Leading political scientists analyze the presidency of Donald Trump and its impact on the future of American politics In virtually all respects, the Trump presidency has disrupted patterns of presidential governance. However, does Trump signify a disruption, not merely in political style but in regime type in the United States? Assessing Trump's potential impact on democratic institutions requires an analysis of how these institutions—including especially the executive branch—have developed over time as well as an examination of the intersecting evolution of political parties, racial ideologies, and governing mechanisms. To explore how time and temporality have shaped the Trump presidency, editors Zachary Callen and Philip Rocco have brought together scholars in the research tradition of American political development (APD), which explicitly aims to consider how interactions between a range of institutions result in the shifting of power and authority in American politics, with careful attention paid to complex processes unfolding over time. By focusing on the factors that contribute to both continuity and change in American politics, APD is ideally situated to take a long view and help make sense of the Trump presidency. American Political Development and the Trump Presidency features contributions by leading political scientists grappling with the reasons why Donald Trump was elected and the meaning of his presidency for the future of American politics. Taking a historical and comparative approach—instead of viewing Trump's election as a singular moment in American politics—the essays here consider how Trump's election coincides with larger changes in democratic ideals, institutional structures, long-standing biases, and demographic trends. The Trump presidency, as this volume demonstrates, emerged from a gradual unsettling of ideational and institutional lineages. In turn, these essays consider how Trump's disruptive style of governance may further unsettle the formal and informal rules of American political life. Contributors: William D. Adler, Gwendoline Alphonso, Julia R. Azari, Zachary Callen, Megan Ming Francis, Daniel J. Galvin, Travis M. Johnston, Andrew S. Kelly, Robert C. Lieberman, Paul Nolette, Philip Rocco, Adam Sheingate, Chloe Thurston.