Now that I think about it, I think Bernie's mind is wavering too. Anytime he loses his train of thought he just reverts to his revolution/billionairs/millionaires.
The first question at the flint thing, he stood up (sign one he's distracting from being lost mid thought) then started talking about needing people to vote (sign two), then he says "to answer your question" (sign three return to lucidity briefly) "young people need to vote", and ends with "and that's the answer to your question".
So it might not be just a lack of substance in his rhetoric, I think he's been senile since he was like 25.