# 2018 United States Senate elections

The 2018 United States Senate elections were held on November 6, 2018. Among the 100 seats, the 33 of Class 1 were contested in regular elections while 2 others were contested in special elections due to Senate vacancies in Minnesota and Mississippi. The regular election winners were elected to 6-year terms running from January 3, 2019, to January 3, 2025. Senate Democrats had 26 seats up for election (including the seats of 2 Independents who caucus with them), while Senate Republicans had 9 seats up for election.
To maintain their working majority of 50 senators and their party's vice president's tie-breaking vote, Republicans could only afford a net loss of 1 seat in these elections. The Republicans had a 52–48 majority after the 2016 elections, but they lost a seat in Alabama after Jeff Sessions resigned to become U.S. attorney general and Doug Jones, a Democrat, won in the subsequent special election. 3 Republican-held seats were open as a result of retirements in Tennessee, Utah, and Arizona. Although every Democratic incumbent ran for re-election, Democrats faced an extremely unfavorable map, defending 26 seats, of which 10 were in states won by Donald Trump in the 2016 presidential election, and 5 of those where Trump had won by more than 10%. Republicans, however, only had to defend 9 seats, of which only 1 was in a state won by Hillary Clinton in 2016.
The Republicans increased their majority by defeating Democratic incumbents in Florida, Indiana, Missouri, and North Dakota, and holding the open seats in Tennessee and Utah. Democrats won 2 Republican-held seats, defeating an incumbent in Nevada and winning the open seat in Arizona. This was the first time Republicans gained Class 1 Senate seats since 1994.
The results for this election cycle were the only significant gains made by the Republicans in what was otherwise characterized as a "blue wave" election. The Republican gains in the Senate and the Democratic gains in the House marked the first midterm election cycle since 1970 in which the president's party made net gains in one chamber of Congress while suffering net losses in the other, which also occurred in 1914, 1962, and 2022. This was also the first midterm election cycle since 2002 in which any incumbents of the non-presidential party lost re-election. The number of defeated non-presidential party incumbents (4) was the most since the 1934 mid-terms. To date, this remains the last time that Democrats won a Senate election in Montana, Ohio, and West Virginia.

## Partisan composition

Among the 33 Class 1 Senate seats up for regular election in 2018, twenty-three were held by Democrats, two by independents who caucused with the Senate Democrats and eight by Republicans. Class Two seats in Minnesota and Mississippi held by interim appointees were also up for election; both incumbent appointees sought election to finish their unexpired terms.
Democrats targeted Republican-held Senate seats in Arizona (open seat) and Nevada. Seats in Texas, Mississippi (at least one of the two seats) and Tennessee (open seat) were also competitive for the Democrats. Republicans targeted Democratic-held seats in Indiana, Missouri, Montana, North Dakota and West Virginia, all of which were won by Republicans in both the 2012 and 2016 presidential elections. Seats in Florida, Ohio, Pennsylvania, Wisconsin and Michigan, all of which were won by Obama in 2008 and 2012 but by Trump in 2016, were also targeted by Republicans. The Democratic-held seat in New Jersey was also considered unexpectedly competitive due to corruption allegations surrounding the Democratic incumbent.
The map was widely characterized as extremely unfavorable to Democrats, as Democrats were defending 26 states while Republicans were defending nine. Of these seats, Democrats were defending ten in states won by Donald Trump in the 2016 presidential election, while Republicans were only defending one seat in a state won by Hillary Clinton in 2016. According to FiveThirtyEight, Democrats faced the most unfavorable Senate map in 2018 that any party has ever faced in any election.

## Results summary

| Parties | Parties | Parties | | | | | | | Total |
| Parties | Parties | Parties | Democratic | Republican | Independent | Libertarian | Green | Other | Total |
| Last elections (2016) | Last elections (2016) | Last elections (2016) | 46 | 52 | 2 | 0 | 0 | 0 | 100 |
| Before these elections | Before these elections | Before these elections | 47 | 51 | 2 | 0 | 0 | 0 | 100 |
| Not up | Not up | Not up | 23 | 42 | 0 | — | — | — | 65 |
| | Class 2 (2014→2020) | Class 2 (2014→2020) | 11 | 20 | 0 | — | — | — | 31 |
| | Class 3 (2016→2022) | Class 3 (2016→2022) | 12 | 22 | 0 | — | — | — | 34 |
| Up | Up | Up | 24 | 9 | 2 | — | — | — | 35 |
| | Class 1 (2012→2018) | Class 1 (2012→2018) | 23 | 8 | 2 | — | — | — | 33 |
| | Special: Class 2 | Special: Class 2 | 1 | 1 | 0 | — | — | — | 2 |
| Regular elections |||||||||
| | Incumbent retired | Incumbent retired | 0 | 3 | 0 | — | — | — | 3 |
| | | Held by same party | — | 2 | — | — | — | — | 2 |
| | | Replaced by other party | 1 Republican replaced by 1 Democrat | 1 Republican replaced by 1 Democrat | | | | | 1 |
| | | Result | 1 | 2 | 0 | 0 | 0 | 0 | 3 |
| | Incumbent ran | Incumbent ran | 23 | 5 | 2 | — | — | — | 30 |
| | | Won re-election | 19 | 4 | 2 | — | — | — | 25 |
| | | Lost re-election | 1 Republican replaced by 1 Democrat 4 Democrats replaced by 4 Republicans | 1 Republican replaced by 1 Democrat 4 Democrats replaced by 4 Republicans | | | | | 5 |
| | | Result | 20 | 8 | 2 | 0 | 0 | 0 | 30 |
| Special elections |||||||||
| | Appointee ran | Appointee ran | 1 | 1 | — | — | — | — | 2 |
| | | Appointee elected | 1 | 1 | — | — | — | — | 2 |
| | | Result | 1 | 1 | 0 | 0 | 0 | 0 | 2 |
| | Total elected | Total elected | 22 | 11 | 2 | 0 | 0 | 0 | 35 |
| | Net gain/loss | Net gain/loss | 2 | 2 | | | | | 2 |
| | Nationwide vote | Nationwide vote | 52,224,867 | 34,722,926 | 808,370 | 590,051 | 200,599 | 1,262,765 | 90,473,222 |
| | | Share | 58.17% | 38.67% | 0.90% | 0.66% | 0.22% | 1.41% | 100% |
| Result | Result | Result | 45 | 53 | 2 | 0 | 0 | 0 | 100 |
Source: Clerk of the U.S. House of Representatives.

## Change in composition

Each block represents one of the one hundred seats in the Senate. "D#" is a Democratic senator, "I#" is an independent senator and "R#" is a Republican senator. Arranged so parties are separated and a majority is clear by crossing the middle.

