bad reading comprehension

I wrote the following comment on Instapundit regarding a post about science as a priesthood:

Postmodernist ninny Michel Foucault, who saw everything in terms of power relationships, viewed science as a priesthood decades ago—the white lab coats, the holding and keeping of specialized knowledge, the long initiation needed to access such knowledge, and the power that was associated with it. To be clear, I'm not a Foucaultian, and I think most of those PoMo Frenchies (like Foucault, Jacques Derrida, and Jean Baudrillard—a favorite of Russell Brand) basically had their heads up their asses. But my point is that the science-as-priesthood image has been around a long time.

I got the following reply, which seems to have missed my point:

Derrida doesn't see power relationships. He's more into what more you know about words that you didn't think you knew.

I can tell this guy has almost no knowledge of Derrida, but more important, he seems to think I'd associated Derrida with power relationships. Why would he do that? Anyway, I wrote a civil reply (and here's hoping that that's the end of the matter):

With Derrida, you get concepts like "différance" (deliberately misspelled) and "metaphysics of presence," so I agree: he's not about power relationships. That's Foucault.

My reply was designed to "flex" a bit by throwing out some central Derridean concepts—my way of saying "don't fuck with me if you think you can get into a pissing contest about Derrida." I also tried to be conciliatory, affirming that Derrida's focus was not on power relationships. I ended my reply by reminding my dunderheaded reader that, as I'd said initially, power relationships are a Foucaultian thing. If, at this point, my respondent decides to pursue the matter because he still somehow thinks I'm wrong about something, well, I don't plan to engage further because I'll know, at that point, that the guy is just a troll who thinks he knows something he doesn't.