Part of the reason he talks back so much (nearly doubling the initial length of his speech, in this case) is that he likes the sound of his own voice. But there is something else: Clinton is such a master of rhetorical strategy—he commands such innate and reflexive mastery of what makes the spoken word resonate—that he cannot help but improve his speech as he gives it. He doesn’t ad lib in the sense that extras in a movie have a restaurant conversation. He improvises, in the sense that Miles Davis or Beethoven would come up with an enduring work of art on the spot.
And from there it goes into a nice play-by-play showing exactly how Clinton played off the teleprompter during different parts of the speech. Great piece about a great speech, and a truly gifted public speaker. If you haven’t seen it yet, do.
Bonus: Hendrik Hertzberg agrees.