Yes, Howard Dean.
That speech became known as the "I have a scream" speech.
![ROFL :rofl:](http://www.intensitysquared.com/Smileys/default/rofl.gif)
BTW, he didn't slip in the polls after the speech, he slipped before then and had just lost the Iowa primary.
It was intended to be a speech to "rally the troops" and continue fighting on to the next primary election.
It ended up being his swan song.