The following is an excerpt from my short book Based Deleuze, which will be published on September 20th. Pre-order here and you’ll receive it by email as soon as it’s released.
Discussing the ideological valence of great thinkers is difficult because they have little use for the crutches of ideology. The difficulty is particularly acute today, when ideological labels are used so loosely, and often with ulterior motives. I should therefore clarify, at the outset, what I mean by "reactionary" in the subtitle of this book.
In some sense, Deleuze was explicitly anti-reactionary. He was anti-reactionary in the sense that he was anti-reactive, in the spirit of Spinoza and Nietzsche. To be a reactionary, in this pejorative sense, means to be always responding to active, superior forces, instead of becoming an active force; to be captured by sad affects, to be resentful, and to think and act with these as one's motive forces.
This common sense understanding of reactionism partially maps onto the modern political-ideological sense of the word. The data show that conservatives are more reactive to disgusting stimuli, for instance (Inbar et al. 2009). Experiments have shown that even just the presence of foul odors can make people slightly, but measurably, more conservative (Schnall et al 2008). Conservatives are more likely to see threats and reactively demand "law and order." Edmund Burke watched the French Revolution with horror, and famously wrote about his reactions. Henceforth, we'll refer to this aspect of reactionary or conservative politics as reactivism. I prefer reactivism to reactionism because it will remind us that left-wing progressive activism is much closer to this sense of "reactionary" than we are accustomed to thinking. Reactionary politics in this sense, reactivism, can be a failure mode of left-wing politics no less than right-wing politics.
Things get confusing because modern society also calls reactionary whatever transgresses left-wing or progressive norms. Nietzsche, for instance, is seen by many as a reactionary, even though one pillar of his whole life's philosophy is a contempt for reactive tendencies. Since World War II, any sufficiently disagreeable and strong-willed individual eager to avoid reactivism — who wishes to constitute an authentic, healthy, and autonomous existence — will generally be coded as reactionary. Even if their political beliefs are ideologically ambiguous or ambivalent. Strong and uncompromisingly active drives get coded as "reactionary" if the individual is not plausibly linked to the larger collective liberation struggle of some officially marginalized group. It is only in this sense of the term that we will find a "reactionary" component in the philosophy of Deleuze.
This latter sense of "reaction" is a recurring, subterranean tendency that can arise from the Left as well as the Right. It is most likely to emerge from the Right, but in periods when "the Left" becomes especially, excessively decadent - the responsibility to transgress "The Left" occasionally falls to an otherwise proper leftist.
This is how we will understand Deleuze's “reactionary leftism.”