Here's a pretty good column on the abundant hypocrisy surrounding this singling out of Limbaugh for the gallows tree.

It doesn't spare any punches for Limbaugh, but honestly acknowledges the abundant audacity of the left to be so shocked at his verbiage coupled with the lame-o reasons why Limbaugh saying something is so much worse than if they say it.

It's Like Totally Different When a Liberal Blowhard Guy Calls a Conservative Woman a Twat! - Hit & Run : Reason Magazine