Ezra Klein authored this book, and he hosts my favourite podcast, The Ezra Klein Show, in which he regularly discussed the ideas that appear in this book. A surprising amount of his podcast guests actually feature in the book, even those you’d think have little to do with USA politics.
The book is competently written and thoroughly researched. You certainly get the impression Klein has done his homework and knows his shit. I think his structural polarization theory outlined in the book is very strong. It’s already been validated multiple times during the Trump presidency, and I think it will continue to be one of the most important political ideas in the coming decade, as polarization is getting even worse.
At times, he weakens his thesis’ persuasiveness by avoiding arguments that aren’t predominantly referencing to sociological or political science research. Klein gives the impression that he’d have no confidence in his ideas if he couldn’t find some usable study saying that X % of participants exbihited Y treatment response. It’s possible to reduce the pop-sci argumentation and instead rely on the explanatory power of his theories, similar to what Herman & Chomsky did in Manufacturing Consent.
The other major weaknesses in the book is that Klein does not have strong ideas about how corporate capitalist structures in media contribute to polarization. He definitely gestures at this problem, but it’s a much bigger problem than the book gives credit. He’s also quite light on anti-Capitalist analysis generally, for example the idea of the “wealthy ruling class stoking racial division to divide the working class” is given relatively short shrift in the book, though evidence abounds that this is the biggest contributor to polarization in the USA (see Dark Money, The New Jim Crow, A People’s History of the United States).