### Before the elections

Each block indicates an incumbent senator's actions going into the election. Some "Ran" for re-election, some "Retired," and those without a note were not up for election this cycle. Before the elections, Republicans held 51 seats, Democrats held 47, and Independents held 2.
After the 2017 Senate special election in Alabama on the start of the second session in the 115th Congress.
| D$_1$ Ala. Gain | 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$_{24}$ Calif. Ran | D$_{25}$ Conn. Ran | D$_{26}$ Del. Ran | D$_{27}$ Fla. Ran | D$_{28}$ Hawaii Ran | D$_{29}$ Ind. Ran | D$_{30}$ Md. Ran |
| D$_{40}$ N.D. Ran | D$_{39}$ N.Y. Ran | D$_{38}$ N.M. Ran | D$_{37}$ N.J. Ran | D$_{36}$ Mont. Ran | D$_{35}$ Mo. Ran | D$_{34}$ Minn. (sp) Ran | D$_{33}$ Minn. (reg) Ran | D$_{32}$ Mich. Ran | D$_{31}$ Mass. Ran |
| D$_{41}$ Ohio Ran | D$_{42}$ Penn. Ran | D$_{43}$ R.I. Ran | D$_{44}$ Va. Ran | D$_{45}$ Wash. Ran | D$_{46}$ W.Va. Ran | D$_{47}$ Wis. Ran | I$_1$ Maine Ran | I$_2$ Vt. Ran | R$_{51}$ Utah Retired |
| R$_{51}$ Utah Retired |||||||||
| R$_{41}$ | R$_{42}$ | R$_{43}$ Miss. (reg) Ran | R$_{44}$ Miss. (sp) Ran | R$_{45}$ Neb. Ran | R$_{46}$ Nev. Ran | R$_{47}$ Texas Ran | R$_{48}$ Wyo. Ran | R$_{49}$ Ariz. Retired | R$_{50}$ Tenn. Retired |
| 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$_{10}$ |

### After the elections

Some senators were "Re-elected," some were a "Gain" in the seat from the other party (either by beating an incumbent or by winning an open seat), some were a "Hold" by the same party but with a different senator, and those without a note were not up for election this year.
After these elections, Democrats had 45 seats, independents had 2, and Republicans had 53.
| 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$_{24}$ Calif. Re-elected | D$_{25}$ Conn. Re-elected | D$_{26}$ Del. Re-elected | D$_{27}$ Hawaii Re-elected | D$_{28}$ Md. Re-elected | D$_{29}$ Mass. Re-elected | D$_{30}$ Mich. Re-elected |
| D$_{40}$ Va. Re-elected | D$_{39}$ R.I. Re-elected | D$_{38}$ Pa. Re-elected | D$_{37}$ Ohio Re-elected | D$_{36}$ N.Y. Re-elected | D$_{35}$ N.M. Re-elected | D$_{34}$ N.J. Re-elected | D$_{33}$ Mont. Re-elected | D$_{32}$ Minn. (sp) Elected | D$_{31}$ Minn. (reg) Re-elected |
| D$_{41}$ Wash. Re-elected | D$_{42}$ W.Va. Re-elected | D$_{43}$ Wis. Re-elected | D$_{44}$ Ariz. Gain | D$_{45}$ Nev. Gain | I$_1$ Maine Re-elected | I$_2$ Vt. Re-elected | R$_{53}$ N.D. Gain | R$_{52}$ Mo. Gain | R$_{51}$ Ind. Gain |
| R$_{51}$ Ind. Gain |||||||||
| R$_{41}$ | R$_{42}$ | R$_{43}$ Miss. (reg) Re-elected | R$_{44}$ Miss. (sp) Elected | R$_{45}$ Neb. Re-elected | R$_{46}$ Tenn. Hold | R$_{47}$ Tex. Re-elected | R$_{48}$ Utah Hold | R$_{49}$ Wyo. Re-elected | R$_{50}$ Fla. Gain |
| 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 R$_#$ Republican I$_#$ Independent, caucusing with Democrats |

