# 2008 United States Senate elections

The 2008 United States Senate elections were held on November 4, 2008, with 35 of the 100 seats in the Senate being contested. 33 seats were up for regular elections; the winners were eligible to serve 6-year terms from January 3, 2009, to January 3, 2015, as members of Class 2. There were also 2 special elections, the winners of those seats would finish the terms that ended on January 3, 2013. The presidential election, which was won by Democrat Barack Obama, elections for all House of Representatives seats; elections for several gubernatorial elections; and many state and local elections occurred on the same date.
Going into these elections, the Senate consisted of 49 Democrats, 49 Republicans, and 2 Independents who caucused with the Democrats, giving the Democratic caucus the slightest 51–49 majority. Of the seats up for election in 2008, 23 were held by Republicans and 12 by Democrats. The Republicans, who openly conceded early on that they would not be able to regain the majority in this election, lost 8 seats. Democratic candidates defeated Republican incumbents in Alaska, New Hampshire, North Carolina, Oregon, and, after a lengthy recount process, Minnesota. Additionally, they won Republican-held open seats in Colorado, New Mexico, and Virginia.
Each major party has Hill committees that work to support its candidates for the House and Senate, chiefly by providing funds. On the Senate side, the committees are the Democratic Senatorial Campaign Committee (DSCC) and the National Republican Senatorial Committee (NRSC). In this cycle, the DSCC was more successful at fundraising. As of June 30, 2008, data from the Federal Election Commission showed the NRSC with $24.6 million on hand, as compared with the DSCC's $43 million. The NRSC chair, senator John Ensign, took the unusual step of chastising the Republican Senators who, like him, were not facing re-election, and who he thought should have done more to help raise money for their colleagues.
This election cycle was the second cycle in a row in which no seats switched from Democratic to Republican, and the first since 1990 in which the Democrats retained all their seats. In addition, this was the largest Democratic Senate gain since 1986, where they also won 8 seats. These elections marked the first time since 1964 in which a Democratic presidential candidate who won the White House had a Senate coattail effect. As of 2024, this is the last time Democrats won U.S. Senate seats in Alaska, Arkansas, Iowa, Louisiana, North Carolina, and South Dakota.
Along with 2 independents who caucus with them, Democrats held at least 58 seats as a result of the elections. The April 2009 party switch of Pennsylvania senator Arlen Specter from Republican to Democrat and the July 2009 resolution of the Minnesota election in favor of Democrat Al Franken increased the Democratic majority to 60–40 (briefly providing the Democrats a filibuster-proof majority, and thus they were able to hypothetically override any filibusters). Republicans gained a seat in a January 2010 special election in Massachusetts, thereby making the balance 59–41 before the start of the next election cycle.

## Results summary

| 57 | 2 | 41 |
| Democratic | Independent | Republican |
Summary of the 2008 United States Senate elections results
| Parties | Parties | | | | | | | | Total |
| Parties | Parties | Democratic | Republican | Independent | Libertarian | Independence | Green | Others | Total |
| Before these elections | Before these elections | 49 | 49 | 2 | — | — | — | — | 100 |
| Not up | Class 1 (2006→2012) | 22 | 8 | 2 | — | — | — | — | 31 |
| Not up | Class 3 (2004→2010) | 15 | 19 | — | — | — | — | — | 34 |
| Not up | Total | 37 | 26 | 2 | — | — | — | — | 65 |
| Up | Class 1 | — | 2 | — | — | — | — | — | 2 |
| Up | Class 2 | 12 | 21 | — | — | — | — | — | 33 |
| Up | Total | 12 | 23 | — | — | — | — | — | 35 |
| Incumbent retired | Total before | — | 5 | — | — | — | — | — | 5 |
| Incumbent retired | Held by same party | — | 2 | — | — | — | — | — | 2 |
| Incumbent retired | Replaced by other party | 3 Republicans replaced by 3 Democrats | 3 Republicans replaced by 3 Democrats | — | — | — | — | — | 3 |
| Incumbent retired | Result after | 3 | 2 | — | — | — | — | — | 5 |
| Incumbent ran | Total before | 12 | 18 | — | — | — | — | — | 30 |
| Incumbent ran | Won election | 12 | 13 | — | — | — | — | — | 25 |
| Incumbent ran | Lost election | 5 Republicans replaced by 5 Democrats | 5 Republicans replaced by 5 Democrats | — | — | — | — | — | 5 |
| Incumbent ran | Result after | 17 | 13 | — | — | — | — | — | 30 |
| Net gain/loss | Net gain/loss | 8 | 8 | — | — | — | — | — | 8 |
| Total elected | Total elected | 20 | 15 | — | — | — | — | — | 35 |
| Nation-wide vote | Votes | 33,650,061 | 28,863,067 | 176,752 | 798,154 | 450,702 | 427,427 | 496,124 | 64,862,287 |
| Nation-wide vote | Share | 51.88% | 44.50% | 0.27% | 1.23% | 0.69% | 0.66% | 0.76% | 100% |
| Result | Result | 57 | 41 | 2 | — | — | — | — | 100 |
* ↑ For the Georgia senate race, votes from the runoff election are counted.
Sources:
* Clerk of the U.S. House of Representatives
* U.S. Senate Popular Vote and FEC Total Receipts by Party, via TheGreenPapers.com
* "U.S. Senate (Full results)". CNN. July 1, 2009. Retrieved November 29, 2017.
* "The Green Papers 2008 U.S. Senate Popular Vote and FEC Total Receipts by Party". The Green Papers. Retrieved November 19, 2008.

## Change in composition
### Before the elections

| D$_1$ | D$_2$ | D$_3$ | D$_4$ | D$_5$ | D$_6$ | D$_7$ | D$_8$ | D$_9$ | D$_{10}$ |
| D$_{20}$ | D$_{19}$ | D$_{18}$ | D$_{17}$ | D$_{16}$ | D$_{15}$ | D$_{14}$ | D$_{13}$ | D$_{12}$ | D$_{11}$ |
| D$_{21}$ | D$_{22}$ | D$_{23}$ | D$_{24}$ | D$_{25}$ | D$_{26}$ | D$_{27}$ | D$_{28}$ | D$_{29}$ | D$_{30}$ |
| D$_{40}$ Ill. Ran | D$_{39}$ Del. Ran | D$_{38}$ Ark. Ran | D$_{37}$ | D$_{36}$ | D$_{35}$ | D$_{34}$ | D$_{33}$ | D$_{32}$ | D$_{31}$ |
| D$_{41}$ Iowa Ran | D$_{42}$ La. Ran | D$_{43}$ Mass. Ran | D$_{44}$ Mich. Ran | D$_{45}$ Mont. Ran | D$_{46}$ N.J. Ran | D$_{47}$ R.I. Ran | D$_{48}$ S.D. Ran | D$_{49}$ W.Va. Ran | I$_1$ |
| Majority (with Independents) ↑ | Majority (with Independents) ↑ | Majority (with Independents) ↑ | Majority (with Independents) ↑ | Majority (with Independents) ↑ | Majority (with Independents) ↑ | Majority (with Independents) ↑ | Majority (with Independents) ↑ | Majority (with Independents) ↑ | I$_2$ |
| R$_{41}$ N.C. Ran | R$_{42}$ Okla. Ran | R$_{43}$ Ore. Ran | R$_{44}$ S.C. Ran | R$_{45}$ Tenn. Ran | R$_{46}$ Texas Ran | R$_{47}$ Va. Retired | R$_{48}$ Wyo. (Reg) Ran | R$_{49}$ Wyo. (Sp) Ran | I$_2$ |
| R$_{40}$ N.M. Retired | R$_{39}$ N.H. Ran | R$_{38}$ Neb. Retired | R$_{37}$ Miss. (Sp) Ran | R$_{36}$ Miss. (Reg) Ran | R$_{35}$ Minn. Ran | R$_{34}$ Me. Ran | R$_{33}$ Ky. Ran | R$_{32}$ Kan. Ran | R$_{31}$ Idaho Retired |
| R$_{21}$ | R$_{22}$ | R$_{23}$ | R$_{24}$ | R$_{25}$ | R$_{26}$ | R$_{27}$ Ala. Ran | R$_{28}$ Alaska Ran | R$_{29}$ Colo. Retired | R$_{30}$ Ga. Ran |
| R$_{20}$ | R$_{19}$ | R$_{18}$ | R$_{17}$ | R$_{16}$ | R$_{15}$ | R$_{14}$ | R$_{13}$ | R$_{12}$ | R$_{11}$ |
| R$_1$ | R$_2$ | R$_3$ | R$_4$ | R$_5$ | R$_6$ | R$_7$ | R$_8$ | R$_9$ | R$_{10}$ |

### After the elections

| D$_1$ | D$_2$ | D$_3$ | D$_4$ | D$_5$ | D$_6$ | D$_7$ | D$_8$ | D$_9$ | D$_{10}$ |
| D$_{20}$ | D$_{19}$ | D$_{18}$ | D$_{17}$ | D$_{16}$ | D$_{15}$ | D$_{14}$ | D$_{13}$ | D$_{12}$ | D$_{11}$ |
| D$_{21}$ | D$_{22}$ | D$_{23}$ | D$_{24}$ | D$_{25}$ | D$_{26}$ | D$_{27}$ | D$_{28}$ | D$_{29}$ | D$_{30}$ |
| D$_{40}$ Ill. Re-elected | D$_{39}$ Del. Re-elected | D$_{38}$ Ark. Re-elected | D$_{37}$ | D$_{36}$ | D$_{35}$ | D$_{34}$ | D$_{33}$ | D$_{32}$ | D$_{31}$ |
| D$_{41}$ Iowa Re-elected | D$_{42}$ La. Re-elected | D$_{43}$ Mass. Re-elected | D$_{44}$ Mich. Re-elected | D$_{45}$ Mont. Re-elected | D$_{46}$ N.J. Re-elected | D$_{47}$ R.I. Re-elected | D$_{48}$ S.D. Re-elected | D$_{49}$ W.Va. Re-elected | D$_{50}$ Alaska Gain |
| Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | D$_{51}$ Colo. Gain |
| R$_{41}$ Wyo. (Sp) Elected | Vacant Minn. Disputed | I$_2$ | I$_1$ | D$_{56}$ Va. Gain | D$_{55}$ Ore. Gain | D$_{54}$ N.C. Gain | D$_{53}$ N.M. Gain | D$_{52}$ N.H. Gain | D$_{51}$ Colo. Gain |
| R$_{40}$ Wyo. (Reg) Re-elected | R$_{39}$ Texas Re-elected | R$_{38}$ Tenn. Re-elected | R$_{37}$ S.C. Re-elected | R$_{36}$ Okla. Re-elected | R$_{35}$ Neb. Hold | R$_{34}$ Miss. (Sp) Elected | R$_{33}$ Miss. (Reg) Re-elected | R$_{32}$ Me. Re-elected | R$_{31}$ Ky. Re-elected |
| R$_{21}$ | R$_{22}$ | R$_{23}$ | R$_{24}$ | R$_{25}$ | R$_{26}$ | R$_{27}$ Ala. Re-elected | R$_{28}$ Ga. Re-elected | R$_{29}$ Idaho Hold | R$_{30}$ Kan. Re-elected |
| R$_{20}$ | R$_{19}$ | R$_{18}$ | R$_{17}$ | R$_{16}$ | R$_{15}$ | R$_{14}$ | R$_{13}$ | R$_{12}$ | R$_{11}$ |
| R$_1$ | R$_2$ | R$_3$ | R$_4$ | R$_5$ | R$_6$ | R$_7$ | R$_8$ | R$_9$ | R$_{10}$ |

