You have long championed the virtue of psychoanalysis against churlish & curmudgeonly skeptics like Carrol, and your eloquence has made me a convert, so here's my psychoanalytic reading of your relationship with "sectarians."
A: You feel ashamed & embarrassed to find your thoughts clothed in the untutored rhetoric of "sectarian" autodidacts. Familiar made strange -- uncanny.
B: It's like running into your urbane friends when you are escorting your old-fashioned country cousin around New York City. You have been a New Yorker for decades, but you fear your Garden State roots might still show. You must act as if you didn't know your country cousin. In case you'd be cast out as "one of them." Likewise, your shame makes you distance yourself from "sectarians," making fun of them before others get around to it.
C: Tragically, it's only "sectarians" who actually agree with you, for neither non-Marxist union members (be they officials or rank & file) nor Brad DeLongs think that American imperialism exists and must go and that capitalism must be abolished, though they might "listen to" you respectfully. You mourn your rejection, and the rejection by the "mainstream" is abjected -- and the abjects are "sectarians," not you.
D. "Practically everything I write on political economy is influenced by Marx, but I rarely use the received language. (I do like throwing in 'bourgeoisie' or 'capitalist hyena press' every now and then, for shock value.) I find people listening to me, and maybe even agreeing with me, who might well have stopped listening if I'd sounded like a party paper." Why doesn't anyone speak like me? The mirror stage, the imaginary, narcissism, and aggression. Down with Sectarians!
Cruelty -- your name is psychoanalysis. M. Henwood, c'est moi! Hypocrite lecteur, - mon semblable, - mon frère!
Yoshie