Let me issue the standard disclaimer of psychiatrists who discuss the mental health of public figures: I have not personally examined President Trump. Now, let me put to rest the concerns of Sen. Al Franken and political commentators John Oliver and Andrew Sullivan and anyone else who publicly or privately has questioned the president’s sanity: Donald Trump is stone cold sane. When a man acquires billions of dollars through complex real estate transactions, invests in many countries, goes on to phenomenal success in television and turns his name into a worldwide brand, it is very unlikely that he is mentally...