Democrats participating in 03-S875 | ||
| Evan Bayh | s1o | IN Democratic Jr Senator |
| Maria Cantwell | s1o | WA Democrat Jr Senator |
| Hillary Clinton | s1o | NY Democrat Jr Senator |
| Kent Conrad | s1o | ND Democrat Sr Senator |
| Jon Corzine | s1o | NJ Democrat |
| Tom Daschle | s1o | POTUS Democrat |
| Mark Dayton | s1o | MN Democrat Jr Senator |
| Chris Dodd | s1o | CT Democratic incumbent |
| Byron Dorgan | s1o | ND Democratic incumbent |
| Richard Durbin | s1o | IL Democrat Sr Senator |
| Dianne Feinstein | s1o | CA Democrat Sr Senator |
| Tom Harkin | s1o | IA Democrat Jr Senator |
| Tim Johnson | s1o | SD Democrat Sr Senator |
| Ted Kennedy | s1o | MA Democrat Sr Senator |
| John Kerry | s1i | MA Democrat Jr Senator |
| Mary Landrieu | s1o | LA Democrat Sr Senator |
| Frank Lautenberg | s1o | NJ Democrat Sr Senator |
| Blanche Lambert Lincoln | s1o | AR Democratic incumbent |
| Barbara Mikulski | s1o | MD Democratic incumbent |
| Patty Murray | s1o | WA Democratic incumbent |
| Ben Nelson | s1o | NE Democrat Jr Senator |
| Mark Pryor | s1o | AR Democratic Jr. Senator |
| Harry Reid | s1o | NV Democratic incumbent |
| John Rockefeller | s1o | WV Democratic Jr Senator |
| Paul Sarbanes | s1o | MD Democrat Sr Senator |
| Charles Schumer | s1o | NY Democratic incumbent |
| Debbie Stabenow | s1o | MI Democrat Jr Senator |
| Ron Wyden | s1o | OR Democratic incumbent |
Republicans participating in 03-S875 | ||
| Wayne Allard | s1o | CO Republican Jr Senator |
| George Allen | s1o | POTUS Republican |
| Conrad Burns | s1o | MT Former Republican Senator (MT, 1989-2007) |
| Ben Nighthorse Campbell | s1o | CO Former Republican incumbent; retired 2004 |
| Lincoln Chafee | s1o | RI Republican Jr Senator |
| Susan Collins | s1o | ME Republican Jr Senator |
| John Cornyn | s1o | TX Republican Jr Senator |
| Michael Crapo | s1o | ID Republican incumbent |
| Mike DeWine | s1o | OH Republican Sr Senator |
| John Ensign | s1o | NV Republican Jr Senator |
| Judd Gregg | s1o | NH Republican incumbent |
| Chuck Hagel | s1o | NE Republican Jr Senator |
| Kay Bailey Hutchison | s1o | TX Republican Jr Senator |
| Rick Santorum | s1o | PA Republican Jr Senator |
| Olympia Snowe | s1o | ME Republican Sr Senator |
| Arlen Specter | s1o | PA Republican incumbent |
Independents participating in 03-S875 | ||
| Jim Jeffords | s1o | VT Independent Jr Senator |
| Democrats:
28
Republicans: 16 Independents: 1 |