I think what separates the good from the truly charismatic speakers is the perceived level of comfort.
They might be terrified and anxious on the inside but if the crowd only sees a relaxed and calm persona it is extremely impressive.
I was at a stand up comedy gig recently and with the warm up acts you could sense their nerves.
You could almost see them trying to remember the next line. Making sure they said every word perfectly.
But with the headline act, it looked effortless.
It was so casual, it was as if we were in conversation with him.
The extreme levels of comfort enhanced his charisma to the nth degree.
Thomas Duggan 