Donald Trump has, on more than one occasion, used his Twitter account to threaten violence on a scale the rest of us, not being presidents ourselves, can never hope to achieve. You and I don’t have a nuclear button on our desks-​-​even a very small one. Even when he’s not telling North Korea how close he is to incinerating them, however, he’s making explicit threats against political rivals, threats his position in the chain of command and his access to men with guns make a good deal more credible than when an angry video gamer all-​caps shouts at a female Twitter celebrity.