## Predictions

Several sites and individuals publish predictions of competitive seats. These predictions look at factors such as the strength of the incumbent (if the incumbent is 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 assign ratings to each seat, indicating the predicted advantage that a party has 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" or "favored": significant, but surmountable, advantage
* "safe" or "solid": near-certain chance of victory
| Constituency | Constituency | Incumbent | Incumbent | 2018 election ratings | 2018 election ratings | 2018 election ratings | 2018 election ratings | 2018 election ratings | 2018 election ratings | 2018 election ratings | 2018 election ratings | 2018 election ratings | 2018 election ratings | 2018 election ratings |
| State | PVI | Senator | Last election | Cook Oct 26, 2018 | IE Nov 1, 2018 | Sabato Nov 5, 2018 | NYT Nov 5, 2018 | Fox News Nov 5, 2018 | CNN Nov 2, 2018 | RCP Nov 5, 2018 | Daily Kos Nov 5, 2018 | Politico Nov 5, 2018 | 538 Nov 6, 2018 | Result |
| Arizona | R+5 | Jeff Flake (retiring) | 49.2% R | Tossup | Tilt D (flip) | Lean D (flip) | Tossup | Tossup | Tossup | Tossup | Tossup | Tossup | Lean D (flip) | Sinema 50.0% D (flip) |
| California | D+12 | Dianne Feinstein | 62.5% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Feinstein 54.2% D |
| Connecticut | D+6 | Chris Murphy | 54.8% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Murphy 59.5% D |
| Delaware | D+6 | Tom Carper | 66.4% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Carper 60.0% D |
| Florida | R+2 | Bill Nelson | 55.2% D | Tossup | Tilt D | Lean D | Tossup | Tossup | Tossup | Tossup | Tossup | Tossup | Lean D | Scott 50.1% R (flip) |
| Hawaii | D+18 | Mazie Hirono | 62.6% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Hirono 71.2% D |
| Indiana | R+9 | Joe Donnelly | 50.0% D | Tossup | Tossup | Lean R (flip) | Tossup | Tossup | Tossup | Tossup | Tossup | Tossup | Lean D | Braun 50.7% R (flip) |
| Maine | D+3 | Angus King | 52.9% I | Safe I | Safe I | Safe I | Safe I | Likely I | Safe I | Safe I | Safe I | Safe I | Safe I | King 54.3% I |
| Maryland | D+12 | Ben Cardin | 56.0% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Cardin 64.9% D |
| Massachusetts | D+12 | Elizabeth Warren | 53.7% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Warren 60.3% D |
| Michigan | D+1 | Debbie Stabenow | 58.8% D | Likely D | Safe D | Safe D | Likely D | Likely D | Likely D | Lean D | Safe D | Likely D | Safe D | Stabenow 52.3% D |
| Minnesota (regular) | D+1 | Amy Klobuchar | 65.2% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Klobuchar 60.3% D |
| Minnesota (special) | D+1 | Tina Smith | Appointed (2018) | Lean D | Likely D | Likely D | Lean D | Likely D | Likely D | Lean D | Likely D | Likely D | Likely D | Smith 53.0% D |
| Mississippi (regular) | R+9 | Roger Wicker | 57.1% R | Safe R | Safe R | Safe R | Safe R | Likely R | Safe R | Safe R | Safe R | Safe R | Safe R | Wicker 58.5% R |
| Mississippi (special) | R+9 | Cindy Hyde-Smith | Appointed (2018) | Lean R | Safe R | Likely R | Lean R | Lean R | Safe R | Likely R | Likely R | Likely R | Lean R | Hyde-Smith 53.6% R |
| Missouri | R+9 | Claire McCaskill | 54.8% D | Tossup | Tilt R (flip) | Lean R (flip) | Tossup | Tossup | Tossup | Tossup | Tossup | Tossup | Tossup | Hawley 51.4% R (flip) |
| Montana | R+11 | Jon Tester | 48.6% D | Tossup | Tilt D | Lean D | Tossup | Lean D | Lean D | Tossup | Tossup | Lean D | Likely D | Tester 50.3% D |
| Nebraska | R+14 | Deb Fischer | 57.8% R | Safe R | Safe R | Safe R | Safe R | Likely R | Safe R | Safe R | Safe R | Safe R | Safe R | Fischer 57.7% R |
| Nevada | D+1 | Dean Heller | 45.9% R | Tossup | Tilt D (flip) | Lean D (flip) | Tossup | Tossup | Tossup | Tossup | Tossup | Tossup | Tossup | Rosen 50.4% D (flip) |
| New Jersey | D+7 | Bob Menendez | 58.9% D | Tossup | Likely D | Likely D | Tossup | Lean D | Lean D | Lean D | Lean D | Lean D | Likely D | Menendez 54.0% D |
| New Mexico | D+3 | Martin Heinrich | 51.0% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Heinrich 54.1% D |
| New York | D+11 | Kirsten Gillibrand | 72.2% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Gillibrand 67.0% D |
| North Dakota | R+16 | Heidi Heitkamp | 50.2% D | Lean R (flip) | Lean R (flip) | Lean R (flip) | Lean R (flip) | Likely R (flip) | Lean R (flip) | Lean R (flip) | Lean R (flip) | Lean R (flip) | Lean R (flip) | Cramer 55.4% R (flip) |
| Ohio | R+3 | Sherrod Brown | 50.7% D | Likely D | Safe D | Likely D | Likely D | Likely D | Likely D | Lean D | Likely D | Likely D | Safe D | Brown 53.4% D |
| Pennsylvania | EVEN | Bob Casey Jr. | 53.7% D | Likely D | Safe D | Safe D | Likely D | Likely D | Likely D | Likely D | Safe D | Likely D | Safe D | Casey 55.7% D |
| Rhode Island | D+10 | Sheldon Whitehouse | 64.8% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Whitehouse 61.5% D |
| Tennessee | R+14 | Bob Corker (retiring) | 64.9% R | Tossup | Lean R | Lean R | Tossup | Lean R | Tossup | Tossup | Lean R | Lean R | Likely R | Blackburn 54.7% R |
| Texas | R+8 | Ted Cruz | 56.5% R | Tossup | Likely R | Lean R | Tossup | Lean R | Lean R | Lean R | Lean R | Lean R | Likely R | Cruz 50.9% R |
| Utah | R+20 | Orrin Hatch (retiring) | 65.3% R | Safe R | Safe R | Safe R | Safe R | Likely R | Safe R | Safe R | Safe R | Safe R | Safe R | Romney 62.6% R |
| Vermont | D+15 | Bernie Sanders | 71.0% I | Safe I | Safe I | Safe I | Safe I | Likely I | Safe I | Safe I | Safe I | Safe I | Safe I | Sanders 67.4% I |
| Virginia | D+1 | Tim Kaine | 52.3% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Kaine 57.0% D |
| Washington | D+7 | Maria Cantwell | 60.5% D | Safe D | Safe D | Safe D | Safe D | Likely D | Safe D | Safe D | Safe D | Safe D | Safe D | Cantwell 58.4% D |
| West Virginia | R+20 | Joe Manchin | 60.6% D | Lean D | Tilt D | Lean D | Lean D | Lean D | Lean D | Tossup | Lean D | Lean D | Likely D | Manchin 49.6% D |
| Wisconsin | EVEN | Tammy Baldwin | 51.4% D | Likely D | Safe D | Likely D | Likely D | Likely D | Likely D | Lean D | Likely D | Likely D | Safe D | Baldwin 55.4% D |
| Wyoming | R+25 | John Barrasso | 75.7% R | Safe R | Safe R | Safe R | Safe R | Likely R | Safe R | Safe R | Safe R | Safe R | Safe R | Barrasso 67.0% R |
| Overall | Overall | Overall | Overall | D - 43 R - 48 9 tossups | D - 48 R - 51 1 tossup | D - 48 R - 52 0 tossups | D - 43 R - 48 9 tossups | D - 45 R - 50 5 tossups | D - 45 R - 49 6 tossups | D - 43 R - 49 8 tossups | D - 44 R - 50 6 tossups | D - 45 R - 50 5 tossups | D - 48 R - 50 2 tossups | Results: D - 47 R - 53 |

