I think I can see Chomsky's rationale. Unlike many on this list and elsewhere, he is aware that only mass movements and direct action make a significant difference. His hope, then, may each time be that before the inevitable drift to the right of electoral politics such a movement will emerge. That would correspond to the " radical change of some sort" I mentioned in my first post. Of course the likelihood of such a movement is lessened if every four years most those who might help bring it into existence desert politics for electoral day-dreaming.
Carrol