The book and its prequel are the outcomes of the author's addiction to The New York Times. More specifically, they are the results of his habit of commenting on Times stories in which he spotted errors or erroneous opinions.
Ever since Donald Trump became President of the United States, the author also considered it his responsibility to point out the lies Trump has been habitually uttering and blunders he has been continually committing. The reason, as the author spells out in the preface to the book, is that when the head of state of the most powerful country in the world uses his bully pulpit to spread falsehoods, the gullible among the general public tends to believe them as true, with disastrous consequences not only to the U.S, but to the whole world.