Watching the health care debate on C-SPAN I find Nancy Pelosi's speaking style to be jarringly disfluent, at least as much so as George W. Bush's ever was (or Sarah Palin for that matter) yet I don't recall Pelosi being as criticized as they were. My hotel internet connection is not fast enough for me to YouTube around for examples of Pelosi speaking extemporaneously, but I suspect you can find these examples easily and I suspect you'll see what I mean.
Is this a partisan issue? Are Republicans more likely to be criticized for speech errors than Democrats?
The folks at Language Log have discussed the politics of speech errors many times (see THIS post which includes links to many others) and it's worth quoting Liberman: "Everyone commits speech errors...and anyone who makes a big deal about particular examples is either a fool or a hypocrite."
My gut reaction is that there are many fools and hypocrites reporting on our politicians ... surely I am the first to uncover this rare gem of insight.
NOTE: I make no political point by bringing this up other than to ask if there is a statistical difference between the likelihood that a Republican figure will be criticized for speech errors and the likelihood that a Democrat will be criticized for speech errors. My intuition is that there is a difference, and that difference leans towards Republicans being more likely to be criticized. I caution the reader against trying to infer my own political beliefs from this post.