A critical, revelatory examination of teachers unions' rise and influence in American politics. As most American labor organizations struggle for survival and relevance in the twenty-first century, teachers unions appear to be an exception. Despite being all but nonexistent until the 1960s, these unions are maintaining members, assets—and political influence. As the COVID-19 epidemic has illustrated, today’s teachers unions are something greater than mere labor organizations: they are primary influencers of American education policy. How Policies Make Interest Groups examines the rise of these unions to their current place of influence in American politics.     Michael Hartney details how state and local governments adopted a new system of labor relations that subsidized—and in turn, strengthened—the power of teachers unions as interest groups in American politics. In doing so, governments created a force in American politics: an entrenched, subsidized machine for membership recruitment, political fundraising, and electoral mobilization efforts that have informed elections and policymaking ever since. Backed by original quantitative research from across the American educational landscape, Hartney shows how American education policymaking and labor relations have combined to create some of the very voter blocs to which it currently answers. How Policies Make Interest Groups is trenchant, essential reading for anyone seeking to understand why some voices in American politics mean more than others.