## Election dates

These are the election dates for the regularly scheduled general elections.
| State | Filing deadline | Primary election | Primary run-off (if necessary) | General election | Poll closing (Eastern Time) |
| Arizona | May 30, 2018 | August 28, 2018 | N/A | November 6, 2018 | 9pm |
| California | March 9, 2018 | June 5, 2018 | N/A | November 6, 2018 | 11pm |
| Connecticut | June 12, 2018 | August 14, 2018 | N/A | November 6, 2018 | 8pm |
| Delaware | July 10, 2018 | September 6, 2018 | N/A | November 6, 2018 | 8pm |
| Florida | May 4, 2018 | August 28, 2018 | N/A | November 6, 2018 | 7pm and 8pm |
| Hawaii | June 5, 2018 | August 11, 2018 | N/A | November 6, 2018 | 11pm |
| Indiana | February 9, 2018 | May 8, 2018 | N/A | November 6, 2018 | 6pm and 7pm |
| Maine | March 15, 2018 | June 12, 2018 | N/A | November 6, 2018 | 8pm |
| Maryland | February 27, 2018 | June 26, 2018 | N/A | November 6, 2018 | 8pm |
| Massachusetts | June 5, 2018 | September 4, 2018 | N/A | November 6, 2018 | 8pm |
| Michigan | April 24, 2018 | August 7, 2018 | N/A | November 6, 2018 | 8pm and 9pm |
| Minnesota | June 5, 2018 | August 14, 2018 | N/A | November 6, 2018 | 9pm |
| Mississippi | March 1, 2018 | June 5, 2018 | June 26, 2018 | November 6, 2018 | 8pm |
| Mississippi (special) | March 26, 2018 | November 6, 2018 | N/A | November 27, 2018 | 8pm |
| Missouri | March 27, 2018 | August 7, 2018 | N/A | November 6, 2018 | 8pm |
| Montana | March 12, 2018 | June 5, 2018 | N/A | November 6, 2018 | 10pm |
| Nebraska | March 1, 2018 | May 15, 2018 | N/A | November 6, 2018 | 9pm |
| Nevada | March 16, 2018 | June 12, 2018 | N/A | November 6, 2018 | 10pm |
| New Jersey | April 2, 2018 | June 5, 2018 | N/A | November 6, 2018 | 8pm |
| New Mexico | March 13, 2018 | June 5, 2018 | N/A | November 6, 2018 | 9pm |
| New York | April 12, 2018 | June 26, 2018 | N/A | November 6, 2018 | 9pm |
| North Dakota | April 9, 2018 | June 12, 2018 | N/A | November 6, 2018 | 8pm and 9pm |
| Ohio | February 7, 2018 | May 8, 2018 | N/A | November 6, 2018 | 7:30pm |
| Pennsylvania | March 20, 2018 | May 15, 2018 | N/A | November 6, 2018 | 8pm |
| Rhode Island | June 27, 2018 | September 12, 2018 | N/A | November 6, 2018 | 8pm |
| Tennessee | April 5, 2018 | August 2, 2018 | N/A | November 6, 2018 | 8pm |
| Texas | December 11, 2017 | March 6, 2018 | May 22, 2018 (unnecessary) | November 6, 2018 | 8pm and 9pm |
| Utah | March 15, 2018 | June 26, 2018 | N/A | November 6, 2018 | 10pm |
| Vermont | May 31, 2018 | August 14, 2018 | N/A | November 6, 2018 | 7pm |
| Virginia | March 29, 2018 | June 12, 2018 | N/A | November 6, 2018 | 7pm |
| Washington | May 18, 2018 | August 7, 2018 | N/A | November 6, 2018 | 11pm |
| West Virginia | January 27, 2018 | May 8, 2018 | N/A | November 6, 2018 | 7:30pm |
| Wisconsin | June 1, 2018 | August 14, 2018 | N/A | November 6, 2018 | 9pm |
| Wyoming | June 1, 2018 | August 21, 2018 | N/A | November 6, 2018 | 9pm |

## Gains and losses
### Retirements

Three Republicans retired instead of seeking re-election.
| State | Senator | Replaced by |
| Arizona | Jeff Flake | Kyrsten Sinema |
| Tennessee | Bob Corker | Marsha Blackburn |
| Utah | Orrin Hatch | Mitt Romney |

### Defeats

Four Democrats and one Republican sought re-election but lost in the general election.
| State | Senator | Replaced by |
| Florida | Bill Nelson | Rick Scott |
| Indiana | Joe Donnelly | Mike Braun |
| Missouri | Claire McCaskill | Josh Hawley |
| Nevada | Dean Heller | Jacky Rosen |
| North Dakota | Heidi Heitkamp | Kevin Cramer |

### Post-election changes

One Republican resigned before the start of the 116th Congress on December 31, 2018, and another Republican resigned during the 116th Congress for health reasons. Initially, all were replaced by Republican appointees.
| State | Senator | Replaced by |
| Arizona (Class 3) | Jon Kyl | Martha McSally |
| Georgia (Class 3) | Johnny Isakson | Kelly Loeffler |

## Race summary
### Special elections during the preceding Congress

In these special elections, the winners will be seated before January 3, 2019, when elected and qualified. They are ordered by election date, then by state and by class.
| State | Incumbent | Incumbent | Incumbent | Result | Candidates |
| State | Senator | Party | Electoral history | Result | Candidates |
| Minnesota (Class 2) | Tina Smith | DFL | 2018 (appointed) | Interim appointee elected. | ▌Y Tina Smith (DFL) 53.0% ▌Karin Housley (Republican) 42.4% ▌Sarah Wellington (Legal Marijuana Now) 3.7% ▌Jerry Trooien (Independent) 0.9% |
| Mississippi (Class 2) | Cindy Hyde-Smith | Republican | 2018 (appointed) | Interim appointee elected. | ▌Y Cindy Hyde-Smith (Republican) 53.6% ▌Mike Espy (Democratic) 46.4% |

