As the author, Ezra Klein constructs an argument diagnosing the increasing polarization within the American political system, explains why it is problematic given the US system of governance, theorizes why it is worsening, and offers some suggestions to address this political crisis. Drawing upon academic research in political science, sociology, and psychology, Klein adds his insights as a political journalist and describes complex political dynamics in accessible language.

As a political journalist for over 15 years, Klein has the experience to write this work on US politics. He has served as a newspaper reporter, a magazine writer, an opinion columnist for The New York Times and The Washington Post, an MSNBC analyst, and an editor. He is a co-founder of Vox, an explanatory news organization that reaches 50 million people each month. In the work, Klein summarizes the findings of several academic scholars; with a degree in political science from the University of California at Los Angeles, Klein is qualified to review and present those findings. Why We’re Polarized has received many favorable reviews from reputable organizations, such as Foreign Affairs, and became a New York Times bestseller.

Klein begins the book by asking how Donald Trump, who broke multiple political norms, performed so similarly to more traditional Republican candidates in the recent past.