If a shark, by popular myth, has to keep swimming to stay alive, Trump has to keep talking, keep emitting sound and spouting fury. He has no off-switch, no mute button. His rambling off-the-cuff remarks are like the whine of a circular saw cutting tile all day, a television blaring through the wall at night. No President in modern memory has made more noise. Yet no President in modern memory has given fewer speeches to lesser effect.