Neither a polemic nor a lament, this book offers a clear framework for understanding everything from Trump's rise to the Democratic Party's leftward shift to the politicisation of everyday culture. Klein shows how and why American politics polarised in the twentieth century, what that polarisation did to Americans' views of the world and one another, and how feedback loops between polarised political identities and polarised political institutions drive the system toward crisis. This revelatory book will change how you look at politics, and perhaps at yourself.