Introduction and Methodological Notes 1

  Identifying House Leaders 2

  Identifying Senate Leaders 3

  Party Affiliation Designations 3

  Leadership Posts Excluded 4

House Positions: Descriptions and Historical Tables 4

  Speaker of the House of Representatives 4

  Party Floor Leader 7

  Party Whip 9

  Conference or Caucus Chair 11

Senate Positions: Descriptions and Historical Tables 16

  President Pro Tempore of the Senate 16

    Deputy Presidents Pro Tempore 23

    Permanent Acting President Pro Tempore 23

  Party Floor Leader 24

  Conference Chair 27

  Party Whip 29

Source Notes and Bibliography 31