—Senate Majority Leader Mike Mansfield, 19621
Since 1913, U.S. senators have recognized one position among themselves as majority leader.2 The first incumbent, John W. Kern (D-IN), began the gradual process of converting the position into an office. He and his colleagues also set other precedents that, as this research will show, endure nearly a century later. Notwithstanding such a long period of experience, and despite the profusion of political scientists’ accounts of Congress and journalists’ daily observations of the legislative branch, no comprehensive study of the Senate majority leader has found its way into the annals of American politics. This book aims to correct the anomaly.