### Beginning of the first session

| D$_1$ | D$_2$ | D$_3$ | D$_4$ | D$_5$ | D$_6$ | D$_7$ | D$_8$ | D$_9$ | D$_{10}$ |
| D$_{20}$ | D$_{19}$ | D$_{18}$ | D$_{17}$ | D$_{16}$ | D$_{15}$ | D$_{14}$ | D$_{13}$ | D$_{12}$ | D$_{11}$ |
| D$_{21}$ | D$_{22}$ | D$_{23}$ | D$_{24}$ | D$_{25}$ | D$_{26}$ | D$_{27}$ | D$_{28}$ | D$_{29}$ | D$_{30}$ |
| D$_{40}$ | D$_{39}$ | D$_{38}$ | D$_{37}$ | D$_{36}$ | D$_{35}$ | D$_{34}$ | D$_{33}$ | D$_{32}$ | D$_{31}$ |
| D$_{41}$ | D$_{42}$ | D$_{43}$ | D$_{44}$ | D$_{45}$ | D$_{46}$ | D$_{47}$ | D$_{48}$ | D$_{49}$ | D$_{50}$ |
| Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | D$_{51}$ |
| I$_2$ | I$_1$ | D$_{58}$ Minn. Gain | D$_{57}$ Penn. Changed | D$_{56}$ | D$_{55}$ | D$_{54}$ | D$_{53}$ | D$_{52}$ | D$_{51}$ |
| R$_{40}$ | R$_{39}$ | R$_{38}$ | R$_{37}$ | R$_{36}$ | R$_{35}$ | R$_{34}$ | R$_{33}$ | R$_{32}$ | R$_{31}$ |
| R$_{21}$ | R$_{22}$ | R$_{23}$ | R$_{24}$ | R$_{25}$ | R$_{26}$ | R$_{27}$ | R$_{28}$ | R$_{29}$ | R$_{30}$ |
| R$_{20}$ | R$_{19}$ | R$_{18}$ | R$_{17}$ | R$_{16}$ | R$_{15}$ | R$_{14}$ | R$_{13}$ | R$_{12}$ | R$_{11}$ |
| R$_1$ | R$_2$ | R$_3$ | R$_4$ | R$_5$ | R$_6$ | R$_7$ | R$_8$ | R$_9$ | R$_{10}$ |
| Key: | D$_#$ Democratic I$_#$ Independent R$_#$ Republican |

## Race summary
### Special elections during the 110th Congress

In these special elections, the winner was seated during 2008 or before January 3, 2009, sorted by election date, then state, then class.
| State | Incumbent | Incumbent | Incumbent | Results | Candidates |
| State | Senator | Party | Electoral history | Results | Candidates |
| Mississippi (Class 1) | Roger Wicker | Republican | 2007 (appointed) | Interim appointee elected. | ▌Y Roger Wicker (Republican) 55.0% ▌Ronnie Musgrove (Democratic) 45.0% |
| Wyoming (Class 1) | John Barrasso | Republican | 2007 (appointed) | Interim appointee elected. | ▌Y John Barrasso (Republican) 73.4% ▌Nick Carter (Democratic) 26.5% |

### Elections leading to the next Congress

In these general elections, the winners were elected for the term beginning January 3, 2009; ordered by state.
All of the elections involved the Class 2 seats.
| State | Incumbent | Incumbent | Incumbent | Results | Candidates |
| State | Senator | Party | Electoral history | Results | Candidates |
| Alabama | Jeff Sessions | Republican | 1996 2002 | Incumbent re-elected. | ▌Y Jeff Sessions (Republican) 63.4% ▌Vivian Davis Figures (Democratic) 36.5% |
| Alaska | Ted Stevens | Republican | 1968 (appointed) 1970 (special) 1972 1978 1984 1990 1996 2002 | Incumbent lost re-election. Democratic gain. | ▌Y Mark Begich (Democratic) 47.8% ▌Ted Stevens (Republican) 46.6% ▌Bob Bird (Alaskan Independence) 4.2% Others ▌David Haase (Libertarian) 0.8% ▌Ted Gianoutsos (Independent) 0.4% |
| Arkansas | Mark Pryor | Democratic | 2002 | Incumbent re-elected. | ▌Y Mark Pryor (Democratic) 79.5% ▌Rebekah Kennedy (Green) 20.5% |
| Colorado | Wayne Allard | Republican | 1996 2002 | Incumbent retired. Democratic gain. | ▌Y Mark Udall (Democratic) 52.8% ▌Bob Schaffer (Republican) 42.5% ▌Doug Campbell (Constitution) 2.6% ▌Bob Kinsey (Green) 2.1% |
| Delaware | Joe Biden | Democratic | 1972 1978 1984 1990 1996 2002 | Incumbent re-elected. | ▌Y Joe Biden (Democratic) 64.7% ▌Christine O'Donnell (Republican) 35.3% |
| Georgia | Saxby Chambliss | Republican | 2002 | Incumbent re-elected. | First round: ▌Y Saxby Chambliss (Republican) 49.8% ▌Y Jim Martin (Democratic) 46.8% ▌Allen Buckley (Libertarian) 3.4% Runoff: ▌Y Saxby Chambliss (Republican) 57.5% ▌Jim Martin (Democratic) 42.5% |
| Idaho | Larry Craig | Republican | 1990 1996 2002 | Incumbent retired. Republican hold. | ▌Y Jim Risch (Republican) 57.7% ▌Larry LaRocco (Democratic) 34.1% ▌Rex Rammell (Independent) 5.4% Others ▌Kent Marmon (Libertarian) 1.5% ▌Pro-Life (Independent) 1.3% |
| Illinois | Dick Durbin | Democratic | 1996 2002 | Incumbent re-elected. | ▌Y Dick Durbin (Democratic) 67.8% ▌Steve Sauerberg (Republican) 28.5% Others ▌Kathy Cummings (Green) 2.2% ▌Larry Stafford (Libertarian) 0.9% ▌Chad Koppie (Constitution) 0.5% |
| Iowa | Tom Harkin | Democratic | 1984 1990 1996 2002 | Incumbent re-elected. | ▌Y Tom Harkin (Democratic) 62.7% ▌Christopher Reed (Republican) 37.3% |
| Kansas | Pat Roberts | Republican | 1996 2002 | Incumbent re-elected. | ▌Y Pat Roberts (Republican) 60.0% ▌Jim Slattery (Democratic) 36.4% Others ▌Randall Hodgkinson (Libertarian) 2.1% ▌Joseph Martin (Reform) 1.3% |
| Kentucky | Mitch McConnell | Republican | 1984 1990 1996 2002 | Incumbent re-elected. | ▌Y Mitch McConnell (Republican) 53.0% ▌Bruce Lunsford (Democratic) 47.0% |
| Louisiana | Mary Landrieu | Democratic | 1996 2002 | Incumbent re-elected. | ▌Y Mary Landrieu (Democratic) 52.1% ▌John Kennedy (Republican) 45.7% Others ▌Richard Fontanesi (Libertarian) 1.0% ▌Jay Patel (Independent) 0.7% ▌Robert Stewart (Independent) 0.5% |
| Maine | Susan Collins | Republican | 1996 2002 | Incumbent re-elected. | ▌Y Susan Collins (Republican) 61.3% ▌Tom Allen (Democratic) 38.6% |
| Massachusetts | John Kerry | Democratic | 1984 1990 1996 2002 | Incumbent re-elected. | ▌Y John Kerry (Democratic) 65.8% ▌Jeff Beatty (Republican) 31.0% ▌Robert Underwood (Libertarian) 3.2% |
| Michigan | Carl Levin | Democratic | 1978 1984 1990 1996 2002 | Incumbent re-elected. | ▌Y Carl Levin (Democratic) 62.7% ▌Jack Hoogendyk (Republican) 33.8% Others ▌Scott Boman (Libertarian) 1.6% ▌Harley Mikkelson (Green) 0.9% ▌Michael Nikitin (Constitution) 0.6% ▌Doug Dern (Natural Law) 0.4% |
| Minnesota | Norm Coleman | Republican | 2002 | Incumbent lost re-election. Democratic (DFL) gain. Winner delayed term until July 7, 2009, due to election dispute. | ▌Y Al Franken (DFL) 41.99% ▌Norm Coleman (Republican) 41.98% ▌Dean Barkley (IPM) 15.15% Others ▌Charles Aldrich (Libertarian) 0.48% ▌James Niemackl (Constitution) 0.31% ▌Write-ins 0.08% |
| Mississippi | Thad Cochran | Republican | 1978 1984 1990 1996 2002 | Incumbent re-elected. | ▌Y Thad Cochran (Republican) 61.4% ▌Erik R. Fleming (Democratic) 38.6% |
| Montana | Max Baucus | Democratic | 1978 1984 1990 1996 2002 | Incumbent re-elected. | ▌Y Max Baucus (Democratic) 72.9% ▌Bob Kelleher (Republican) 27.1% |
| Nebraska | Chuck Hagel | Republican | 1996 2002 | Incumbent retired. Republican hold. | ▌Y Mike Johanns (Republican) 57.5% ▌Scott Kleeb (Democratic) 40.1% Others ▌Kelly Rosberg (Nebraska) 1.4% ▌Steve Larrick (Green) 1.0% |
| New Hampshire | John E. Sununu | Republican | 2002 | Incumbent lost re-election. Democratic gain. | ▌Y Jeanne Shaheen (Democratic) 51.7% ▌John E. Sununu (Republican) 45.2% ▌Ken Blevens (Libertarian) 3.1% |
| New Jersey | Frank Lautenberg | Democratic | 1982 1982 (appointed) 1988 1994 2000 (retired) 2002 | Incumbent re-elected. | ▌Y Frank Lautenberg (Democratic) 56.0% ▌Dick Zimmer (Republican) 42.0% Others ▌Jason Scheurer (Libertarian) 0.5% ▌J. M. Carter (Independent) 0.5% ▌Daryl Mikell Brooks (Independent) 0.5% ▌Jeffrey Boss (Independent) 0.3% ▌Sara Lobman (Socialist Workers) 0.3% |
| New Mexico | Pete Domenici | Republican | 1972 1978 1984 1990 1996 2002 | Incumbent retired. Democratic gain. | ▌Y Tom Udall (Democratic) 61.3% ▌Steve Pearce (Republican) 38.7% |
| North Carolina | Elizabeth Dole | Republican | 2002 | Incumbent lost re-election. Democratic gain. | ▌Y Kay Hagan (Democratic) 52.7% ▌Elizabeth Dole (Republican) 44.2% ▌Chris Cole (Libertarian) 3.1% |
| Oklahoma | Jim Inhofe | Republican | 1994 (special) 1996 2002 | Incumbent re-elected. | ▌Y Jim Inhofe (Republican) 56.7% ▌Andrew Rice (Democratic) 39.2% ▌Stephen Wallace (Independent) 4.1% |
| Oregon | Gordon H. Smith | Republican | 1996 2002 | Incumbent lost re-election. Democratic gain. | ▌Y Jeff Merkley (Democratic) 48.9% ▌Gordon H. Smith (Republican) 45.6% ▌Dave Brownlow (Constitution) 5.2% |
| Rhode Island | Jack Reed | Democratic | 1996 2002 | Incumbent re-elected. | ▌Y Jack Reed (Democratic) 73.4% ▌Robert Tingle (Republican) 26.6% |
| South Carolina | Lindsey Graham | Republican | 2002 | Incumbent re-elected. | ▌Y Lindsey Graham (Republican) 57.5% ▌Bob Conley (Democratic) 42.3% |
| South Dakota | Tim Johnson | Democratic | 1996 2002 | Incumbent re-elected. | ▌Y Tim Johnson (Democratic) 62.5% ▌Joel Dykstra (Republican) 37.5% |
| Tennessee | Lamar Alexander | Republican | 2002 | Incumbent re-elected. | ▌Y Lamar Alexander (Republican) 65.1% ▌Bob Tuke (Democratic) 31.6% Others ▌Edward Buck (Independent) 1.3% ▌Christopher Fenner (Independent) 0.5% ▌Daniel Lewis (Libertarian) 0.4% ▌Chris Lugo (Green) 0.4% ▌Ed Lawhorn (Independent) 0.4% ▌David Gatchell (Independent) 0.3% |
| Texas | John Cornyn | Republican | 2002 2002 (appointed) | Incumbent re-elected. | ▌Y John Cornyn (Republican) 54.8% ▌Rick Noriega (Democratic) 42.8% ▌Yvonne Adams Schick (Libertarian) 2.3% |
| Virginia | John Warner | Republican | 1978 1984 1990 1996 2002 | Incumbent retired. Democratic gain. | ▌Y Mark Warner (Democratic) 65.0% ▌Jim Gilmore (Republican) 33.7% Others ▌Bill Redpath (Libertarian) 0.6% ▌Gail Parker (Independent Green) 0.6% |
| West Virginia | Jay Rockefeller | Democratic | 1984 1990 1996 2002 | Incumbent re-elected. | ▌Y Jay Rockefeller (Democratic) 63.7% ▌Jay Wolfe (Republican) 36.3% |
| Wyoming | Mike Enzi | Republican | 1996 2002 | Incumbent re-elected. | ▌Y Mike Enzi (Republican) 75.6% ▌Chris Rothfuss (Democratic) 24.3% |

### Special elections during the next Congress

There were no special elections in 2009.