### Elections leading to the next Congress

In these general elections, the winners were elected for the term beginning January 3, 2019.
All of the elections involve the Class 1 seats and they are ordered by state.
| State | Incumbent | Incumbent | Incumbent | Result | Candidates |
| State | Senator | Party | Electoral history | Result | Candidates |
| Arizona | Jeff Flake | Republican | 2012 | Incumbent retired. Democratic gain. | ▌Y Kyrsten Sinema (Democratic) 50.0% ▌Martha McSally (Republican) 47.6% ▌Angela Green (Green) 2.4% |
| California | Dianne Feinstein | Democratic | 1992 (special) 1994 2000 2006 2012 | Incumbent re-elected. | ▌Y Dianne Feinstein (Democratic) 54.2% ▌Kevin de León (Democratic) 45.8% |
| Connecticut | Chris Murphy | Democratic | 2012 | Incumbent re-elected. | ▌Y Chris Murphy (Democratic) 59.5% ▌Matthew Corey (Republican) 39.4% Others ▌Richard Lion (Libertarian) 0.6% ▌Jeff Russell (Green) 0.5% |
| Delaware | Tom Carper | Democratic | 2000 2006 2012 | Incumbent re-elected. | ▌Y Tom Carper (Democratic) 60.0% ▌Robert Arlett (Republican) 37.8% Others ▌Demitri Theodoropoulos (Green) 1.2% ▌Nadine Frost (Libertarian) 1.1% |
| Florida | Bill Nelson | Democratic | 2000 2006 2012 | Incumbent lost re-election. Republican gain. Winner delayed term until January 8, 2019, to finish his term as Governor of Florida. | ▌Y Rick Scott (Republican) 50.1% ▌Bill Nelson (Democratic) 49.9% |
| Hawaii | Mazie Hirono | Democratic | 2012 | Incumbent re-elected. | ▌Y Mazie Hirono (Democratic) 71.2% ▌Ron Curtis (Republican) 28.8% |
| Indiana | Joe Donnelly | Democratic | 2012 | Incumbent lost re-election. Republican gain. | ▌Y Mike Braun (Republican) 50.9% ▌Joe Donnelly (Democratic) 45.0% ▌Lucy Brenton (Libertarian) 4.0% |
| Maine | Angus King | Independent | 2012 | Incumbent re-elected. | ▌Y Angus King (Independent) 54.3% ▌Eric Brakey (Republican) 35.2% ▌Zak Ringelstein (Democratic) 10.4% |
| Maryland | Ben Cardin | Democratic | 2006 2012 | Incumbent re-elected. | ▌Y Ben Cardin (Democratic) 64.9% ▌Tony Campbell (Republican) 30.3% ▌Neal Simon (Independent) 3.7% ▌Arvin Vohra (Libertarian) 1.0% |
| Massachusetts | Elizabeth Warren | Democratic | 2012 | Incumbent re-elected. | ▌Y Elizabeth Warren (Democratic) 60.4% ▌Geoff Diehl (Republican) 36.2% ▌Shiva Ayyadurai (Independent) 3.4% |
| Michigan | Debbie Stabenow | Democratic | 2000 2006 2012 | Incumbent re-elected. | ▌Y Debbie Stabenow (Democratic) 52.3% ▌John James (Republican) 45.8% Others ▌Marcia Squier (Independent) 1.0% ▌George Huffman III (Constitution) 0.6% ▌John Wilhelm (Natural Law) 0.4% |
| Minnesota | Amy Klobuchar | DFL | 2006 2012 | Incumbent re-elected. | ▌Y Amy Klobuchar (DFL) 60.3% ▌Jim Newberger (Republican) 36.2% ▌Dennis Schuller (Legal Marijuana Now) 2.5% ▌Paula M. Overby (Green) 0.9% |
| Mississippi | Roger Wicker | Republican | 2007 (appointed) 2008 (special) 2012 | Incumbent re-elected. | ▌Y Roger Wicker (Republican) 58.5% ▌David Baria (Democratic) 39.5% Others ▌Danny Bedwell (Libertarian) 1.4% ▌Shawn O'Hara (Reform) 0.6% |
| Missouri | Claire McCaskill | Democratic | 2006 2012 | Incumbent lost re-election. Republican gain. | ▌Y Josh Hawley (Republican) 51.4% ▌Claire McCaskill (Democratic) 45.6% Others ▌Craig O'Dear (Independent) 1.4% ▌Japheth Campbell (Libertarian) 1.1% ▌Jo Crain (Green) 0.5% |
| Montana | Jon Tester | Democratic | 2006 2012 | Incumbent re-elected. | ▌Y Jon Tester (Democratic) 50.3% ▌Matt Rosendale (Republican) 46.8% ▌Rick Breckenridge (Libertarian) 2.9% |
| Nebraska | Deb Fischer | Republican | 2012 | Incumbent re-elected. | ▌Y Deb Fischer (Republican) 57.7% ▌Jane Raybould (Democratic) 38.6% ▌Jim Schultz (Libertarian) 3.7% |
| Nevada | Dean Heller | Republican | 2011 (appointed) 2012 | Incumbent lost re-election. Democratic gain. | ▌Y Jacky Rosen (Democratic) 50.4% ▌Dean Heller (Republican) 45.4% Others ▌Barry Michaels (Independent) 1.0% ▌Tim Hagan (Libertarian) 0.9% ▌Kamau Bakari (Independent American) 0.7% |
| New Jersey | Bob Menendez | Democratic | 2006 (appointed) 2006 2012 | Incumbent re-elected. | ▌Y Bob Menendez (Democratic) 54.0% ▌Bob Hugin (Republican) 42.8% Others ▌Madelyn Hoffman (Green) 0.8% ▌Murray Sabrin (Libertarian) 0.7% ▌Natalie Rivera (For The People) 0.6% ▌Tricia Flanagan (New Day NJ) 0.5% ▌Kevin Kimple (Make It Simple) 0.3% ▌Hank Schroeder (Economic Growth) 0.3% |
| New Mexico | Martin Heinrich | Democratic | 2012 | Incumbent re-elected. | ▌Y Martin Heinrich (Democratic) 54.1% ▌Mick Rich (Republican) 30.5% ▌Gary Johnson (Libertarian) 15.4% |
| New York | Kirsten Gillibrand | Democratic | 2009 (appointed) 2010 (special) 2012 | Incumbent re-elected. | ▌Y Kirsten Gillibrand (Democratic) 67.0% ▌Chele Chiavacci Farley (Republican) 33.0% |
| North Dakota | Heidi Heitkamp | Democratic-NPL | 2012 | Incumbent lost re-election. Republican gain. | ▌Y Kevin Cramer (Republican) 55.5% ▌Heidi Heitkamp (Democratic-NPL) 44.5% |
| Ohio | Sherrod Brown | Democratic | 2006 2012 | Incumbent re-elected. | ▌Y Sherrod Brown (Democratic) 53.4% ▌Jim Renacci (Republican) 46.6% |
| Pennsylvania | Bob Casey Jr. | Democratic | 2006 2012 | Incumbent re-elected. | ▌Y Bob Casey Jr. (Democratic) 55.7% ▌Lou Barletta (Republican) 42.6% Others ▌Dale Kerns (Libertarian) 1.0% ▌Neal Gale (Green) 0.6% |
| Rhode Island | Sheldon Whitehouse | Democratic | 2006 2012 | Incumbent re-elected. | ▌Y Sheldon Whitehouse (Democratic) 61.6% ▌Robert Flanders (Republican) 38.4% |
| Tennessee | Bob Corker | Republican | 2006 2012 | Incumbent retired. Republican hold. | ▌Y Marsha Blackburn (Republican) 54.7% ▌Phil Bredesen (Democratic) 43.9% Others ▌Trudy Austin (Independent) 0.4% ▌Dean Hill (Independent) 0.4% ▌Kris Todd (Independent) 0.2% ▌John Carico (Independent) 0.2% ▌Breton Phillips (Independent) 0.1% ▌Kevin McCants (Independent) 0.1% |
| Texas | Ted Cruz | Republican | 2012 | Incumbent re-elected. | ▌Y Ted Cruz (Republican) 50.9% ▌Beto O'Rourke (Democratic) 48.3% ▌Neal Dikeman (Libertarian) 0.8% |
| Utah | Orrin Hatch | Republican | 1976 1982 1988 1994 2000 2006 2012 | Incumbent retired. Republican hold. | ▌Y Mitt Romney (Republican) 62.6% ▌Jenny Wilson (Democratic) 30.9% ▌Tim Aalders (Constitution) 2.7% ▌Craig Bowden (Libertarian) 2.6% ▌Reed McCandless (Independent American) 1.2% |
| Vermont | Bernie Sanders | Independent | 2006 2012 | Incumbent re-elected. | ▌Y Bernie Sanders (Independent) 67.4% ▌Lawrence Zupan (Republican) 27.5% |
| Virginia | Tim Kaine | Democratic | 2012 | Incumbent re-elected. | ▌Y Tim Kaine (Democratic) 57.1% ▌Corey Stewart (Republican) 41.1% ▌Matt Waters (Libertarian) 1.8% |
| Washington | Maria Cantwell | Democratic | 2000 2006 2012 | Incumbent re-elected. | ▌Y Maria Cantwell (Democratic) 58.4% ▌Susan Hutchison (Republican) 41.6% |
| West Virginia | Joe Manchin | Democratic | 2010 (special) 2012 | Incumbent re-elected. | ▌Y Joe Manchin (Democratic) 49.6% ▌Patrick Morrisey (Republican) 46.3% ▌Rusty Hollen (Libertarian) 4.1% |
| Wisconsin | Tammy Baldwin | Democratic | 2012 | Incumbent re-elected. | ▌Y Tammy Baldwin (Democratic) 55.4% ▌Leah Vukmir (Republican) 44.6% |
| Wyoming | John Barrasso | Republican | 2007 (appointed) 2008 (special) 2012 | Incumbent re-elected. | ▌Y John Barrasso (Republican) 67.1% ▌Gary Trauner (Democratic) 30.1% ▌Joe Porambo (Libertarian) 2.8% |

