certainty of self-consciousness, etc., deconstruction proves the impossibility of closure, of totality, of a system or discourse of or on method. Deconstruction is not a theory of theory. And California, the seismic state of theory, is not its only homeland. (Malibou, Counterpath, 224-226)
 Derrida. "Some Statements and Truisms," in The States of Theory, 65
 Ibid., 68.
 Ibid., 84, 85.
 Ibid., 88.
Malibou then turns to a brief discussion of "The Time Is Out of Joint," in Deconstruction is/in America, thus concluding an entire chapter entitled with the question, "Deconstruction is America?"
So it is a question again, for Derrida, of two potential forces -- "stabilizing()destabilizing" that cannot be reduced one to the other, but at the same time never cease to condition each other. Of course as easy as it may be to state, such is in fact extremely difficult to think. One may well grasp that 'deconstructionism' may be subjected to theory, or to theorizing, but that this occurs simultaneously along with the action of the "destabilizing" force (of the very conditions of possibility!) is harder to swallow. Derrida insists on giving these two forces equal weight. But at the same time neither of them may add up to their potential, which remains hidden, or in a sense secret. That is, Derrida's purpose is not simply to demolish a pseudo-concept vulgarly employed as "Theory" in America. Rather 'theory' in America, in some unique but unclassifiable, un-localizable sense (unattached to any nationalism, religious dogma, or Schmittian state) needs to be defended. A space needs to kept clear and thoughtfully preserved--cared for--so that it may come into being. As 'democracy,' perhaps.
The concept of 'autoimmunity' that Derrida appears to formulate rather late in his career may in fact be seen to run through his work, and in particular as it relates to his reading of the site, or rather nonsite/place-name, 'khora' (transformed from the Timaeus). I will try to draw on the passage in Counterpath entitled, "The Khora--Nuclear Catastrophe" in a future post.
nb. Some more thoughts on 'theory' are helpfully compiled here: Theory's Empire: Dissenting With Dissent