## Closest races

In nine races the margin of victory was under 10%. However, Georgia proceeded to a runoff election where the Republican candidate won by over 10%.
| District | Winner | Margin |
| Minnesota | Democratic (flip) | 0.01% |
| Alaska | Democratic (flip) | 1.3% |
| Oregon | Democratic (flip) | 3.6% |
| Georgia general | Republican | 3.0% |
| Kentucky | Republican | 5.9% |
| New Hampshire | Democratic (flip) | 6.3% |
| Louisiana | Democratic | 6.4% |
| North Carolina | Democratic (flip) | 8.5% |
| Mississippi special | Republican | 9.9% |
South Dakota was the tipping point state, decided by a margin of 25.0%.

## Final pre-election predictions

Several sites and individuals published predictions of competitive seats. These predictions looked at factors such as the strength of the incumbent (if the incumbent was running for re-election) and the other candidates, and the state's partisan lean (reflected in part by the state's Cook Partisan Voting Index rating). The predictions assigned ratings to each seat, indicating the predicted advantage that a party had in winning that seat. Most election predictors used:
* "tossup": no advantage
* "tilt" (used by some predictors): advantage that is not quite as strong as "lean"
* "lean": slight advantage
* "likely": significant, but surmountable, advantage
* "safe" or "solid": near-certain chance of victory
| Constituency | Incumbent | Incumbent | 2008 election ratings | 2008 election ratings | 2008 election ratings | 2008 election ratings | 2008 election ratings |
| State | Senator | Last election | Cook | CQ Politics | Rothenberg | RCP | Result |
| Alabama | Jeff Sessions | 58.6% R | Safe R | Safe R | Safe R | Safe R | Sessions (63.4%) |
| Alaska | Ted Stevens | 78.2% R | Lean D (flip) | Lean D (flip) | Lean D (flip) | Lean D (flip) | Begich (47.8%)(flip) |
| Arkansas | Mark Pryor | 53.9% D | Safe D | Safe D | Safe D | Safe D | Pryor (79.5%) |
| Colorado | Wayne Allard (retiring) | 50.7% R | Lean D (flip) | Likely D (flip) | Likely D (flip) | Likely D (flip) | M. Udall (52.8%) (flip) |
| Delaware | Joe Biden | 58.2% D | Safe D | Safe D | Safe D | Safe D | Biden (64.7%) |
| Georgia | Saxby Chambliss | 52.8% R | Tossup | Tossup | Lean R | Tossup | Chambliss (57.4%) |
| Idaho | Larry Craig (retiring) | 65.2% R | Safe R | Safe R | Safe R | Safe R | Risch (57.7%) |
| Illinois | Dick Durbin | 60.3% D | Safe D | Safe D | Safe D | Safe D | Durbin (67.8%) |
| Iowa | Tom Harkin | 54.2% D | Safe D | Safe D | Safe D | Safe D | Harkin (62.7%) |
| Kansas | Pat Roberts | 82.5% R | Safe R | Likely R | Safe R | Safe R | Roberts (60.1%) |
| Kentucky | Mitch McConnell | 64.7% R | Lean R | Lean R | Lean R | Tossup | McConnell (53.0%) |
| Louisiana | Mary Landrieu | 51.7% D | Lean D | Lean D | Lean D | Lean D | Landrieu (52.1%) |
| Maine | Susan Collins | 58.4% R | Likely R | Lean R | Likely R | Likely R | Collins (61.3%) |
| Massachusetts | John Kerry | 80.0% D | Safe D | Safe D | Safe D | Safe D | Kerry (65.9%) |
| Michigan | Carl Levin | 60.6% D | Safe D | Safe D | Safe D | Safe D | Levin (62.7%) |
| Minnesota | Norm Coleman | 49.5% R | Tossup | Tossup | Tossup | Tossup | Franken (42.0%)(flip) |
| Mississippi (regular) | Thad Cochran | 84.6% R | Safe R | Safe R | Safe R | Safe R | Cochran (61.4%) |
| Mississippi (special) | Roger Wicker | Appointed (2007) | Tossup | Lean R | Lean R | Lean R | Wicker (55.0%) |
| Montana | Max Baucus | 62.7% D | Safe D | Safe D | Safe D | Safe D | Baucus (72.9%) |
| Nebraska | Chuck Hagel (retiring) | 82.8% R | Likely R | Likely R | Safe R | Likely R | Johanns (57.5%) |
| New Hampshire | John Sununu | 50.8% R | Tossup | Lean D (flip) | Likely D (flip) | Lean D (flip) | Shaheen (51.6%)(flip) |
| New Jersey | Frank Lautenberg | 53.9% D | Safe D | Likely D | Safe D | Likely D | Lautenberg (56.0%) |
| New Mexico | Pete Domenici (retiring) | 65.0% R | Lean D (flip) | Likely D (flip) | Likely D (flip) | Likely D (flip) | T. Udall (61.3%)(flip) |
| North Carolina | Elizabeth Dole | 53.5% R | Tossup | Lean D (flip) | Lean D (flip) | Tossup | Hagan (52.6%)(flip) |
| Oklahoma | Jim Inhofe | 57.3% R | Likely R | Likely R | Safe R | Safe R | Inhofe (56.7%) |
| Oregon | Gordon Smith | 56.2% R | Tossup | Tossup | Lean D (flip) | Tossup | Merkley (48.9%)(flip) |
| Rhode Island | Jack Reed | 78.4% D | Safe D | Safe D | Safe D | Safe D | Reed (73.4%) |
| South Carolina | Lindsey Graham | 54.4% R | Safe R | Safe R | Safe R | Safe R | Graham (57.5%) |
| South Dakota | Tim Johnson | 49.6% D | Likely D | Safe D | Safe D | Safe D | Johnson (62.5%) |
| Tennessee | Lamar Alexander | 54.3% R | Safe R | Likely R | Safe R | Safe R | Alexander (65.1%) |
| Texas | John Cornyn | 55.3% R | Safe R | Likely R | Safe R | Safe R | Cornyn (54.8%) |
| Virginia | John Warner (retiring) | 82.6% R | Likely D (flip) | Safe D (flip) | Likely D (flip) | Safe D (flip) | M. Warner (65.0%)(flip) |
| West Virginia | Jay Rockefeller | 63.1% D | Safe D | Safe D | Safe D | Safe D | Rockefeller (63.7%) |
| Wyoming (regular) | Mike Enzi | 73.0% R | Safe R | Safe R | Safe R | Safe R | Enzi (75.6%) |
| Wyoming (special) | John Barrasso | Appointed (2007) | Safe R | Safe R | Safe R | Safe R | Barrasso (73.4%) |

## Gains and losses
### Retirements

Five Republicans retired rather than seek re-election.
| State | Senator | Replaced by |
| Colorado | Wayne Allard | Mark Udall |
| Idaho | Larry Craig | Jim Risch |
| Nebraska | Chuck Hagel | Mike Johanns |
| New Mexico | Pete Domenici | Tom Udall |
| Virginia | John Warner | Mark Warner |

### Defeats

Five Republicans sought re-election but lost in the general election.
| State | Senator | Replaced by |
| Alaska | Ted Stevens | Mark Begich |
| Minnesota | Norm Coleman | Al Franken |
| New Hampshire | John E. Sununu | Jeanne Shaheen |
| North Carolina | Elizabeth Dole | Kay Hagan |
| Oregon | Gordon H. Smith | Jeff Merkley |

### Post-election changes

Four Democrats resigned and were replaced by Democrats. One Republican was switched to Democrat on April 28, 2009. Two other Democrats died on August 25, 2009, and June 28, 2010, respectively, while another Republican resigned on September 9, 2009.
| State | Senator | Replaced by |
| Colorado (Class 3) | Ken Salazar | Michael Bennet |
| Delaware (Class 2) | Joe Biden | Ted Kaufman |
| Florida (Class 3) | Mel Martínez | George LeMieux |
| Illinois (Class 3) | Barack Obama | Roland Burris |
| Massachusetts (Class 1) | Ted Kennedy | Paul G. Kirk |
| New York (Class 1) | Hillary Clinton | Kirsten Gillibrand |
| Pennsylvania (Class 3) | Arlen Specter | Arlen Specter |
| West Virginia (Class 1) | Robert Byrd | Carte Goodwin |

## Alabama

Alabama senator Jeff Sessions sought re-election to a third term. Johnny Swanson announced his candidacy in March 2006 for the Democratic nomination.
Despite voting heavily for Bush in 2004, Alabama still had a strong Democratic presence; Democrats controlled majorities of both chambers in the state legislature. Commissioner of Agriculture and Industries Ron Sparks appeared to be preparing for a run, but on June 12, 2007, Sparks announced that he would not seek the Senate seat, in order to avoid a primary battle with state senator Vivian Davis Figures. Figures has won elections in the Republican-leaning Mobile area. In the Democratic primary, Figures won the nomination and face Sessions in November.
Not on the ballot, but running a write-in campaign, was Darryl W. Perry, the 2004 Libertarian Party nominee for Pennsylvania State Treasurer and 2007 candidate for Mayor of Birmingham, Alabama. Perry was endorsed by Alabama Statesmen, Boston Tea Party, and Christians for Life and Liberty.
Sessions defeated Figures, taking 63% of the vote to Figures's 37%
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Jeff Sessions (incumbent) | 199,690 | 92.27% |
| | Republican | Earl Mack Gavin | 16,718 | 7.73% |
| Total votes | Total votes | Total votes | 216,408 | 100.00% |
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vivian Davis Figures | 112,074 | 63.72% |
| | Democratic | Johnny Swanson | 38,757 | 22.03% |
| | Democratic | Mark Townsend | 25,058 | 14.25% |
| Total votes | Total votes | Total votes | 175,889 | 100.00% |
Alabama general :
| Party | Party | Candidate | Votes | % |
| | Republican | Jeff Sessions (Incumbent) | 1,305,383 | 63.36% |
| | Democratic | Vivian Davis Figures | 752,391 | 36.52% |
| | Write-In | Write-ins | 2,417 | 0.12% |
| Invalid or blank votes | Invalid or blank votes | Invalid or blank votes | | |
| Total votes | Total votes | Total votes | 2,060,191 | 100.00% |
| Turnout | Turnout | Turnout | | N/A |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Alaska