## Closest races

In twelve races the margin of victory was under 10%.
| State | Party of winner | Margin |
| Florida | Republican (flip) | 0.12% |
| Arizona | Democratic (flip) | 2.34% |
| Texas | Republican | 2.57% |
| West Virginia | Democratic | 3.31% |
| Montana | Democratic | 3.55% |
| Nevada | Democratic (flip) | 5.03% |
| Missouri | Republican (flip) | 5.81% |
| Indiana | Republican (flip) | 5.89% |
| Michigan | Democratic | 6.51% |
| Ohio | Democratic | 6.85% |
| Mississippi (special) | Republican | 7.27% |
| California | Democratic | 8.33% |

## Arizona

One-term Republican Jeff Flake was elected with 49% of the vote in 2012. He chose not to run for re-election.
U.S. Representative Martha McSally won the Republican nomination in a three-way primary on August 28, 2018, against Joe Arpaio and Kelli Ward.
U.S. Representative Kyrsten Sinema easily secured the Democratic nomination.
Sinema defeated McSally by a slim margin; her victory became official only after six days of counting ballots.
Arizona Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Martha McSally | 357,626 | 54.57 |
| | Republican | Kelli Ward | 180,926 | 27.61 |
| | Republican | Joe Arpaio | 116,555 | 17.79 |
| | Write-in | Write-in | 191 | 0.03 |
| Total votes | Total votes | Total votes | 655,298 | 100.00 |
Arizona Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Kyrsten Sinema | 404,170 | 79.25 |
| | Democratic | Deedra Abboud | 105,800 | 20.75 |
| Total votes | Total votes | Total votes | 509,970 | 100.00 |
Arizona general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Kyrsten Sinema | 1,191,100 | 49.96% | +3.76 |
| | Republican | Martha McSally | 1,135,200 | 47.61% | –1.62 |
| | Green | Angela Green | 57,442 | 2.41% | N/A |
| | Write-in | Write-in | 566 | 0.02% | +0.01 |
| Total votes | Total votes | Total votes | 2,384,308 | 100.00% | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## California

Four-term Democrat Dianne Feinstein won a special election in 1992 and was elected to full terms in 1994, 2000, 2006, and 2012. She ran for re-election and advanced to the general election after securing the top spot in the June 5 jungle primary.
The June 5 primary ballot listed 32 candidates (Feinstein plus 31 challengers) in addition to 3 write-in candidates. There were 10 Democratic candidates, 11 Republican candidates, one Libertarian, one Peace and Freedom candidate, and 9 independent candidates. There was also a Green Party candidate who ran as a write-in.
President pro tempore of the California State Senate Kevin de León advanced to the general election for the right to challenge Feinstein after securing the second spot in the primary.
The 11 Republican candidates who ran in the primary combined for 33.2% of the vote. The top Republican candidate, James P. Bradley, received 8.3% of the vote, which put him in 3rd place at 3.8% behind the second-place finisher, Kevin DeLeon.
On November 6, Dianne Feinstein was elected to a fifth term, defeating Kevin de León.
California blanket primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Dianne Feinstein (incumbent) | 2,947,035 | 44.18 |
| | Democratic | Kevin de León | 805,446 | 12.07 |
| | Republican | James P. Bradley | 556,252 | 8.34 |
| | Republican | Arun K. Bhumitra | 350,815 | 5.26 |
| | Republican | Paul A. Taylor | 323,534 | 4.85 |
| | Republican | Erin Cruz | 267,494 | 4.01 |
| | Republican | Tom Palzer | 205,183 | 3.08 |
| | Democratic | Alison Hartson | 147,061 | 2.20 |
| | Republican | Rocky De La Fuente | 135,279 | 2.03 |
| | Democratic | Pat Harris | 126,947 | 1.90 |
| | Republican | John "Jack" Crew | 93,808 | 1.41 |
| | Republican | Patrick Little | 89,867 | 1.35 |
| | Republican | Kevin Mottus | 87,646 | 1.31 |
| | Republican | Jerry Joseph Laws | 67,140 | 1.01 |
| | Libertarian | Derrick Michael Reid | 60,000 | 0.90 |
| | Democratic | Adrienne Nicole Edwards | 56,172 | 0.84 |
| | Democratic | Douglas Howard Pierce | 42,671 | 0.64 |
| | Republican | Mario Nabliba | 39,209 | 0.59 |
| | Democratic | David Hildebrand | 30,305 | 0.45 |
| | Democratic | Donnie O. Turner | 30,101 | 0.45 |
| | Democratic | Herbert G. Peters | 27,468 | 0.41 |
| | No party preference | David Moore | 24,614 | 0.37 |
| | No party preference | Ling Ling Shi | 23,506 | 0.35 |
| | Peace and Freedom | John Parker | 22,825 | 0.34 |
| | No party preference | Lee Olson | 20,393 | 0.31 |
| | Democratic | Gerald Plummer | 18,234 | 0.27 |
| | No party preference | Jason M. Hanania | 18,171 | 0.27 |
| | No party preference | Don J. Grundmann | 15,125 | 0.23 |
| | No party preference | Colleen Shea Fernald | 13,536 | 0.20 |
| | No party preference | Rash Bihari Ghosh | 12,557 | 0.19 |
| | No party preference | Tim Gildersleeve | 8,482 | 0.13 |
| | No party preference | Michael Fahmy Girgis | 2,986 | 0.04 |
| | Write-in | Write-in | 863 | 0.01 |
| Total votes | Total votes | Total votes | 6,670,720 | 100.00 |
California general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Dianne Feinstein (incumbent) | 6,019,422 | 54.16% | –8.36 |
| | Democratic | Kevin de León | 5,093,942 | 45.84% | N/A |
| Total votes | Total votes | Total votes | 11,113,364 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Connecticut

