The book includes substantive and brilliant chapters on the major challenges facing the country: racial strife, the dominance of tech companies, drug cartels, predatory crime, religious pluralism in public schools. In the end, though, the narrative comes back to the subject of Donald Trump. Is he capable of taking on these challenges? His 'political persona,' writes Mr. Barr on the book’s final page, 'is too negative for the task ahead.' He’s right..