Not smug, angry, as well he should have been considering all of the questions were designed to put him on the defensive, and that smug ass next to him was calling him a liar constantly.
Someone, I forget who as I channel surfed, said Kerry was like the smartest kid in the class, but Bush was like the teacher who was tired of explaining the same things again and again. So, who thinks the "smartest kid in the class" is necessarily a positive thing with middle American voters? I'd go for the teacher who had to deal with the know-it-all student.
BTW, I can't imagine anyone watching that debate and seeing smugness in Bush. That sounds like what the Dems were saying about what Bush would do before the debate even began. A talking point? Spin? I'd bet on it.