Some people have a knack, for example, of being able to tell...

Some people have a knack, for example, of being able to tell when someone's lying to them. They may not know what the truth is, but they can tell when someone is trying to lead them astray or sell them something shady. I think he had that ability to an amazing degree. I also think he thought, without saying it explicitly, that you can convince a crowd of something that's not true more easily than you can one person at a time.