What Alterman, Rorty, etc. are afraid of can't be the specter of postmodernism haunting the classrooms + dorm rooms of elite universities. Whether they are conscious of it or not, their fear must arise out of a possibility that national pride and the Democratic Party might suffer from, for instance, kids learning about the dirty history of cold war liberalism--and the union bureaucrats' complicity in it--that didn't think twice about sacrificing workers--the third world people who dared to contemplate an alternative to capitalism as well as the working-class Americans who were used as grunts--for the sake of getting a piece of action generated by the military-industrial complex.
Kids who want justice for Mumia, more likely than not, will learn about the FBI and its war against black and other radicals (or even 'moderates' like MLK), police brutality, how racism has helped those who wanted the 'war on crime' and prison labor, how the 'war on drug' has been used to gain 'consent' to repression here and abroad.
Hey, kids might even read books by subversive white guys like Chomsky and Michale Parenti! Imagine that! 'Can't allow that to happen,' think Alterman, Rorty, and the Undead of cold war liberalism. (Ever wonder why the undead in horror films are always white?) So they are working hard to erase the word 'imperialism' from public discourse. Food for thought after the Memorial Day weekend.
Yoshie