Alaska ADL senatorial primary, 2008 :
| Party | Party | Candidate | Votes | % |
| | Democratic | Mark Begich | 63,747 | 84.12% |
| | Democratic | Ray Metcalfe | 5,480 | 7.23% |
| | Independence | Bob Bird | 4,216 | 5.56% |
| | Libertarian | Fredrick Haase | 1,375 | 1.81% |
| | Democratic | Frank Vondersaar | 965 | 1.27% |
| Total votes | Total votes | Total votes | 75,783 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Ted Stevens (incumbent) | 66,900 | 63.52% |
| | Republican | David Cuddy | 28,364 | 26.93% |
| | Republican | Vic Vickers | 6,102 | 5.79% |
| | Republican | Michael Corey | 1,496 | 1.42% |
| | Republican | Roderic Sikma | 1,133 | 1.08% |
| | Republican | Rich Wanda | 732 | 0.69% |
| | Republican | Gerald Heikes | 599 | 0.57% |
| Total votes | Total votes | Total votes | 105,326 | 100.00% |
Alaska general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Mark Begich | 151,767 | 47.77% | +37.26% |
| | Republican | Ted Stevens (Incumbent) | 147,814 | 46.52% | −31.65% |
| | Independence | Bob Bird | 13,197 | 4.15% | +1.22% |
| | Libertarian | Fredrick Haase | 2,483 | 0.78% | −0.25% |
| | Independent | Ted Gianoutsos | 1,385 | 0.44% | |
| | Write-ins | | 1,077 | 0.34% | |
| Majority | Majority | Majority | 3,953 | 1.24% | −66.42% |
| Turnout | Turnout | Turnout | 317,723 | | |
| | Democratic gain from Republican | Democratic gain from Republican | Swing | | |
Dispelling rumors that he would retire due to advanced age (he was 84 years old on election day) and ongoing federal investigations into his conduct, senator Ted Stevens filed papers for re-election for an eighth term.
An ex-oil company executive, Bill Allen, paid for part of the renovation costs on Stevens's personal residence. The FBI investigated the remodeling of Stevens home by Veco Corp., which is part of a broader corruption investigation involving Stevens's son, former State Senate President Ben Stevens. Two former Veco executives have pleaded guilty to paying the younger Stevens $242,000 in bribes. On July 30, 2007, the IRS and FBI raided Stevens's home in Alaska. On September 14, 2007, former Veco CEO Bill Allen testified at the trial of former State House Speaker Pete Kott that Veco paid people working to double the size of Stevens's home.
On July 29, 2008, a federal grand jury indicted Stevens on seven felony counts for making false statements, and on October 26, a jury found Stevens guilty on all charges.
The Democratic candidate was Anchorage Mayor Mark Begich, the son of popular former Democratic Representative Nick Begich. Begich announced his candidacy for the Senate seat on April 22, 2008.
On October 19, 2007, the AP reported that despite the allegations and FBI probe, several veteran GOP Senators—including Orrin Hatch (R-UT), Kay Bailey Hutchison (R-TX), and Kit Bond (R-MO)—donated enough money to Stevens's re-election campaign to make it one of Stevens's most successful fund raising quarters ever.
Stevens's conviction on seven felony counts of corruption damaged his re-election bid, coming just over a week before the election, though Stevens appealed the conviction. Nevertheless, Stevens was narrowly ahead in the vote count after election day, with only about two-thirds of all votes counted. It only became clear Begich had prevailed when early votes, absentee ballots, and questioned ballots were counted.
On November 18, the race was called for Begich, who won with 47.8% to Stevens's 46.5%. Stevens was the most senior U.S. Senator to ever lose re-election, defeating Warren Magnuson's 1980 record. As of 2023, Stevens still holds this record.
On April 1, 2009, U.S. Attorney General Eric Holder, citing serious prosecutorial misconduct during the trial, decided to drop all charges against Stevens—an action that vacated his conviction.

## Arkansas

Arkansas general :
| Party | Party | Candidate | Votes | % |
| | Democratic | Mark Pryor (Incumbent) | 804,678 | 79.53% |
| | Green | Rebekah Kennedy | 207,076 | 20.47% |
| Total votes | Total votes | Total votes | 1,011,754 | 100.00% |
| Invalid or blank votes | Invalid or blank votes | Invalid or blank votes | 75,586 | n/a |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |
Despite being a first-term senator in a state George W. Bush won twice, Democrat Mark Pryor faced no opposition from Republicans in his re-election bid. Although Bush carried the state twice, Arkansas Democrats swept the seven state races held in the 2006 general election. Pryor is the son of longtime U.S. senator and former Arkansas Governor David Pryor. It was rumored that Lt. Governor Bill Halter would challenge Pryor in the primary, but Halter declined to file as a candidate. Rebekah Kennedy of the Green Party was Pryor's only opposition. Pryor won on election day, with 79.53% of the vote. Kennedy took 20.47%.

## Colorado

Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Mark Udall | 194,227 | 100.00% |
| Total votes | Total votes | Total votes | 194,227 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Bob Schaffer | 239,212 | 100.00% |
| Total votes | Total votes | Total votes | 239,212 | 100.00% |
Colorado general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Mark Udall | 1,230,994 | 52.80% | +7.03% |
| | Republican | Bob Schaffer | 990,755 | 42.49% | −8.20% |
| | Constitution | Douglas Campbell | 59,733 | 2.56% | +1.04% |
| | Green | Bob Kinsey | 50,004 | 2.14% | |
| | Write-ins | | 135 | 0.01% | |
| Majority | Majority | Majority | 240,239 | 10.30% | +5.38% |
| Turnout | Turnout | Turnout | 2,331,621 | | |
| | Democratic gain from Republican | Democratic gain from Republican | Swing | | |
On January 15, 2007, incumbent senator Wayne Allard (R) announced he would not seek re-election, honoring his pledge to serve no more than two terms.
Former Representative Bob Schaffer of Fort Collins was the Republican nominee. Former Denver Broncos quarterback John Elway was rumored to be considering a run, but declined to do so. Other possible Republican candidates included former Congressman Scott McInnis and Colorado Attorney General John Suthers.
The Democratic nominee was 2nd district Congressman Mark Udall of Boulder who announced on January 15, 2007, that he would seek the seat and did not draw significant primary opposition.
Other candidates included Bob Kinsey of Denver as the Green Party nominee, Douglas "Dayhorse" Campbell as the American Constitution Party's nominee, and Independent candidate Buddy Moore, unaffiliated any party.
On Election Day, Udall defeated Schaffer 53% to 43%.

## Delaware

Delaware general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Joe Biden (Incumbent) | 257,539 | 64.69% | +6.47% |
| | Republican | Christine O'Donnell | 140,595 | 35.31% | −5.49% |
| Majority | Majority | Majority | 116,944 | 29.37% | +11.96% |
| Turnout | Turnout | Turnout | 398,134 | | |
| | Democratic hold | Democratic hold | Swing | | |
On August 23, 2008, the Democratic nominee for president, Barack Obama, announced that Biden would be joining him on the ticket as the vice presidential nominee. Delaware law allowed Biden to run for vice president and senator at the same time, so he would have kept the Senate seat if the presidential ticket had lost. In 1988 and 2000, the Democratic vice presidential nominees Lloyd Bentsen and Joe Lieberman, ran similarly for their seat in Texas and Connecticut, respectively. On November 4, 2008, Barack Obama won the presidential election, making Biden the next VP. Biden vacated his senate seat shortly after the election, allowing for the Governor of Delaware to appoint a successor. There was speculation as to whether the outgoing Governor, Ruth Ann Minner, or the incoming Governor-elect Jack Markell would make the appointment, and if Biden's son, Delaware Attorney General Beau Biden would receive the appointment. On November 24, 2008, Governor Minner appointed Biden's longtime Chief of Staff Ted Kaufman to fill the seat. Kaufman subsequently announced that he would not seek election to a full term in 2010, effectively making him a caretaker. Biden's Republican opponent in the Senate race, conservative political commentator Christine O'Donnell, tried to make an issue of Biden's dual campaigns, claiming that serving his constituents is not important to him.
Biden was re-elected with 65% of the vote, or 257,484 votes. O'Donnell received 140,584 votes (35% of the vote).

## Georgia

2008 Georgia U.S. Senate Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Saxby Chambliss | 392,902 | 100.0% |
| Turnout | Turnout | Turnout | 392,928 | 100.0% |
2008 Georgia U.S. Senate Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Vernon Jones | 199,026 | 40.4% |
| | Democratic | Jim Martin | 169,635 | 34.4% |
| | Democratic | Dale Cardwell | 79,181 | 16.1% |
| | Democratic | Rand Knight | 25,667 | 5.2% |
| | Democratic | Josh Lanier | 19,717 | 4.0% |
| Total votes | Total votes | Total votes | 493,226 | 100.0% |
2008 Georgia U.S. Senate Democratic primary election runoff :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jim Martin | 191,061 | 59.9% | +25.5% |
| | Democratic | Vernon Jones | 127,993 | 40.1% | −0.3% |
| Total votes | Total votes | Total votes | 319,054 | 100.0% | |
Georgia general :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Saxby Chambliss (Incumbent) | 1,867,097 | 49.8% | −3.0% |
| | Democratic | Jim Martin | 1,757,393 | 46.8% | +0.9% |
| | Libertarian | Allen Buckley | 127,923 | 3.4% | +2.1% |
| | Socialist Workers | Eleanor Garcia (write-in) | 43 | 0.0% | n/a |
| | Independent | William Salomone Jr. (write-in) | 29 | 0.0% | n/a |
| Majority | Majority | Majority | 109,704 | 2.92% | |
| Turnout | Turnout | Turnout | 3,752,577 | | |
Runoff election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Saxby Chambliss (Incumbent) | 1,228,033 | 57.4% | +7.6% |
| | Democratic | Jim Martin | 909,923 | 42.6% | −4.2% |
| Majority | Majority | Majority | 318,110 | 14.8% | |
| Turnout | Turnout | Turnout | 2,137,956 | | |
| | Republican hold | Republican hold | Swing | | |
In the 2008 election, first-term incumbent Republican senator Saxby Chambliss was opposed primarily by Democrat Jim Martin, as well as third-party candidates, including Libertarian Allen Buckley and Eleanor Garcia of the Socialist Workers Party.
Martin, current Georgia Commissioner of Human Resources, former member of the Georgia General Assembly, Vietnam War veteran, and 2006 candidate for lieutenant governor, secured the Democratic nomination after defeating DeKalb County CEO Vernon Jones by a 59% to 41% margin in the August 5 run-off election.
In December 2007, Chambliss had an approval rating of 53% and a disapproval rating of 34% according to Strategic Vision, a Republican polling firm. For most of the campaign, Chambliss maintained a comfortable lead in most polls. However, in the weeks leading up to the 2008 general election, polls showed the race tightening, reflecting a general nationwide trend.
On November 4, 2008, Chambliss received 49.8% of the vote, with Martin about 3% behind and Buckley receiving 3% of the vote. However, Georgia law stated that if no candidate receives a simple majority of the popular vote, then the election will be decided in a run-off. On December 2, 2008, Chambliss won the run-off with 57% of vote to Martin's 43%.

## Idaho

Democratic Primary results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Larry LaRocco | 29,023 | 72.35% |
| | Democratic | David J. Archuleta | 11,074 | 27.60% |
| | Democratic | Write-ins | 20 | 0.05% |
| Total votes | Total votes | Total votes | 40,117 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Jim Risch | 80,743 | 65.34% |
| | Republican | Scott Syme | 16,660 | 13.48% |
| | Republican | Richard Phenneger | 6,532 | 5.29% |
| | Republican | Neal Thompson | 5,375 | 4.35% |
| | Republican | Fred M. Adams | 4,987 | 4.04% |
| | Republican | Bill Hunter | 4,280 | 3.46% |
| | Republican | Brian E. Hefner | 2,915 | 2.36% |
| | Republican | Hal James Styles Jr. | 2,082 | 1.68% |
| Total votes | Total votes | Total votes | 123,574 | 100.00% |
Idaho general :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Jim Risch | 371,744 | 57.65% | −7.51% |
| | Democratic | Larry LaRocco | 219,903 | 34.11% | +1.56% |
| | Independent | Rex Rammell | 34,510 | 5.35% | |
| | Libertarian | Kent Marmon | 9,958 | 1.54% | −0.75% |
| | Independent | Pro-Life | 8,662 | 1.35% | |
| | Write-ins | | 3 | 0.00% | |
| Majority | Majority | Majority | 151,841 | 23.55% | −9.06% |
| Turnout | Turnout | Turnout | 644,780 | | |
| | Republican hold | Republican hold | Swing | | |
On September 1, 2007, senator Larry Craig announced his intent to resign from the Senate effective September 30, 2007. The announcement followed by just six days the disclosure that he had pleaded guilty on August 1, 2007, to a reduced misdemeanor charge arising out of his arrest on June 11 at the Minneapolis airport for soliciting sex with a man in the restroom. Craig found almost no support among Republicans in his home state or Washington. On October 4, 2007, senator Craig announced he will not seek re-election, but would remain in office until the end of his term.
Lieutenant Governor Jim Risch was the Republican candidate; U.S. Army veteran and former congressman Larry LaRocco was the Democratic candidate. Risch and LaRocco ran against each other in the 2006 Lieutenant Governor race, which Risch won by a wide margin. Libertarian Kent Marmon also ran. The last Democratic senator from Idaho was Frank Church, who was defeated in the Republican landslide of 1980 after serving four terms.
Risch won the election with approximately 58% of the vote.

