You're right.
It seems his air of confidence arises from his ability not to listen to what an opponent says, but simply identify the theme and regurgitate stock replies.
Two things are lacking in his current appearances:
He doesn't take the time to prepare-- I've always wondered about his disappearances prior to major addresses, sometimes for several days, then emerging on some podium somewhere to deliver what MSNBC would hail as one of the greatest speeches of all time.
The second thing: his writers are mediocre, compared to the one he had in '08, and Rahm Emanual is no longer with him. Rahm is a scumbag, but he's shrewd-- perhaps the real power behind him in '08.
I didn’t think of Emanuel. He lost Axelrod, too.
But what impressed me the most about his debate performance was that it required a sustained effort to listen to what he was actually saying, versus thinking, “he sounds like he knows what he’s talking about... What did he just say?”
He never stumbled, and the blather flowed effortlessly.
He seems to slip whenever he answers direct questions, rather than when he speaks extemporaneously. He covers this weakness by filibustering.