Some of the smartest thinkers on problems at home and around the world are university professors, but most of them just don’t matter in today’s great debates.

The huffing and puffing in response to this by academics is as annoying as the piece itself. The older generation of "public intellectuals" were not all academics and those who were were not defined by academic status. Complaints about intellectuals retreating into the ivory tower are not requests for them to come back down from the mountain. Edmund Wilson and Irving Howe were critics, not professors, and certainly not professors of political "science". Chomsky's activism is the activism of a citizen. He's very specific in separating his politics from his day job (more academic public intellectuals here).

Academic discussion of politics as such is left to political scientists and experts in "foreign policy". It's nationalist by definition. The Kennedy school educates new generations of bureaucrats.  Academic leftism, the politics of theory, I've covered enough.  At CT, Rakesh Bhandari in a comment, without mentioning that the majority of posters are from the UK, adds that no one on the site's mentioned the death of Stuart Hall.

"Public Intellectual"

I've asked this before: What's a "private" intellectual?