Democrats voting on 1999-98 | ||
| Daniel Akaka | YES | HI Democrat Jr Senator |
| Evan Bayh | NO | IN Democratic Jr Senator |
| Jeff Bingaman | YES | NM Democrat Jr Senator |
| Barbara Boxer | YES | CA Democratic incumbent |
| John Breaux | YES | LA Former Democratic incumbent; retired 2004 |
| Richard Bryan | NO | NV Democrat Jr Senator (Former) |
| Robert Byrd | YES | WV Democrat Sr Senator |
| Max Cleland | NO | GA Democratic Senator (Former) |
| Kent Conrad | YES | ND Democrat Sr Senator |
| Tom Daschle | YES | SD Former Democratic Senator (defeated 2004) |
| Chris Dodd | NO | CT Democratic incumbent |
| Byron Dorgan | YES | ND Democratic incumbent |
| John Edwards | YES | NC Former Democrat Senator; retired to run for President, 2004 |
| Russell Feingold | YES | WI Democratic incumbent |
| Dianne Feinstein | YES | CA Democrat Sr Senator |
| Bob Graham | NO | FL Former Democratic Senator; retired 2004 |
| Fritz Hollings | YES | SC Former Democratic Sr Senator; retired 2004 |
| Daniel Inouye | NO | HI Democratic incumbent |
| Ted Kennedy | YES | MA Democrat Sr Senator |
| Bob Kerrey | YES | NE Former Democrat Senator |
| Herbert Kohl | YES | WI Democrat Sr Senator |
| Patrick Leahy | NO | VT Democratic incumbent |
| Joseph Lieberman | NO | CT Democratic Jr Senator; Gore's VP nominee; ran for Pres. 2004 |
| Blanche Lambert Lincoln | YES | AR Democratic incumbent |
| Barbara Mikulski | YES | MD Democratic incumbent |
| Pat Moynihan | YES | NY Democrat Senator (Former) |
| Patty Murray | YES | WA Democratic incumbent |
| Harry Reid | YES | NV Democratic incumbent |
| Charles Robb | NO | VA Democrat Senator (Former) |
| Paul Sarbanes | YES | MD Democrat Sr Senator |
| Charles Schumer | YES | NY Democratic incumbent |
| Bob Torricelli | YES | NJ Democrat Jr Senator |
| Paul Wellstone | YES | MN Democrat Senator (Former) |
| Ron Wyden | YES | OR Democratic incumbent |
Republicans voting on 1999-98 | ||
| Spencer Abraham | YES | MI Republican Senator (Former) |
| John Ashcroft | YES | MO Republican Senator (Former) |
| Robert Bennett | YES | UT Republican incumbent |
| Kit Bond | YES | MO Republican incumbent |
| Sam Brownback | YES | KS Republican incumbent |
| Jim Bunning | YES | KY Republican incumbent |
| Conrad Burns | YES | MT Former Republican Senator (MT, 1989-2007) |
| Ben Nighthorse Campbell | YES | CO Former Republican incumbent; retired 2004 |
| John Chafee | YES | RI Republican Senator (Former) |
| Paul Coverdell | YES | GA Republican Senator (Former) |
| Michael Crapo | YES | ID Republican incumbent |
| Mike DeWine | NO | OH Republican Sr Senator |
| Peter Fitzgerald | YES | IL Former Republican incumbent; retired 2004 |
| Bill Frist | YES | TN Republican Jr Senator |
| Slade Gorton | YES | WA Republican Senator (Former) |
| Phil Gramm | YES | TX Former Republican Senator |
| Rod Grams | YES | MN Republican Senator (Former) |
| Chuck Grassley | YES | IA Republican incumbent |
| Judd Gregg | YES | NH Republican incumbent |
| Orrin Hatch | NO | UT Republican Sr Senator |
| Jesse Helms | YES | NC Former Republican Sr Senator |
| Tim Hutchinson | YES | AR Republican Sr Senator |
| Kay Bailey Hutchison | YES | TX Republican Jr Senator |
| James Inhofe | YES | OK Republican Sr Senator |
| Jon Kyl | YES | AZ Republican Jr Senator |
| Trent Lott | YES | MS Former Republican Senator (MS, 1989-2007) |
| Richard Lugar | NO | IN Republican Sr Senator |
| Connie Mack | NO | FL Former Republican Senator |
| John McCain | NO | AZ Republican incumbent |
| Frank Murkowski | YES | AK Republican Senator (Former; now Governor) |
| Don Nickles | YES | OK Former Republican incumbent; retired 2004 |
| William Roth | YES | DE Former Republican Senator |
| Rick Santorum | YES | PA Republican Jr Senator |
| Richard Shelby | YES | AL Republican incumbent |
| Bob Smith | YES | FL Republican challenger; former NH Senator; Constitution Party |
| Olympia Snowe | YES | ME Republican Sr Senator |
| Arlen Specter | YES | PA Republican incumbent |
| Craig Thomas | YES | WY Republican Sr Senator |
| Fred Thompson | YES | TN Republican Sr Senator |
| Strom Thurmond | YES | SC Former Republican Senator |
| George Voinovich | YES | OH Republican incumbent |
Independents voting on 1999-98 | ||
| Jim Jeffords | YES | VT Independent Jr Senator |
| Stuart Starky | YES | AZ 2004 former Democrat challenger; also ran for Senate in '00 |
| Democrats:
YES 25; NO 9
Republicans: YES 36; NO 5 Independents: YES 2; NO 0 |