Senators who are members of each major political party organize themselves into party conferences, sometimes called party caucuses. (Independent senators may, and frequently do, choose to join one of the major-party conferences.) Party conferences elect floor leaders, determine many committee assignments, and set legislative agendas. The Democratic floor leader serves as chair of the party conference, but the Republicans—in a practice dating back to 1945—divide those duties, electing one person to serve as conference chair and another to serve as floor leader.
| Senator | Term |
|---|---|
| John W. Stevenson (D-KY) |
|
| William A. Wallace (D-PA) |
|
| George H. Pendleton (D-OH) |
|
| James B. Beck (D-KY) |
|
| Arthur P. Gorman (D-MD) |
|
| David Turpie (D-IN) |
|
| James K. Jones (D-AR) |
|
| Arthur P. Gorman (D-MD) |
|
| Joseph C. S. Blackburn (D-KY) |
|
| Charles A. Culberson (D-TX) |
|
| Hernando D. Money (D-MS) |
|
| Thomas S. Martin (D-VA) |
|
| John W. Kern (D-IN) |
|
| Thomas S. Martin (D-VA) |
|
| Oscar W. Underwood (D-AL) |
|
| Joseph T. Robinson (D-AR) |
|
| Alben W. Barkley (D-KY) |
|
| Scott W. Lucas (D-IL) |
|
| Ernest W. McFarland (D-AZ) |
|
| Lyndon B. Johnson (D-TX) |
|
| Michael J. Mansfield (D-MT) |
|
| Robert C. Byrd (D-WV) |
|
| George J. Mitchell (D-ME) |
|
| Thomas A. Daschle (D-SD) |
|
| Harry Reid (D-NV) |
|
| Charles E. Schumer (D-NY) |
|
