The guy loves attention and the media tends to help him with that. I don't believe much he says. A lot of it is probably not legal and changing the law is not so easy. Tariffs get paid by the buyers so anyone buying imported goods may be worse off. The US won't suddenly re-grow a manufacturing industry.
Prepare for chaos!
there is no way Trump doesn't know this basic fact by now.. this is why I'm strongly leaning towards this whole thing being a distraction.