You totally left out Cheney and Limbaugh.
indeed - and Coulter, Hannity, Beck, Malkin, Fox News...
The one thing all of these figures have in common, (other than conservative leanings in various degrees) is none of them matter. None of these people make laws, raise or lower taxes, start wars, or direct policy.
They just express opinions.
Granted, we do make fun of the left's commentators - Olbermann, Maddow, Moore, etc etc, but one isn't going to find endless threads about how these commentators are war criminals, should have their assets frozen, and get 'frog-marched to the Hague'
All politicians have term limits - they are usually referred to as 'elections'.
All political commentators do as well - those limits are called 'ratings'.
The short of it is, if you don't get the numbers, you lose your job. Instead of trying to take away opportunity for the people they disagree with, they should work on finding effective people to express their views. Unfortunately (for them), their biggest people are really quite unlikeable. Id say their most likable was Stewart - but he is a Comedian - and now that Bush is no longer in office, he has run out of material that the left likes. Remember when there were dozens of Daily Show threads a day at DU ? Now, not so much...