The New York Times analyzed every public utterance by Mr. Trump over the past week.. The transcriptions yielded several powerful patterns, echoing the appeals of some demagogues of the past century.The dark power of words has become the defining feature of Mr. Trump’s bid for the White House to a degree rarely seen in modern politics; he relies on potent language to connect with, and often stoke, the fears and grievances of Americans.‘We vs. them’ creates a threatening dynamic, where ‘they’ are evil or crazy or ignorant and ‘we’ need a candidate who sees the threat and can alleviate it. Several historians watched Mr. Trump’s speeches last week, at the request of The Times, and observed techniques — like vilifying groups of people and stoking the insecurities of his audiences — that they associate with Wallace and McCarthy.