## Illinois

Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Dick Durbin (Incumbent) | 1,653,833 | 100.00% |
| Total votes | Total votes | Total votes | 1,653,833 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Steve Sauerberg | 395,199 | 55.62% |
| | Republican | Andy Martin | 240,548 | 33.85% |
| | Republican | Mike Psak | 74,829 | 10.53% |
| Total votes | Total votes | Total votes | 710,576 | 100.00% |
Illinois general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Dick Durbin (Incumbent) | 3,615,844 | 67.84% | +7.51% |
| | Republican | Steve Sauerberg | 1,520,621 | 28.53% | −9.49% |
| | Green | Kathy Cummings | 119,135 | 2.24% | 0.00% |
| | Libertarian | Larry A. Stafford | 50,224 | 0.94% | −0.70% |
| | Constitution | Chad N. Koppie | 24,059 | 0.45% | 0.00% |
| Majority | Majority | Majority | 2,095,223 | 39.31% | +17.00% |
| Turnout | Turnout | Turnout | 5,329,884 | | |
| | Democratic hold | Democratic hold | Swing | | |
Senate Majority Whip Richard Durbin remained favored in Illinois. He sought to be re-elected in a state that has steadily become more Democratic since 1992. CQpolitics.com rated the contest as "safe Democrat".
Physician Steve Sauerberg of La Grange won the February 5 Republican primary. Kathy Cummings, a retired special education teacher was nominated via convention by the Green Party. Chad Koppie, a retired airline pilot and vice-chairman of the Illinois Center Right Coalition, was the nominee of the Constitution Party.
Durbin won with 68% of the vote. Sauerberg had 29%.

## Iowa

Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Tom Harkin (Incumbent) | 90,785 | 98.83% |
| | Democratic | Write-ins | 1,074 | 1.17% |
| Total votes | Total votes | Total votes | 91,859 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Christopher Reed | 24,964 | 35.32% |
| | Republican | George Eichhorn | 24,390 | 34.52% |
| | Republican | Steve Rathje | 21,062 | 29.80% |
| | Republican | Write-ins | 256 | 0.36% |
| Total votes | Total votes | Total votes | 70,672 | 100.00% |
Iowa general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Tom Harkin (Incumbent) | 941,665 | 62.66% | +8.48% |
| | Republican | Christopher Reed | 560,006 | 37.26% | −6.52% |
| | Write-ins | | 1,247 | 0.08% | |
| Majority | Majority | Majority | 381,659 | 25.39% | +15.00% |
| Turnout | Turnout | Turnout | 1,502,918 | | |
| | Democratic hold | Democratic hold | Swing | | |
In a state that had been trending to the Democratic party recently, senator Tom Harkin faced the Republican nominee, small business owner Christopher Reed, whom he defeated with 63% of the vote to Reed's 37%.

## Kansas

Republican Party primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Pat Roberts (Incumbent) | 214,911 | 100.00% |
| Total votes | Total votes | Total votes | 214,911 | 100.00% |
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jim Slattery | 68,106 | 68.93% |
| | Democratic | Lee Jones | 30,699 | 31.07% |
| Total votes | Total votes | Total votes | 98,805 | 100.00% |
Kansas general :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Pat Roberts (Incumbent) | 727,121 | 60.06% | −22.46% |
| | Democratic | Jim Slattery | 441,399 | 36.46% | |
| | Libertarian | Randall Hodgkinson | 25,727 | 2.12% | −6.98% |
| | Reform | Joseph L. Martin | 16,443 | 1.36% | −7.02% |
| Majority | Majority | Majority | 285,722 | 23.60% | −49.82% |
| Turnout | Turnout | Turnout | 1,210,690 | | |
| | Republican hold | Republican hold | Swing | | |
Senator Pat Roberts sought re-election to a third term. Although Kansas has not elected a Democrat to the Senate since 1932, former Democratic Congressman and army veteran Jim Slattery was nominated to run against Roberts. Pat Roberts currently has an approval rating of 56%.
Roberts was re-elected with 60% to Slattery's 36%.

## Kentucky

Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Mitch McConnell (incumbent) | 168,127 | 86.09% |
| | Republican | Daniel Essek | 27,170 | 13.91% |
| Total votes | Total votes | Total votes | 195,297 | 100.00% |
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bruce Lunsford | 316,992 | 51.15% |
| | Democratic | Greg Fischer | 209,827 | 33.85% |
| | Democratic | David L. Williams | 34,363 | 5.54% |
| | Democratic | Michael Cassaro | 17,340 | 2.80% |
| | Democratic | Kenneth Stepp | 13,451 | 2.17% |
| | Democratic | David Wylie | 7,528 | 1.21% |
| | Democratic | James E. Rice | 2,365 | 3.28% |
| Total votes | Total votes | Total votes | 619,904 | 100.00% |
Kentucky general :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Mitch McConnell (incumbent) | 953,816 | 52.97% | −11.7% |
| | Democratic | Bruce Lunsford | 847,005 | 47.03% | +11.7% |
| Turnout | Turnout | Turnout | 1,800,821 | 62.00% | +19.2% |
| | Republican hold | Republican hold | Swing | | |
Democrats made Senate Minority Leader, four-term senator Mitch McConnell of Kentucky a target due to his leadership of Senate Republicans and his ties to President Bush, as well as his mediocre approval rating in the state, which was below 50%.
Businessman and U.S. Army veteran Bruce Lunsford, who lost the 2007 Democratic gubernatorial primary to Governor Steve Beshear, was the Democratic nominee.
Once thought to be secure in his re-election, McConnell's lead had shrunk dramatically thanks to the financial crisis and polling showed the race tightening between him and Lunsford. Nevertheless, McConnell was re-elected by a margin of 53% to 47%.

## Louisiana

General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Mary Landrieu (Incumbent) | 988,298 | 52.11% | +0.41% |
| | Republican | John Neely Kennedy | 867,177 | 45.72% | −2.58% |
| | Libertarian | Richard Fontanesi | 18,590 | 0.98% | n/a |
| | Independent | Jay Patel | 13,729 | 0.72% | n/a |
| | Independent | Robert Stewart | 8,780 | 0.46% | n/a |
| Majority | Majority | Majority | 121,121 | 6.39% | +2.99% |
| Turnout | Turnout | Turnout | 1,896,574 | 100.0% | |
| | Democratic hold | Democratic hold | Swing | | |
Incumbent Mary Landrieu was elected in 1996 following a recount and was narrowly re-elected in 2002 in a runoff election. Since those elections, Democrats have had to endure the loss of some reliable voters because Hurricane Katrina dispersed many African-Americans from New Orleans, although the vast majority still live within Louisiana. The state has become more Republican over the past 12 years. Louisiana elected David Vitter in 2004, the state's first Republican senator since Reconstruction, as well as Republican Bobby Jindal as the first Indian-American Governor in the country's history in 2007. Louisiana's electoral votes easily went to George W. Bush in 2000 and 2004.
On August 27, 2007, state Treasurer John Neely Kennedy announced he was switching parties from Democrat to Republican. On November 29, after being personally recruited by Vitter and former Bush administration official Karl Rove, Kennedy announced plans to challenge Landrieu in 2008.
In the end, Landrieu was re-elected with 52% of the vote, Kennedy having 46%.

## Maine

2008 Maine U.S. Senate Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Tom Allen | 69,932 | 85.6% |
| | Democratic | Tom Ledue | 11,795 | 14.4% |
| Turnout | Turnout | Turnout | 81,727 | |
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Susan Collins (incumbent) | 444,300 | 61.33% | +2.9% |
| | Democratic | Tom Allen | 279,510 | 38.58% | −3.0% |
| | | write-ins | 620 | 0.09% | n/a |
| Majority | Majority | Majority | 164,790 | | |
| Turnout | Turnout | Turnout | 724,430 | | |
| | Republican hold | Republican hold | Swing | | |
In Maine, Susan Collins sought a third term in the Senate. She has maintained a high approval rating, and also in her favor is the landslide re-election of Maine's senior Senator, Olympia Snowe, who had the largest margin of victory of any GOP Senate candidate - besides the largely unopposed Richard Lugar (R-IN) - in the 2006 election cycle. Collins was re-elected with 58% of the vote in 2002 over State Sen. Chellie Pingree. Fellow senator Joe Lieberman, citing his status as an independent, endorsed Collins in her 2008 re-election bid.
On May 8, 2007, Rep. Tom Allen (ME-1) announced his candidacy on his website Archived May 10, 2007, at the Wayback Machine. He had already expressed interest in running and had been building the apparatus necessary to wage a Senate campaign.
Collins won on election day with 61% of the vote, compared to 39% for Allen.

## Massachusetts

Democratic primary in Massachusetts :
| Party | Party | Candidate | Votes | % |
| | Democratic | John Kerry (incumbent) | 335,923 | 68.92% |
| | Democratic | Edward O'Reilly | 151,473 | 31.08% |
| Turnout | Turnout | Turnout | 487,396 | |
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | John Kerry (Incumbent) | 1,959,843 | 65.82% | −14.2% |
| | Republican | Jeff Beatty | 922,727 | 30.99% | +30.99% |
| | Libertarian | Robert J. Underwood | 94,727 | 3.18% | −15.1% |
| Majority | Majority | Majority | 1,037,116 | | |
| Turnout | Turnout | Turnout | 2,977,631 | | |
| | Democratic hold | Democratic hold | Swing | | |
Incumbent John Kerry sought another Senate term in Massachusetts. Republican author and conservative activist Jerome Corsi, known for his public criticism of Kerry, had stated that he would run for the seat in 2008 but later changed his mind. Jim Ogonowski, a retired Air Force pilot who was closely defeated by now-Representative Niki Tsongas in a 2007 special election, was running against Kerry. but failed to obtain the required candidacy signatures. The Republican challenger turned out to be Jeff Beatty, an ex-Army Delta Force officer who garnered 30% of the vote in a challenge to Democratic Congressman Bill Delahunt in 2006. Kerry was challenged by defense attorney Edward O'Reilly for the Democratic nomination, winning 69% of the vote to O'Reilly's 31%.
Kerry won with 66% of the vote to Beatty's 31%. Libertarian Robert J. Underwood had 3%.

## Michigan

Michigan general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Carl Levin (Incumbent) | 3,038,386 | 62.7% | +2.1% |
| | Republican | Jack Hoogendyk | 1,641,070 | 33.8% | −4.1% |
| | Libertarian | Scotty Boman | 76,347 | 1.6% | n/a |
| | Green | Harley Mikkelson | 43,440 | 0.9% | +0.1% |
| | U.S. Taxpayers | Michael Nikitin | 30,827 | 0.6% | n/a |
| | Natural Law | Doug Dern | 18,550 | 0.4% | +0.1% |
| Majority | Majority | Majority | 1,397,316 | | |
| Turnout | Turnout | Turnout | 4,848,620 | | |
| | Democratic hold | Democratic hold | Swing | | |
With the Democratic Party takeover of Capitol Hill in the 2006 midterm elections, senator Carl Levin had become one of the most powerful people in Washington as chairman of the Senate Armed Services Committee. He was expected to easily win re-election.
Challenging Levin were Republican State Representative Jack Hoogendyk, Green candidate Harley G. Mikkelson, US Taxpayers' candidate Mike Nikitin, Libertarian professor Scotty Boman, and Natural Law's candidate Doug Dern.
Levin won re-election with 63% of the vote, to Hoogendyk's 34%.

