How about adopting Chomsky's stance here? He is a left-wing anarchist & has impeccable anti-Stalinist credentials, no? He even has anti-Leninist credentials, if that's what you want. In his works, though, he _never_ gives equal space to criticisms of American imperialism and America's official enemies; it is always clear in his works _which_ is the main target. When the Soviet Union existed, he used to put in slyly kind remarks for it here and there, not because he was siding with the KGB against Soviet workers, but because he was out to skewer American imperialists even more by showing how they compared unfavorably to the Soviets.
Nowadays, this traditional emphasis of American leftists (as exemplified by Chomsky) has become reversed, it seems to me.
Lastly, I've never heard Chomsky slinging "Stalinist," "authoritarian," etc. as common epithets to put down leftists (as is done on LBO, despite the fact that the Soviet Union is a *thing of the past*)! Leave it to the likes of Horowitz to do such a silly thing.
Yoshie