The terms of 35 senators will expire in January 2009, and many of them are expected to seek reelection. Given the slight majority, look for many of these races to be competitive.
| Democrats | |||
| State | Senator | Winning % in Last Election |
NFIB Voting Record (109th Congress) |
| Arkansas | Mark Pryor | 54 percent | 22 percent |
| Delaware | Joe Biden | 58 percent | 25 percent |
| Iowa | Tom Harkin | 54 percent | 0 percent |
| Illinois | Dick Durbin | 60 percent | 0 percent |
| Louisiana | Mary Landrieu | 52 percent | 44 percent |
| Massachussetts | John Kerry | 80 percent | 0 percent |
| Michigan | Carl Levin | 61 percent | 0 percent |
| Montana | Max Baucus | 63 percent | 38 percent |
| New Jersey | Frank Lautenberg | 54 percent | 0 percent |
| Rhode Island | Jack Reed | 78 percent | 11 percent |
| South Dakota | Tim Johnson | 50 percent | 44 percent |
| West Virginia | Jay Rockefeller | 63 percent | 17 percent |
| Republicans | |||
| State | Senator | Winning % in Last Election |
NFIB Voting Record (109th Congress) |
| Alabama | Jeff Sessions | 59 percent | 100 percent |
| Alaska | Ted Stevens | 78 percent | 100 percent |
| Colorado | Wayne Allard* | 51 percent | 100 percent |
| Georgia | Saxby Chambliss | 53 percent | 100 percent |
| Idaho | Larry Craig* | 65 percent | 89 percent |
| Kansas | Pat Roberts | 83 percent | 100 percent |
| Kentucky | Mitch McConnell | 65 percent | 100 percent |
| Maine | Susan Collins | 58 percent | 100 percent |
| Minnesota | Norm Coleman | 50 percent | 89 percent |
| Mississippi | Thad Cochran | 85 percent | 100 percent |
| Mississippi | Roger Pickering | N/A | N/A |
| Nebraska | Chuck Hagel* | 83 percent | 100 percent |
| New Hampshire | John Sununu | 51 percent | 100 percent |
| New Mexico | Pete Domenici* | 65 percent | 89 percent |
| North Carolina | Elizabeth Dole | 54 percent | 100 percent |
| Oklahoma | Jim Inhofe | 57 percent | 100 percent |
| Oregon | Gordon Smith | 56 percent | 100 percent |
| South Carolina | Lindsey Graham | 54 percent | 89 percent |
| Tennessee | Lamar Alexander | 54 percent | 100 percent |
| Texas | John Cornyn | 55 percent | 100 percent |
| Virginia | John Warner* | 83 percent | 100 percent |
| Wyoming | Mike Enzi | 73 percent | 100 percent |
| Wyoming | John Barrasso | N/A | N/A |
* Retiring
