text:  Most of the time, you don't know about a defining moment until after it happens. But tonight, there will be defining moments. Something is going to happen that is going to move the direction one way or another. This is a pivot point, and it's designed to be, because that's why Biden had to do this. He had to answer the critics. If he had not shown he could handle Trump, I don't know that he'd have made it as the nominee to the convention.