I could do with some of that self confidence.
I think the problem is that it is bordering on self-delusion. The only way to be that confident is to lack self-awareness, which I do think is one of the problems he has. He does not seem capable of recognizing that some of his actions and arguments are unconvincing (or even harmful to his case). Doubling down doesn't help, nor does his stubborn determination to win at any cost, because he only really knows one way to deal with the pressure, which is to launch one massive attack after another. If your reaction to being called a bully is to bully even harder...