## Minnesota

Democratic–Farmer–Labor primary :
| Party | Party | Candidate | Votes | % |
| | Democratic (DFL) | Al Franken | 164,136 | 65.34% |
| | Democratic (DFL) | Priscilla Lord Faris | 74,655 | 29.72% |
| | Democratic (DFL) | Dick Franson | 3,923 | 1.56% |
| | Democratic (DFL) | Bob Larson | 3,152 | 1.25% |
| | Democratic (DFL) | Rob Fitzgerald | 3,095 | 1.23% |
| | Democratic (DFL) | Ole Savior | 1,227 | 0.49% |
| | Democratic (DFL) | Alve Erickson | 1,017 | 0.40% |
| Turnout | Turnout | Turnout | 251,205 | |
Independence primary :
| Party | Party | Candidate | Votes | % |
| | Independence | Dean Barkley | 6,678 | 58.88% |
| | Independence | Jack Uldrich | 1,405 | 12.39% |
| | Independence | Stephen Williams | 800 | 7.05% |
| | Independence | Kurt Michael Anderson | 761 | 6.71% |
| | Independence | Doug Williams | 639 | 5.63% |
| | Independence | Darryl Stanton | 618 | 5.45% |
| | Independence | Bill Dahn | 440 | 3.88% |
| Turnout | Turnout | Turnout | 11,341 | |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Norm Coleman (Incumbent) | 130,973 | 91.32% |
| | Republican | Jack Shepard | 12,456 | 8.68% |
| Turnout | Turnout | Turnout | 143,429 | |
2007 year-end reports filed with the Federal Election Commission showed that Al Franken had raised $7.04 million through December 31, 2007, while Norm Coleman had raised $6.24 million. Year-end cash on hand was $6.04 million for Coleman and $3.10 million for Franken.
General election (Results certified November 18) :
| Party | Party | Candidate | Votes | % |
| | Republican | Norm Coleman (Incumbent) | 1,211,590 | 41.988% |
| | Democratic (DFL) | Al Franken | 1,211,375 | 41.981% |
| | Independence | Dean Barkley | 437,404 | 15.19% |
| | Libertarian | Charles Aldrich | 13,916 | 0.48% |
| | Constitution | James Niemackl | 8,905 | 0.31% |
| | Write-ins | | 2,365 | 0.08% |
| Plurality | Plurality | Plurality | 215 | 0.007% |
| Turnout | Turnout | Turnout | 2,885,555 | |
Note: The ±% column reflects the change in total number of votes won by each party from the previous election. Additionally, votes cast for Paul Wellstone in the 2002 election are not factored into the DFL's total from that year.
General election (Results certified January 5, 2009) :
| Party | Party | Candidate | Votes | % |
| | Democratic (DFL) | Al Franken | 1,212,431 | 41.991% |
| | Republican | Norm Coleman (Incumbent) | 1,212,206 | 41.984% |
| | Independence | Dean Barkley | 437,505 | 15.15% |
| | Libertarian | Charles Aldrich | 13,923 | 0.48% |
| | Constitution | James Niemackl | 8,907 | 0.31% |
| | Write-ins | | 2,365 | 0.08% |
| Plurality | Plurality | Plurality | 225 | 0.007% |
| Turnout | Turnout | Turnout | 2,887,337 | |
General election (Results certified after election contest) :
| Party | Party | Candidate | Votes | % |
| | Democratic (DFL) | Al Franken | 1,212,629 | 41.994% |
| | Republican | Norm Coleman (Incumbent) | 1,212,317 | 41.983% |
| | Independence | Dean Barkley | 437,505 | 15.151% |
| | Libertarian | Charles Aldrich | 13,923 | 0.48% |
| | Constitution | James Niemackl | 8,907 | 0.31% |
| | Write-ins | | 2,365 | 0.08% |
| Plurality | Plurality | Plurality | 312 | 0.011% |
| Turnout | Turnout | Turnout | 2,887,646 | |
| | Democratic (DFL) gain from Republican | Democratic (DFL) gain from Republican | Democratic (DFL) gain from Republican | Democratic (DFL) gain from Republican |
The 2008 U.S. Senate election in Minnesota featured first-term Republican incumbent senator Norm Coleman, Democrat Al Franken, a comedian and radio personality, and former U.S. senator Dean Barkley, a member of the Independence Party of Minnesota.
A December 2007 poll showed Coleman's approval rating among Minnesota voters at 53%. The seat was heavily targeted by the Democratic Senatorial Campaign Committee because of Minnesota's Democratic leanings and recent Democratic gains in national and statewide elections. These factors, coupled with a national political climate favorable to Democrats, made the Minnesota Senate race one of the most competitive and closely watched of the cycle.
Franken announced his candidacy on February 14, 2007, more than 20 months before the election. Jack Nelson-Pallmeyer, a professor at the University of St. Thomas (St. Paul, Minnesota), joined the race in October 2007. Attorney Mike Ciresi, an unsuccessful candidate in the 2000 Democratic U.S. Senate primary, was considered a serious candidate, but withdrew from the race on March 10, 2008, clearing the path for Franken to secure the party's nomination.
Barkley, who had briefly been appointed Senator after the death of Paul Wellstone in 2002, ran under the banner of the Independence Party, the largest third party in Minnesota. He was included in most of the debates and ultimately received 15% of the vote in the general election, a strong showing for a third-party candidate. It is not clear whether Barkley detracted more votes from Coleman or Franken.
Polls over the course of the campaign indicated that the race was very competitive, with many polls showing Franken and Coleman virtually tied or within the margin of error, as well as several polls showing each candidate with a significant lead at one point or another. The presence of a serious third-party candidate further complicated matters.
On November 4, 2008, Coleman received 1,211,590 votes to Franken's 1,211,375 votes, a margin of 215 votes, far less than 0.1%, thereby triggering an automatic recount. Barkley received 437,404 votes, about 15% of total votes cast.
On January 3, 2009, with the recount apparently completed, Franken had an unofficial lead of 225 votes, but former senator Coleman's attorneys contested the official results in the courts. During the recount process, Minnesota was represented by only one senator, Amy Klobuchar.
On April 13, 2009, a three-judge panel ruled that Al Franken received the most votes in Minnesota's 2008 Senate race and ruled against Coleman's claims on all counts. Coleman appealed this decision. On June 30, 2009, the Minnesota Supreme Court ruled unanimously that Al Franken received the most votes, and Norm Coleman conceded defeat after the ruling, allowing Al Franken to be Senator-elect of Minnesota. Franken was sworn in as Minnesota's junior senator on July 7.

## Mississippi
### Mississippi (regular)

Incumbent Republican Thad Cochran announced that he would seek re-election for a sixth term. Cochran, who has not faced serious opposition since he was re-elected in 1984, faced Democratic state Representative Erik R. Fleming, whom he defeated with 61% of the vote.
Mississippi general :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Thad Cochran (Incumbent) | 766,111 | 61.44% | −23.2% |
| | Democratic | Erik Fleming | 480,915 | 38.56% | n/a |
| Majority | Majority | Majority | 285,196 | | |
| Turnout | Turnout | Turnout | 1,247,026 | | |
| | Republican hold | Republican hold | Swing | | |

### Mississippi (special)

Roger Wicker, formerly the representative of Mississippi's 1st congressional district, was appointed by Governor Haley Barbour on December 31, 2007, to fill the vacancy caused by the December 18 resignation of Trent Lott. It had been speculated that Lott wished to resign before a new lobbying reform law, effective the first day of 2008, took effect; having resigned before the end of 2007, Lott may become a lobbyist in 2009 instead of 2010. Controversy arose when Barbour called for the special election to be held on the same day as the general election. As a result, Mississippi's Attorney General Jim Hood challenged Barbour in court, claiming that the special election needed to be held within 100 days of Lott's resignation, as per state law. Initially, a Mississippi Circuit Court judge sided with Hood, ruling that the election take place on or before March 19, 2008. However, Barbour filed an appeal to the Mississippi Supreme Court, which overturned the earlier ruling and set the special election for November 4, 2008.
Democratic former Governor Ronnie Musgrove challenged Wicker. Another Democrat, former Congressman Ronnie Shows, also filed to run, but he withdrew in February 2008 and endorsed Musgrove. Wicker beat Musgrove 55% to 45%.
2008 Mississippi U.S. Senate special election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Roger Wicker (incumbent) | 683,409 | 54.96% | −8.6% |
| | Democratic | Ronnie Musgrove | 560,064 | 45.04% | +9.9% |
| Majority | Majority | Majority | 123,345 | | |
| Turnout | Turnout | Turnout | 1,243,473 | | |
| | Republican hold | Republican hold | Swing | | |

## Montana

Senator Max Baucus was a popular Democrat in Montana, representing a state that has long been fairly Republican but also receptive to Democrats in state and local elections. President Bush won Montana by more than 20 points in both 2000 and 2004, but Montana also had a popular Democratic governor, Brian Schweitzer, and a newly elected Democratic junior senator, Jon Tester. Baucus was not expected to face a significant challenge from the 85-year-old Republican nominee, Bob Kelleher, who surprised observers by winning the June 3 Republican primary despite supporting a number of positions that put him to the political left of Baucus, such as nationalization of the American oil and gas industry.
Baucus easily won re-election, taking 73% of the vote, with Kelleher taking 27%.
Democratic Party primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Max Baucus (Incumbent) | 165,050 | 100.00% |
| Total votes | Total votes | Total votes | 165,050 | 100.00% |
Republican Party primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Bob Kelleher | 26,936 | 36.32% |
| | Republican | Michael Lange | 17,044 | 22.98% |
| | Republican | Kirk Bushman | 15,507 | 20.91% |
| | Republican | Patty Lovaas | 7,632 | 10.29% |
| | Republican | Anton Pearson | 4,257 | 5.74% |
| | Republican | Shay Joshua Garnett | 2,788 | 3.76% |
| Total votes | Total votes | Total votes | 74,164 | 100.00% |
Montana general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Max Baucus (incumbent) | 348,289 | 72.92% | +10.18% |
| | Republican | Bob Kelleher | 129,369 | 27.08% | −4.65% |
| Majority | Majority | Majority | 218,920 | 45.84% | +14.84% |
| Turnout | Turnout | Turnout | 477,658 | | |
| | Democratic hold | Democratic hold | Swing | | |

## Nebraska

In Nebraska, incumbent Republican Chuck Hagel chose to retire rather than run for a third term.
Former Governor Mike Johanns, who recently resigned as Agriculture Secretary, was the Republican nominee, having defeated opponent Pat Flynn 87–13 in the primary. Scott Kleeb, 2006 candidate for Nebraska's 3rd congressional district, defeated businessman Tony Raimondo, a former Republican, by a wide margin in the Democratic primary.
Nebraska state Green Party Co-Chairman Steve Larrick was also a candidate, as was Kelly Rosberg of the Nebraska Party.
Johanns won, taking 58% of the vote, with Kleeb taking 40%.
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Mike Johanns | 112,191 | 78.61% |
| | Republican | Pat Flynn | 31,560 | 21.12% |
| Total votes | Total votes | Total votes | 143,751 | 100.00% |
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Scott Kleeb | 65,582 | 68.37% |
| | Democratic | Tony Raimondo | 24,141 | 25.17% |
| | Democratic | James Bryan Wilson | 3,224 | 3.36% |
| | Democratic | Larry Marvin | 2,672 | 2.80% |
| Total votes | Total votes | Total votes | 95,919 | 100.00% |
Green Party primary :
| Party | Party | Candidate | Votes | % |
| | Green | Steve Larrick | 123 | 100.00% |
| Total votes | Total votes | Total votes | 123 | 100.00% |
Nebraska Party primary :
| Party | Party | Candidate | Votes | % |
| | Nebraska | Barry Richards | 209 | 100.00% |
| Total votes | Total votes | Total votes | 209 | 100.00% |
General election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Mike Johanns | 455,854 | 57.5% | −25.2% |
| | Democratic | Scott Kleeb | 317,456 | 40.1% | +25.5% |
| | Nebraska | Kelly Renee Rosberg | 11,438 | 1.4% | n/a |
| | Green | Steve Larrick | 7,763 | 1.0% | n/a |
| Majority | Majority | Majority | 138,398 | | |
| Turnout | Turnout | Turnout | 792,511 | | |
| | Republican hold | Republican hold | Swing | | |

## New Hampshire

Incumbent Republican John E. Sununu represented the swing state of New Hampshire. The state traditionally leaned Republican, but John Kerry from neighboring Massachusetts narrowly won the state in the 2004 Presidential election. New Hampshire also saw major Democratic gains in the 2006 elections, when Democrats took both of the previously Republican-held House seats, the gubernatorial race with a record vote share of 74%, and majorities in the State House and Senate, giving them concurrent control of both bodies for the first time since 1874. However, New Hampshire had not elected a Democratic United States senator since 1975.
Sununu's 2002 opponent, former Governor Jeanne Shaheen, decided to run and was generally considered to be a very formidable challenger. Three consecutive monthly Rasmussen Reports poll showed Shaheen defeating Sununu by 49% to 41%. Prior to Shaheen's entry, Portsmouth Mayor Steve Marchand, Katrina Swett, wife of former Democratic congressman Richard Swett, and former astronaut Jay Buckey had announced that they were running for the Democratic nomination. After Shaheen's entry, however, all three withdrew and endorsed the former governor.
On election day, Shaheen defeated Sununu, 52% to 45%.
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jeanne Shaheen | 43,968 | 88.5% |
| | Democratic | Raymond Stebbins | 5,281 | 10.6% |
| | | write-ins | 407 | 0.8% |
| Turnout | Turnout | Turnout | 49,656 | |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | John Sununu (Incumbent) | 60,852 | 88.7% |
| | Republican | Tom Alciere | 7,084 | 10.3% |
| | | write-ins | 685 | 1.0% |
| Turnout | Turnout | Turnout | 68,621 | |
General election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jeanne Shaheen | 358,438 | 51.6% | +5.2% |
| | Republican | John Sununu (Incumbent) | 314,403 | 45.3% | −5.5% |
| | Libertarian | Ken Blevens | 21,516 | 3.1% | +0.9% |
| Majority | Majority | Majority | 44,035 | | |
| Turnout | Turnout | Turnout | 694,357 | | |
| | Democratic gain from Republican | Democratic gain from Republican | Swing | | |