One-term Democrat Chris Murphy was elected with 55% of the vote in 2012. He ran for re-election.
Businessmen Matthew Corey received the Republican nomination.
Chris Murphy was elected to a second term, winning nearly 60% of the vote.
Connecticut Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Matthew Corey | 99,899 | 76.54 |
| | Republican | Dominic Rapini | 30,624 | 23.46 |
| Total votes | Total votes | Total votes | 130,523 | 100.00 |
Connecticut general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Chris Murphy (incumbent) | 825,579 | 59.53% | +4.71 |
| | Republican | Matthew Corey | 545,717 | 39.35% | –3.72 |
| | Libertarian | Richard Lion | 8,838 | 0.64% | –1.02 |
| | Green | Jeff Russell | 6,618 | 0.48% | N/A |
| | Write-in | Write-in | 88 | 0.01% | –0.44 |
| Total votes | Total votes | Total votes | 1,386,840 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Delaware

Three-term Democrat Tom Carper won re-election with 66% of the vote in 2012. He announced he was running for re-election during an interview on MSNBC on July 24, 2017. He defeated Dover community activist Kerri Evelyn Harris for the Democratic nomination. Sussex County Councilman Robert Arlett won the Republican nomination.
Tom Carper defeated Arlett, winning 60% of the vote.
Delaware Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Tom Carper (incumbent) | 53,635 | 64.59 |
| | Democratic | Kerri Evelyn Harris | 29,407 | 35.41 |
| Total votes | Total votes | Total votes | 83,042 | 100.00 |
Delaware Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Rob Arlett | 25,284 | 66.77 |
| | Republican | Gene Truono | 10,587 | 27.96 |
| | Republican | Rocky De La Fuente | 1,998 | 5.28 |
| Total votes | Total votes | Total votes | 37,870 | 100.00 |
Delaware general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Tom Carper (incumbent) | 217,385 | 59.95% | –6.47 |
| | Republican | Rob Arlett | 137,127 | 37.82% | +8.87 |
| | Green | Demitri Theodoropoulos | 4,170 | 1.15% | +0.35 |
| | Libertarian | Nadine Frost | 3,910 | 1.08% | N/A |
| | Write-in | Write-in | 14 | 0.00% | N/A |
| Total votes | Total votes | Total votes | 362,606 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Florida

Three-term Democrat Bill Nelson was re-elected with 55% of the vote in 2012. He sought re-election to a fourth term in office.
Florida Governor Rick Scott won the Republican nomination. First elected in 2010 and re-elected in 2014, Scott's term as Governor of Florida was set to end by January 2019, due to term limits.
Edward Janowski was running as an independent, but did not qualify.
Scott led among ballots tallied on election night, but given the close margins of the race recounts were ordered. Final recount numbers were released following a machine and hand recount with Rick Scott maintaining a lead. On November 18, Nelson conceded to Scott. Two days later, election results were certified by the state, cementing Scott's win.
Florida Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Rick Scott | 1,456,187 | 88.61 |
| | Republican | Rocky De La Fuente | 187,209 | 11.39 |
| Total votes | Total votes | Total votes | 1,643,396 | 100.00 |
Florida general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Rick Scott | 4,099,505 | 50.05% | +7.82 |
| | Democratic | Bill Nelson (incumbent) | 4,089,472 | 49.93% | –5.30 |
| | Write-in | Write-in | 1,028 | 0.01% | +0.01 |
| Total votes | Total votes | Total votes | 8,190,005 | 100.00% | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Hawaii

One-term Democrat Mazie Hirono was elected with 63% of the vote in 2012. She ran.
Ron Curtis was the Republican nominee.
Hirono was elected to a second term by a landslide.
Hawaii Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Mazie Hirono (incumbent) | 201,679 | 100.00 |
| Total votes | Total votes | Total votes | 201,679 | 100.00 |
Hawaii Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Ron Curtis | 6,370 | 23.73 |
| | Republican | Consuelo Anderson | 5,172 | 19.26 |
| | Republican | Robert C. Helsham Sr. | 3,988 | 14.85 |
| | Republican | Thomas E. White | 3,661 | 13.64 |
| | Republican | Rocky De La Fuente | 3,065 | 11.42 |
| | Republican | George L. Berish | 1,658 | 6.18 |
| | Republican | Michael R. Hodgkiss | 1,576 | 5.87 |
| | Republican | Eddie Pirkowski | 1,358 | 5.06 |
| Total votes | Total votes | Total votes | 26,848 | 100.00 |
Hawaii general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Mazie Hirono (incumbent) | 276,316 | 71.15% | +8.55 |
| | Republican | Ron Curtis | 112,035 | 28.85% | –8.55 |
| Total votes | Total votes | Total votes | 388,351 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Indiana

One-term Democrat Joe Donnelly was elected with 50.04% of the vote in 2012. He ran. He won the Democratic primary unopposed.
State Representative Mike Braun won the May 8 Republican primary. U.S. Representatives Luke Messer and Todd Rokita also ran for the Republican nomination.
James Johnson ran as an independent.
Braun won election with 51% of the vote, defeating Joe Donnelly.
Indiana Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Joe Donnelly (incumbent) | 284,621 | 100.00 |
| Total votes | Total votes | Total votes | 284,621 | 100.00 |
Indiana Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Mike Braun | 208,602 | 41.17 |
| | Republican | Todd Rokita | 151,967 | 29.99 |
| | Republican | Luke Messer | 146,131 | 28.84 |
| Total votes | Total votes | Total votes | 506,700 | 100.00 |
Indiana general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Mike Braun | 1,158,000 | 50.73% | +6.45 |
| | Democratic | Joe Donnelly (incumbent) | 1,023,553 | 44.84% | –5.20 |
| | Libertarian | Lucy Brenton | 100,942 | 4.42% | –1.26 |
| | Write-in | Write-in | 70 | 0.00% | N/A |
| Total votes | Total votes | Total votes | 2,282,565 | 100.00% | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Maine

