How politically powerful is business in American politics? Does the political power of business distort the quality of democratic representation? This chapter reviews the literature on these vital questions, discussing selected studies in political science, sociology, history, and other fields. It finds that assessments of business influence in American politics have varied considerably over time, but it also observes there has been a broad turn in recent scholarship toward the notion that business is “more equal” than other groups in the American political system. A small but growing number of studies—especially studies focusing on politics in our time—has begun to provide credible evidence of business influence. We have also seen the introduction of some exciting new ideas about the ways that business influence, economic inequality, and political representation may be theoretically connected. But definitive conclusions remain elusive. We do not really know whether business is disproportionately powerful and how business influence affects the performance of American democracy. The chapter concludes with some suggestions about the kind of studies that are needed going forward.