This single paragraph gives the best summary I can find:
I'll grant that Rove's parting shot about the "motives of liberals" was over the top. Still, for about five years now liberals (by which I mean most Democrats) have been running around the country with a big, broad brush calling conservatives (by which they mean most Republicans) evil, extremists, crooks, liars, thieves, theocrats, bigots, homophobes, racists, sexists, etc. and impugning their motives in any number of other ways on virtually a daily basis. Karl Rove calls liberals a bunch of sissies a single time and Democrats and the media have a collective seizure of apoplexy.
As Glenn Reynolds of Instapundit would say: Heh.