Lilliana Mason. Uncivil Agreement: How Politics Became Our Identity. Chicago: University of Chicago Press. 2018. 192 pp. $105.00 (cloth). $20.00 (paper)

Lilliana Mason’s new book, Uncivil Agreement: How Politics Became Our Identity, has made—and will continue to make—a big splash in both the academic and media worlds. The attention is well deserved, as the book offers an explanation for why American politics has become so vitriolic in recent years. Mason argues that scholars have missed an important dimension of partisan sorting. Previous work on this topic explores issue-based sorting—the...