Why do legislators reject compromise, at the risk of forfeiting tangible policy gains? This is the puzzle that Sarah E. Anderson, Daniel M. Butler, and and Laurel Harbridge-Yong address in their new “problem-oriented” (p. 130) study of legislative compromise.

This question is both timely and relevant, given that many of the most pressing policy challenges in the United States—such as climate change, economic inequality, immigration, education, and health care—are year after year tabled by lawmakers who are unable (or unwilling) to agree on legislative solutions.

While this question is not new, the authors’ answer is a novel one. Conventional wisdom holds that gridlock stems from fundamental ideological differences between legislators. By contrast, Anderson, Butler, and Harbridge-Yong make a powerful case that legislators strategically reject compromise, not because they disagree in substance but because they fear retribution from high-information ideological voters, who punish copartisan legislators in primary elections for working with the opposition.

To show the effects of voter retribution on legislators’ willingness to accept compromise with the other party, Anderson, Butler, and Harbridge-