If you want an example of Liberals treating Rush as the leader of the Conservative movement, you can simply link to Media Matters and be done with it.
The problem is that the GOP makes it so damn easy to use Rush against them. Rush is a performer, and says stuff to sell advertising. The advertisers are the folks that forced him to apologize this weekend. Of course he's going to say bombastic things if it'll get him more attention.
However, the GOP enables him by ACTIVELY courting Limbaugh's blessing every 4 years. If they'd ignore him, like they do Savage or Coulter or Beck, then what Rush says wouldn't be so big an issue in the actual election.
The GOP is setting up Hannity for a similar position. Hannity is every bit bombastic as Rush, and the GOP actively seeks his approval when the elections roll around. Once Rush is retired or off the air, it'll be Hannity that the Left trots out to embarrass the Right.
The truth is the Left doesn't need Rush to embarrass the Right. Not Rush nor Hannity nor Coulter (despite the fact that these bon vivants are plenty embarrassing on their own).
Nope! There is no need for a proxy when it comes time for the embarrassment of the Conservatives in America today. They seem to be doing fine all by themselves.
But so far as Rush is concerned, all one has to do is listen to his program and read the fawning words of his sycophants here on USMB to get a handle on the Limbaugh effect on far right politics. Within minutes of Limbaugh's pronouncement that women who seek contraceptive devices are, indeed sluts, the very same words were blossoming like mushrooms from this load of horseshit.
The Big Voice on the Right is how Limbaugh bills himself. A sounding brass for imbeciles and the unlearned is what he actually is.