## New Jersey

Incumbent Democrat Frank Lautenberg sought re-election in 2008, though he was 84. In the Primary, Lautenberg soundly defeated Representative Rob Andrews (NJ-1) by a margin of 62% to 32%. In November 2006, the senator had the lowest approval rating of any Democrat running for re-election in 2008 (with 39% approving and 45% disapproving), with his approval standing only at 42% as of September 2007 with voters saying he does not deserve re-election 46%-36%. The Republican nominee was former Congressman and 1996 senatorial candidate Dick Zimmer.
Sara Lobman of the Socialist Workers Party and Independent Anthony Fisher were also declared candidates. Furthermore, in the wake of the financial crisis, Carl Peter Klapper entered the race as a write-in candidate.
Lautenberg won re-election, winning 56%-42%.
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Frank Lautenberg (incumbent) | 203,012 | 58.9% |
| | Democratic | Rob Andrews | 121,777 | 35.3% |
| | Democratic | Donald Cresitello | 19,743 | 5.7% |
| Turnout | Turnout | Turnout | 344,532 | |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Dick Zimmer | 84,663 | 45.8% |
| | Republican | Joseph Pennacchio | 74,546 | 40.3% |
| | Republican | Murray Sabrin | 25,576 | 13.8% |
| Turnout | Turnout | Turnout | 184,785 | |
General election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Frank Lautenberg (incumbent) | 1,951,218 | 56.0% | +2.1% |
| | Republican | Dick Zimmer | 1,461,025 | 42.0% | −2.0% |
| | Independent | Daryl Mikell Brooks | 20,920 | 1.0% | n/a |
| | Libertarian | Jason Scheurer | 18,810 | 0.5% | n/a |
| | Independent | J.M. Carter | 15,935 | 0.5% | n/a |
| | Independent | Jeff Boss | 10,345 | 0.3% | n/a |
| | Socialist Workers | Sara Lobman | 9,187 | 0.3% | n/a |
| Majority | Majority | Majority | 490,193 | | |
| Turnout | Turnout | Turnout | 3,482,445 | | |
| | Democratic hold | Democratic hold | Swing | | |

## New Mexico

While senator Pete Domenici had declared that he would seek re-election in New Mexico, he changed his mind and announced on October 4, 2007, that he was retiring at the end of his current term due to a degenerative brain disorder. Domenici normally would have been expected to win re-election easily, having won his current term with the support of two out of three New Mexico voters; however, he was to be investigated by the Senate Ethics Committee for his role in firing U.S. Attorney David Iglesias. Domenici's role in the developing scandal had reduced the probability he would have been re-elected, and a SurveyUSA poll showed his approval ratings at 41%, with 54% disapproving. The potential scandal may have also contributed to his decision to leave the Senate.
Tom Udall, the popular Representative from New Mexico's 3rd District, was the Democratic nominee. The Republican nominee was Rep. Steve Pearce, who represented the more conservative southern part of the state.
When asked whether the Republicans were abandoning their hopes of holding onto Domenici's seat, senator John Ensign, the chairman of the National Republican Senatorial Committee, responded that "You don't waste money on races that don't need it or you can't win."
Udall won the election with 61% of the vote, with Pearce taking 39%.
Democratic Party primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Tom Udall | 141,629 | 100.00% |
| Total votes | Total votes | Total votes | 141,629 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Steve Pearce | 57,953 | 51.29% |
| | Republican | Heather Wilson | 55,039 | 48.71% |
| Total votes | Total votes | Total votes | 112,992 | 100.00% |
New Mexico general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Tom Udall | 505,128 | 61.33% | +26.37% |
| | Republican | Steve Pearce | 318,522 | 38.67% | −26.37% |
| Majority | Majority | Majority | 186,606 | 22.66% | −7.43% |
| Turnout | Turnout | Turnout | 823,650 | | |
| | Democratic gain from Republican | Democratic gain from Republican | Swing | | |

## North Carolina

In North Carolina, there had been rumors that senator Elizabeth Dole would retire from the Senate and run for governor, but she said in 2006 that she intended to run for re-election. There was early speculation that North Carolina Governor Mike Easley might be pressured into running against her but this did not come to pass. The Democratic nominee was state senator Kay Hagan, who defeated Jim Neal and Dustin Lassiter in the Democratic primary. A Rasmussen poll released May 11, 2008, showed Hagan leading Dole by a statistically insignificant margin, 48% - 47%, suggesting a competitive race. Hagan's poll numbers continued to best Dole's, however, and Hagan defeated Dole by a wider than expected margin of 53% to 44%.
Democratic Primary election :
| Party | Party | Candidate | Votes | % |
| | Democratic | Kay Hagan | 801,920 | 60.1% |
| | Democratic | Jim Neal | 239,623 | 18.0% |
| | Democratic | Marcus W. Williams | 170,970 | 12.8% |
| | Democratic | Duskin Lassiter | 62,136 | 4.6% |
| | Democratic | Howard Staley | 60,403 | 4.5% |
| Turnout | Turnout | Turnout | 1,335,052 | |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Elizabeth Dole (Incumbent) | 460,665 | 90.0% |
| | Republican | Pete DiLauro | 51,406 | 10.0% |
| Turnout | Turnout | Turnout | 512,071 | |
North Carolina general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Kay Hagan | 2,249,311 | 52.65% | +7.7% |
| | Republican | Elizabeth Dole (Incumbent) | 1,887,510 | 44.18% | −9.4% |
| | Libertarian | Chris Cole | 133,430 | 3.17% | +2.1% |
| | Other | Write-Ins | 1,719 | 0.0% | 0.0% |
| Majority | Majority | Majority | 361,801 | | |
| Turnout | Turnout | Turnout | 4,271,970 | | |
| | Democratic gain from Republican | Democratic gain from Republican | Swing | | |

## Oklahoma

In Oklahoma, senator Jim Inhofe announced that he would seek a third full term. A September 2007 poll put Inhofe's approval rating at 47%, with 41% disapproving of his performance. Inhofe's opponent was State senator Andrew Rice. Inhofe was re-elected, 57% to 39%.
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Andrew Rice | 113,795 | 59.65% |
| | Democratic | Jim Rogers | 76,981 | 40.35% |
| Total votes | Total votes | Total votes | 190,776 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Jim Inhofe (Incumbent) | 116,371 | 84.18% |
| | Republican | Evelyn R. Rogers | 10,770 | 7.79% |
| | Republican | Ted Ryals | 7,306 | 5.28% |
| | Republican | Dennis Lopez | 3,800 | 2.75% |
| Total votes | Total votes | Total votes | 138,247 | 100.00% |
Oklahoma general :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Jim Inhofe (Incumbent) | 763,375 | 56.68% | −0.62% |
| | Democratic | Andrew Rice | 527,736 | 39.18% | +2.87% |
| | Independent | Stephen Wallace | 55,708 | 4.14% | |
| Majority | Majority | Majority | 235,639 | 17.50% | −3.50% |
| Turnout | Turnout | Turnout | 1,346,819 | | |
| | Republican hold | Republican hold | Swing | | |

## Oregon

Senator Gordon Smith of Oregon ran for a third term. He defeated ophthalmologist Gordon Leitch in the May 20 Republican primary. Smith faced Democratic Oregon House of Representatives Speaker Jeff Merkley in the November general election. Merkley beat longtime Democratic activist Steve Novick and three other candidates in a hotly contested primary.
In a July 16, 2008, poll, Merkley overtook Smith for the first time 43% to 41%.
On November 6, 2008, Jeff Merkley was projected the winner of the contest, with 48.9% to Smith's 45.6%. Gordon Smith formally conceded soon afterward.
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jeff Merkley | 246,482 | 44.82% |
| | Democratic | Steve Novick | 230,889 | 41.98% |
| | Democratic | Candy Neville | 38,367 | 6.98% |
| | Democratic | Roger S. Obrist | 12,647 | 2.30% |
| | Democratic | Pavel Goberman | 12,056 | 2.19% |
| | Democratic | David Loera | 6,127 | 1.11% |
| | Democratic | Write-ins | 3,398 | 0.62% |
| Total votes | Total votes | Total votes | 549,966 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Gordon Smith (Incumbent) | 296,330 | 85.41% |
| | Republican | Gordon Leitch | 48,560 | 14.00% |
| | Republican | Write-ins | 2,068 | 0.69% |
| Total votes | Total votes | Total votes | 309,943 | 100.00% |
Oregon general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jeff Merkley | 864,392 | 48.90% | +9.30% |
| | Republican | Gordon H. Smith (Incumbent) | 805,159 | 45.55% | −10.66% |
| | Constitution | David Brownlow | 92,565 | 5.24% | +3.52% |
| | Write-ins | | 5,388 | 0.30% | |
| Majority | Majority | Majority | 59,233 | 3.35% | −13.25% |
| Turnout | Turnout | Turnout | 1,767,504 | | |
| | Democratic gain from Republican | Democratic gain from Republican | Swing | | |

## Rhode Island

In Rhode Island, Democratic senator Jack Reed had an approval rating of 66% in November 2006. National Journal has declared that "Reed is probably the safest incumbent of the 2008 cycle". Reed's opponent was Robert Tingle, a pit manager at the Foxwoods Resort Casino in Connecticut, whom Reed defeated in his re-election campaign in 2002.
Reed won the election, with 73% of the vote.
2008 Rhode Island U.S. Senate Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jack Reed (incumbent) | 48,038 | 86.8% |
| | Democratic | Christopher Young | 7,277 | 13.2% |
| Turnout | Turnout | Turnout | 55,315 | |
2008 Rhode Island U.S. Senate general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jack Reed (incumbent) | 320,644 | 73.4% | −5.0% |
| | Republican | Bob Tingle | 116,174 | 26.6% | +5.0% |
| Majority | Majority | Majority | 204,470 | | |
| Turnout | Turnout | Turnout | 436,818 | | |
| | Democratic hold | Democratic hold | Swing | | |

## South Carolina

Senator Lindsey Graham, as a popular Republican incumbent in strongly conservative South Carolina, had been considered unlikely to be vulnerable to a Democratic challenge. Graham's support for a compromise immigration bill, however, drew an angry response from many South Carolina conservatives, who recruited Buddy Witherspoon, a former South Carolina Republican Party leader, to challenge Graham for the nomination. Graham easily bested Witherspoon in the June 10 primary.
First-time candidate Bob Conley, an airline pilot, was the Democratic nominee. Conley, whose victory in the Democratic primary over Michael Cone was a surprise, is a former Republican who supported Ron Paul in 2008 and campaigned as the more conservative candidate on some issues, notably illegal immigration and the bailout of Wall Street.
The South Carolina Working Families Party had also nominated Michael Cone. South Carolina's election law allows for electoral fusion. This was the first time the party nominated a candidate for statewide office. However, because he lost the Democratic primary, Cone was not listed on the ballot under the state's sore loser law.
Graham easily won re-election with 58% of the vote to Conley's 42%.
2008 South Carolina U.S. Senate Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bob Conley | 74,125 | 50.3% |
| | Democratic | Michael Cone | 73,127 | 49.7% |
| Turnout | Turnout | Turnout | 147,252 | |
2008 South Carolina U.S. Senate Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Lindsey Graham (incumbent) | 187,736 | 66.8% |
| | Republican | Buddy Witherspoon | 93,125 | 33.2% |
| Turnout | Turnout | Turnout | 280,861 | |
South Carolina general :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Lindsey Graham (incumbent) | 1,076,534 | 57.52% | +3.1% |
| | Democratic | Bob Conley | 790,621 | 42.25% | −1.9% |
| | Write-ins | | 4,276 | 0.23% | +0.1% |
| Majority | Majority | Majority | 285,913 | | |
| Turnout | Turnout | Turnout | 1,871,431 | | |
| | Republican hold | Republican hold | Swing | | |

