The only reasons he didn't go off the rails with McCain are because his handlers had better control in the first campaign, he himself hadn't burned out, his narcissism hadn't been fed in the way it has in the last 4 years, and McCain never really gave him a real fight. He was buoyed up in the first campaign on the wave of his own magnificence, as he saw it and as everyone in the world kept telling him.
I hear that kind of thinking a lot. I have a slightly different take. I have known people in the profession of Drug rehabilitation. One man, who was my very good friend, was the administrator of a program. A long time ago he asked me to, and I agreed, to take some of the ones back who were successfully treated into my home as roommates.
I had on occasion the opportunity to attend a number of large AA meetings and sat and talked with recovering addicts of various substances. Obama's defensiveness, is derisiveness, is braggadocio, his seemingly outrageous language and posture remind me very much of a drug addict.
My feeling is that this campaign has created more stress than he is comfortable with. He cannot take his free time to freeload on the golf course, kick-back in front of his TV, or light up with this favorite substance of abuse. So- he feels a sort of frustration: an anger.
It's just a theory, but I think there are times we have caught him high in public. Now he can't, and he is pissed. Listen to him if he goes off script. Listen for the slip of anger. Look at the tightness in him. He wants revenge. He wants to make someone pay. He wants to get in their face.