Scholars who study American elections tend to divide into two camps. One, to which this reviewer belongs, sifts for evidence of intelligence and rationality in the aggregate decisions of voters. With Democracy for Realists, Christopher H. Achen and Larry M. Bartels place themselves decidedly in the opposite camp. They see an electorate that is unprepared for its job in a democracy.

Achen and Bartels dismiss the “folk theory” of democracy, the idea that voters know best and elect officials who follow their will. Rather, they depict ordinary people as having little interest or competence regarding politics, a subject that is too complicated even for the best of us. When Achen and Bartels’s citizens are stirred to act politically, such as when they feel obliged to cast votes, they consult their emotions more than facts and reason. What keeps them from becoming totally unmoored politically is their group allegiances based on social identity.

Several chapters delve into the public’s haplessness when it comes to retrospective voting, whether concerning the economy or disasters such as shark attacks. Their centerpiece example is about how angry voters in New Jersey shoreline counties punished the Woodrow Wilson administration in 1916 for not preventing the many shark attacks off the New Jersey coast that summer. Achen and Ba