## South Dakota

In South Dakota, senator Tim Johnson's seat was considered a top GOP target in 2008, considering Johnson's narrow 524-vote victory in 2002 over then-Representative and current U.S. senator John Thune, as well as his recent health problems. Johnson underwent surgery in December 2006 for a cerebral arteriovenous malformation and was discharged from the hospital on April 30, 2007. On October 19, 2007, Johnson formally announced that he was seeking re-election. According to a November 2006 SurveyUSA poll, Johnson had an approval rating of 70%, with just 26% disapproving of his performance, making him an early favorite despite the state's Republican lean.
Republicans were unsuccessful in persuading Governor Mike Rounds and former Lieutenant Governor Steve Kirby to run. State Representative Joel Dykstra announced his candidacy on July 5, 2007. Other Republicans included Charles Lyonel Gonyo and Sam Kephart. Dykstra won the Republican primary on June 3.
Johnson was re-elected, with 62.5% to Dykstra's 37.5%. This seat was the tipping point state in the 2008 senate elections.
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Joel Dykstra | 34,598 | 65.74% |
| | Republican | Sam Kephart | 13,047 | 24.79% |
| | Republican | Charles Gonyo | 4,983 | 9.47% |
| Total votes | Total votes | Total votes | 52,628 | 100.00% |
South Dakota general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Tim Johnson (Incumbent) | 237,889 | 62.49% | +12.87% |
| | Republican | Joel Dykstra | 142,784 | 37.51% | −11.96% |
| Majority | Majority | Majority | 95,105 | 24.98% | +24.83% |
| Turnout | Turnout | Turnout | 380,673 | | |
| | Democratic hold | Democratic hold | Swing | | |

## Tennessee

Former Governor and U.S. Secretary of Education Lamar Alexander was elected in 2002 to succeed retiring senator Fred Thompson. He has announced he will seek a second term in 2008. He was unopposed in the Republican primary.
Former Chairman of the Tennessee Democratic Party Bob Tuke was the Democratic nominee, defeating Businessman Gary Davis 30% to 23%. Knox County Clerk Mike Padgett received 20% of the vote.
2006 Green Party Senate nominee Chris Lugo originally announced as a Democrat but dropped out of the Democratic race before the filing deadline. He filed as an independent and was subsequently named as the Green Party nominee Edward Buck was also in the race.
Daniel Lewis ran as a Libertarian candidate for the United States Senate. He was certified March 3, 2008, by the Tennessee Division of Elections as having achieved ballot access for the November 4, 2008, election as a candidate for United States Senate. The Libertarian Party of Tennessee officially selected Daniel Lewis as their candidate for United States Senate on Saturday March 8, 2008, at their annual convention held in Nashville, Tennessee. Mr. Lewis was serving as the chairman of the Libertarian Party of Metropolitan Nashville and Davidson County. He ran for the Tennessee House in 2004.
Also reported to be in the race are David "None of the Above" Gatchell a ballot activist & frequent candidate and Emory "Bo" Heyward, a software company employee, conservative activist & 2006 candidate.
Alexander won the election with 65% of the vote.
Democratic Party primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bob Tuke | 59,050 | 32.21% |
| | Democratic | Gary G. Davis | 39,119 | 21.34% |
| | Democratic | Mike Padgett | 33,471 | 18.26% |
| | Democratic | Mark E. Clayton | 32,309 | 17.62% |
| | Democratic | Kenneth Eaton | 14,702 | 8.02% |
| | Democratic | Leonard D. Ladner | 4,697 | 2.55% |
| Total votes | Total votes | Total votes | 183,348 | 100.00% |
Republican Party primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Lamar Alexander (Incumbent) | 244,222 | 100.00% |
| Total votes | Total votes | Total votes | 244,222 | 100.00% |
Tennessee general :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Lamar Alexander (Incumbent) | 1,579,477 | 65.14% | +10.87% |
| | Democratic | Bob Tuke | 767,236 | 31.64% | −12.69% |
| | Independent | Edward L. Buck | 31,631 | 1.30% | N/A |
| | Independent | Christopher G. Fenner | 11,073 | 0.46% | N/A |
| | Independent | Daniel Towers Lewis | 9,367 | 0.39% | N/A |
| | Independent | Chris Lugo | 9,170 | 0.38% | N/A |
| | Independent | Ed Lawhorn | 8,986 | 0.37% | N/A |
| | Independent | David Gatchell | 7,645 | 0.32% | N/A |
| Majority | Majority | Majority | 812,241 | 33.50% | +23.56% |
| Turnout | Turnout | Turnout | 2,424,585 | 66.34% | |
| | Republican hold | Republican hold | Swing | | |

## Texas

Texas has not elected a Democrat in a statewide election since 1994, but according to pre-election Rasmussen polling, senator John Cornyn had an approval rating of 50%. Texas House of Representatives member and Afghanistan War veteran Rick Noriega secured his place as Cornyn's Democratic challenger in the March 4 primary, beating out opponents Gene Kelly, Ray McMurrey, and Rhett Smith. The same Rasmussen poll showed Cornyn leading Noriega by a narrow four percentage points - 47% to 43%.
Christian activist Larry Kilgore of Mansfield, Texas, was a Republican challenger for the March 2008 primary election, but Cornyn easily won the Republican primary.
There were three Libertarians, including 2006 LP senate nominee Scott Jameson, running for their party's nomination. In addition, the Green Party of Texas sought ballot access for its candidate David B. Collins.
In the end, John Cornyn won re-election, 55%-43%
Democratic primary :
| Party | Candidate | Votes | % |
| Democratic | Rick Noriega | 1,110,579 | 51.01% |
| Democratic | Gene Kelly | 584,966 | 26.87% |
| Democratic | Ray McMurrey | 269,402 | 12.37% |
| Democratic | Rhett Smith | 213,305 | 9.75% |
Republican Primary :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | John Cornyn (incumbent) | 997,216 | 81.48% | +4.17% |
| | Republican | Larry Kilgore | 226,649 | 18.52% | +0.00% |
2008 Texas U.S. Senate general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | John Cornyn (incumbent) | 4,337,469 | 54.82% | −0.48% |
| | Democratic | Rick Noriega | 3,389,365 | 42.83% | −0.50% |
| | Libertarian | Yvonne Adams Schick | 185,241 | 2.34% | +1.55% |
| Majority | Majority | Majority | 948,104 | | |
| Turnout | Turnout | Turnout | 7,912,075 | 58.28% | |
| | Republican hold | Republican hold | Swing | | |

## Virginia

John Warner announced on August 31, 2007, that he would not seek re-election for another term. Former Governor Jim Gilmore, who dropped out of the 2008 presidential election, was the Republican nominee for the seat. Popular Democratic former Governor Mark Warner (no relation) was the Democratic nominee for the race. Polling showed him as a strong favorite to win the seat.
When asked whether the Republicans were abandoning their hopes of holding onto Warner's seat, senator John Ensign, the chairman of the National Republican Senatorial Committee, responded that "You don't waste money on races that don't need it or you can't win."
In one of the first senate races called on election day, Warner won, taking 65% of the vote, with Gilmore winning 34%. Since Democrat Jim Webb had defeated incumbent Republican George Allen for Virginia's other Senate seat in 2006, Virginia's senate delegation flipped from entirely Republican to entirely Democratic in just two years.
Virginia general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Mark Warner | 2,369,327 | 65.03% | +65.03% |
| | Republican | Jim Gilmore | 1,228,830 | 33.72% | −48.85% |
| | Independent Greens | Glenda Parker | 21,690 | 0.60% | +0.60% |
| | Libertarian | Bill Redpath | 20,269 | 0.56% | +0.56% |
| | Write-ins | | 3,178 | 0.09% | −0.47% |
| Majority | Majority | Majority | 1,140,497 | 31.30% | −41.53% |
| Turnout | Turnout | Turnout | 3,643,294 | | |
| | Democratic gain from Republican | Democratic gain from Republican | Swing | | |

## West Virginia

Senator Jay Rockefeller, great-grandson of oil tycoon John D. Rockefeller, sought a fifth term representing West Virginia. Even though West Virginia is a historically Democratic state, in which the party had a 50-32% edge in party affiliation over the Republicans in the 2004 elections, the state party is more conservative than the national party, giving its votes to President George W. Bush in that election and in 2000. Democrats Sheirl Fletcher and Billy Hendricks challenged Rockefeller in the primary but were defeated. The Republican nominee was Jay Wolfe of Salem, a former State Senator.
Rockefeller handily won on election day, being re-elected with 64% of the vote. Wolfe had 36%.
2008 West Virginia U.S. Senate Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jay Rockefeller (Incumbent) | 271,370 | 77.1% |
| | Democratic | Sheirl Fletcher | 51,073 | 14.5% |
| | Democratic | Billy Hendricks | 29,707 | 8.4% |
| Turnout | Turnout | Turnout | 352,150 | |
Republican primary :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Jay Wolfe | N/A | 100.00% | |
| Turnout | Turnout | Turnout | | 100.00% | |
West Virginia general :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jay Rockefeller (Incumbent) | 447,560 | 63.7% | +0.6% |
| | Republican | Jay Wolfe | 254,629 | 36.3% | −0.6% |
| Majority | Majority | Majority | 192,931 | | |
| Turnout | Turnout | Turnout | 702,189 | | |
| | Democratic hold | Democratic hold | Swing | | |

## Wyoming
### Wyoming (regular)

Incumbent Republican Mike Enzi was considered likely to be re-elected without significant opposition for a third term in strongly Republican Wyoming. His Democratic opponent was Chris Rothfuss, a professor at the University of Wyoming and a chemical engineer, nanotechnologist, and diplomat. Pre-election polling indicated that Enzi led Rothfuss by 24%.
Enzi won another term, 76%-24%.
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Chris Rothfuss | 14,221 | 62.38% |
| | Democratic | Al Hamburg | 8,578 | 37.62% |
| Total votes | Total votes | Total votes | 22,799 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Mike Enzi (Incumbent) | 69,195 | 100.00% |
| Total votes | Total votes | Total votes | 69,195 | 100.00% |
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Mike Enzi (incumbent) | 189,046 | 75.63% | +2.68% |
| | Democratic | Chris Rothfuss | 60,631 | 24.26% | −2.79% |
| | Write-ins | | 269 | 0.11% | |
| Majority | Majority | Majority | 128,415 | 51.38% | +5.47% |
| Turnout | Turnout | Turnout | 249,946 | | |
| | Republican hold | Republican hold | Swing | | |

### Wyoming (special)

Republican John Barrasso was appointed by Governor Dave Freudenthal (D) on June 22, 2007, to fill the senate seat of Republican Craig L. Thomas, who died on June 4. Wyoming law requires that the interim senator be affiliated with the same political party as the departed senator. Barrasso ran in the November 4, 2008, special election, held on the day of the 2008 presidential election, to serve out the remainder of Thomas's term, which expires in January 2013.
On the Democratic side, Casper City Councilman Keith Goodenough announced his candidacy. In the primary on August 19, Goodenough was defeated by a political newcomer, Gillette defense attorney Nick Carter, who became Barrasso's opponent in the general election.
Barrasso won on Election Day, taking 73% of the vote and winning every county in the state.
Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Nick Carter | 12,316 | 50.68% |
| | Democratic | Keith Goodenough | 11,984 | 49.32% |
| Total votes | Total votes | Total votes | 22,799 | 100.00% |
Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | John Barrasso (Incumbent) | 68,194 | 100.00% |
| Total votes | Total votes | Total votes | 68,194 | 100.00% |
Wyoming special election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | John Barrasso (Incumbent) | 183,063 | 73.35% | +3.37% |
| | Democratic | Nick Carter | 66,202 | 26.53% | −3.33% |
| | None | Write-ins | 293 | 0.12% | |
| Majority | Majority | Majority | 116,861 | 46.83% | +6.70% |
| Turnout | Turnout | Turnout | 249,558 | | |
| | Republican hold | Republican hold | Swing | | |