That's the opposite way I've heard blob used. Usually it refers to the bureaucracy, think tanks etc. that drive US imperial policy. It's described as a blob because, like the monster in the movie, it has no head and just pushes forward relentlessly aligning other elements of the state with itself.

Edit: just saw your edit. It doesn't refer just to libs but the entire engine driving the empire. This includes the military, intelligence agencies, think tanks, and defense industry. These groups in turn have successfully coopted most of the media (usually thru being special sources) and electeds (often thru pork barrel). These groups make up the blob.