Descriptions of Donald Trump's mental capacities range from "stable genius" (his words, as everyone knows by now) to some kind of mad dementia. It takes intelligence to become a successful businessman and to win the presidency as a relative outsider, say some; just listen to what he says, say others: his lack of knowledge about policy and policy making, his way of putting words together that sometimes challenges the label "stream of thought". The great linguist George Lakoff described Trump's way of speaking as very New York, very common folksy, and therefore politically smart; the great linguist Georger Pullum simply called it "Trump's aphasia". After looking at one excerpt of a campaign speech, Pullum ranted that "this nasty, racist, golden-quiffed, self-publicizing nutcase has barely a coherent thought in his head" and suggested that there was no sentence structure to analyze (I think the majority of linguists will disagree with the latter). Since Michael Wolff's claim that every single person who works with Trump doubts his capacity to carry out his job, questions about Trump's mental health finally became front page material.