Rush’s defenders understand, I hope, that painting Rush as the all-powerful lord of conservatism before whom all else must submit was, in its origins, a political strategy devised by their enemies, right? So why are they jumping so quickly to prove that the argument is dead-on?
I think they're doing it because they can't help doing it, and that's because the strategy of using Rush as the voice of conservatism was a surprisingly shrewd one. Rush clearly wants the job, and influential conservatives are either afraid of him or agree with him, even if they find him at least somewhat offensive. And it's definitely true that there's nobody within the GOP with enough political capital to fight a war with Rush.
Portraying Rush as the face of conservatism was a strategy predicated on using the conservative movement's defining characteristics--ingroup loyalty--against the GOP. The strategy is simple: attack one of the totemic (and anathemic) media loudmouths of the Republican Party and force the GOP to either defend him, which makes him more prominent and hurts the GOP, or to denounce him, which alienates his 17 million or however many viewers. It's a no-win scenario, but you can't lose if you don't play, as The Wire tells us. But the conservative movement isn't headed by shrewd, savvy politicians--it's headed by wingnut bloggers who can't wisely avoid taking the bait and have a wee bit of a tendency to overreact to things. Hence, the GOP walking right into the Obama team's trap on Rush.
What this really shows is that the GOP is incredibly easy to manipulate. All you have to do is make a few stray remarks about Rush Limbaugh and the "Party of No" to make the entire Republican base go apeshit, to the point where Sean Hannity spends an entire segment on the president's mustard choice and the RNC will only refer to the party in power as the "Democrat Socialist Party". These people don't seem to get that Obama is a formidable opponent who has a tendency to turn his opponents into complete drooling idiots. I'd say that Obama's goal of marginalizing the Republicans is going pretty well--he's showing some traces of Nixonian shrewdness at this point (mostly in a good way).