I beleive he is either the House or Senate Historian. I caught him the second after he was introduced so I'm not 100% sure.
That "intense pressure" to increase the number of speakers came from libs (Pelosi, Clinton) wanting to barge in. I heard O'Reilly say as of now there was no evidence that clinton had even said he was "angry and disappointed" at not being asked to speak. Clinton's CYA now, I suppose, w/the help of O'R.