I think it might have been the lil man who hit on this......the "far left" really has no power....the "far right" is another matter.
The far right has vast power. Entire TV networks, newspapers, Christian radio and TV.
I would agree that the mainstream left and those who might be aptly called center-left possess power. But the far left, none at all.
The exception would be in the blogosphere, where power seems to be pretty evenly distributed. It's basically up to the blogger to attract his or her supporters.
Shultz, Olbermann, Maddow, NY Times Opinion...