Mailer’s novel is probably the most masturbatory thing I have ever read. For the first nine-tenths of the book Mailer champions himself as protagonist and narrator, detailing the events of the 1967 March on the Pentagon from his own personal and very biased perspective. He does not shy away from his prejudices, but rather leans into them, reveling in his sexism, racism, and homophobia.
The last portion, The Novel as History, takes a wider view, novel-izing with some sense of narrative style the events that led up to the March, and describing all parts of the March itself, especially those that Mailer himself did not participate in. The work as a whole is a prime example, perhaps one of the first, of New Journalism, and plays fancifully with ideas of objectivity and the lines between narrative and history. It is possible that these playings would in fact be interesting if they had been written by someone slightly less ego-maniacal and outright rude. Who knows.