McCain's mannerisms
The scariest thing about him is his obvious seething anger. It is not difficult to see him repressing the anger as he speaks. Watch ten minutes of any debate where he is being challenged on one of his quotes, or even better, watch an appearance on one of the many talk programs. You will notice if you watch (and not even intently), the same pattern emerge when he is pressured. He will clench his teeth in a pseudogrin (grinding his teeth is probably a better way to describe it), clench his fists (usually under a table or podium, although I've seen him do it in the open when he had nowhere to hide his hands), and laugh - always with the half chuckle or "laugh". Anyone who knows anything about basic body language knows that it is requiring McCain a lot of effort simply to prevent himself from lashing out. I realize the media has mastered the art of image manipulation, but on this one, their angle has a ring of truth. He truly does have an anger problem.