Some of Robert Jensen's piece regarding liberals who attack the left (Emphasis is mine):
"Some of my best friends are liberals. Really. But I have found it is best not to rely on them politically.
Bashing the left to burnish credibility in mainstream circles is a time-honored liberal move, a way of saying 'I’m critical of the excesses of the powerful, but not like those crazy lefties.'
For example, during a discussion of post-9/11 politics, I once heard then-New York University professor (he has since moved to Columbia University) Todd Gitlin position himself between the “hard right” (such as people associated with the Bush administration) and the “hard left” (such as Noam Chomsky and other radical critics), implying an equivalence in the coherence or value of analysis of each side. The only conclusion I could reach was that Gitlin -- who is both a prolific scholar and a former president of Students for a Democratic Society -- either believed such a claim about equivalence or said it for self-interested political purposes. Neither interpretation is terribly flattering for Gitlin."