One-term Independent Senator Angus King was elected in a three-way race with 53% of the vote in 2012. King has caucused with the Democratic Party since taking office in 2013, but he has left open the possibility of caucusing with the Republican Party in the future.
State Senator Eric Brakey ran unopposed for the Republican nomination.
Public school teacher and founder of UClass Zak Ringelstein ran unopposed for the Democratic nomination.
The election was conducted with ranked choice voting, as opposed to "First-past-the-post voting", after Maine voters passed a citizen referendum approving the change in 2016 and a June 2018 referendum sustaining the change.
King was easily re-elected with over 50% of the vote.
Maine Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Zak Ringelstein | 89,841 | 100.00 |
| Total votes | Total votes | Total votes | 89,841 | 100.00 |
Maine Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Eric Brakey | 59,853 | 100.00 |
| Total votes | Total votes | Total votes | 59,853 | 100.00 |
Maine general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Independent | Angus King (incumbent) | 344,575 | 54.31% | +1.42 |
| | Republican | Eric Brakey | 223,502 | 35.23% | +4.48 |
| | Democratic | Zak Ringelstein | 66,268 | 10.45% | –2.81 |
| | Write-in | Write-in | 64 | 0.01% | N/A |
| Total votes | Total votes | Total votes | 634,409 | 100.00% | |
| | Independent hold | Independent hold | Independent hold | Independent hold | Independent hold |

## Maryland

Two-term Democrat Ben Cardin was re-elected with 56% of the vote in 2012. He won the Democratic primary.
Tony Campbell, Evan Cronhardt, Nnabu Eze, Gerald Smith, and Blaine Taylor were seeking the Republican nomination, with Campbell winning.
Arvin Vohra, vice chairman of the Libertarian National Committee, sought the Libertarian Party nomination.
Independents Neal Simon and Edward Shlikas, and Michael B Puskar ran.
Cardin won re-election to a third term in office.
Maryland Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Ben Cardin (incumbent) | 477,441 | 80.28 |
| | Democratic | Chelsea Manning | 34,611 | 5.82 |
| | Democratic | Jerome Segal | 20,027 | 3.37 |
| | Democratic | Debbie Wilson | 18,953 | 3.19 |
| | Democratic | Marcia H. Morgan | 16,047 | 2.70 |
| | Democratic | Lih Young | 9,874 | 1.66 |
| | Democratic | Richard Vaughn | 9,480 | 1.59 |
| | Democratic | Erik Jetmir | 8,259 | 1.39 |
| Total votes | Total votes | Total votes | 594,692 | 100.00 |
Maryland Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Tony Campbell | 51,426 | 29.22 |
| | Republican | Chris Chaffee | 42,328 | 24.05 |
| | Republican | Christina J. Grigorian | 30,756 | 17.48 |
| | Republican | John Graziani | 15,435 | 8.77 |
| | Republican | Blaine Taylor | 8,848 | 5.03 |
| | Republican | Gerald I. Smith Jr. | 7,564 | 4.30 |
| | Republican | Brian Charles Vaeth | 5,411 | 3.07 |
| | Republican | Evan M. Cronhardt | 4,445 | 2.53 |
| | Republican | Bill Krehnbrink | 3,606 | 2.05 |
| | Republican | Nnabu Eze | 3,442 | 1.96 |
| | Republican | Albert Binyahmin Howard | 2,720 | 1.55 |
| Total votes | Total votes | Total votes | 175,981 | 100.00 |
Maryland general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Ben Cardin (incumbent) | 1,491,614 | 64.86% | +8.88 |
| | Republican | Tony Campbell | 697,017 | 30.31% | +3.98 |
| | Independent | Neal Simon | 85,964 | 3.74% | N/A |
| | Libertarian | Arvin Vohra | 22,943 | 1.00% | –0.22 |
| | Write-in | Write-in | 2,351 | 0.10% | ±0.00 |
| Total votes | Total votes | Total votes | 2,299,889 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Massachusetts

One-term Democrat Elizabeth Warren was elected with 54% of the vote in 2012. She ran for re-election.
State Representative Geoff Diehl, attorney and founder of Better for America, John Kingston and former Romney aide Beth Lindstrom, ran for the Republican nomination. Diehl won the Republican nomination.
Shiva Ayyadurai ran as an independent. Shiva started as in early 2017 as the first Republican in the race, but went independent in November 2017.
Warren defeated Diehl, winning a second term.
Massachusetts Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Elizabeth Warren (incumbent) | 590,835 | 98.08 |
| | Write-in | Write-in | 11,558 | 1.92 |
| Total votes | Total votes | Total votes | 602,393 | 100.00 |
Massachusetts Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Geoff Diehl | 144,043 | 55.15 |
| | Republican | John Kingston III | 69,636 | 26.66 |
| | Republican | Beth Joyce Lindstrom | 46,693 | 17.88 |
| | Write-in | Write-in | 798 | 0.31 |
| Total votes | Total votes | Total votes | 261,170 | 100.00 |
Massachusetts general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Elizabeth Warren (incumbent) | 1,633,371 | 60.34% | +6.60 |
| | Republican | Geoff Diehl | 979,210 | 36.17% | –10.02 |
| | Independent | Shiva Ayyadurai | 91,710 | 3.39% | N/A |
| | Write-in | Write-in | 2,799 | 0.10% | +0.03 |
| Total votes | Total votes | Total votes | 2,707,090 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Michigan

Three-term Democrat Debbie Stabenow was re-elected with 59% of the vote in 2012. She was renominated without Democratic opposition. On the Republican side, businessman John James won the nomination.
In the final months of the election, polls showed the race was beginning to narrow. Ultimately, Stabenow was re-elected, defeating James, with a majority of the vote.
Michigan Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Debbie Stabenow (incumbent) | 1,045,450 | 100.00 |
| Total votes | Total votes | Total votes | 1,045,450 | 100.00 |
Michigan Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | John James | 518,564 | 54.67 |
| | Republican | Sandy Pensler | 429,885 | 45.32 |
| | Write-in | Write-in | 57 | 0.01 |
| Total votes | Total votes | Total votes | 948,506 | 100.00 |
Michigan general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Debbie Stabenow (incumbent) | 2,214,478 | 52.26% | –6.54 |
| | Republican | John James | 1,938,818 | 45.76% | +7.78 |
| | Green | Marcia Squier | 40,204 | 0.95% | +0.35 |
| | Constitution | George Huffman III | 27,251 | 0.64% | +0.08 |
| | Natural Law | John Howard Wilhelm | 16,502 | 0.39% | +0.15 |
| | Write-in | Write-in | 18 | 0.00% | ±0.00 |
| Total votes | Total votes | Total votes | 4,237,271 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Minnesota
### Minnesota (regular)

Two-term Democrat Amy Klobuchar was re-elected with 65% of the vote in 2012. She ran for re-election.
State Representative Jim Newberger ran for the Republican nomination.
Klobuchar was easily re-elected.
Minnesota Democratic (DFL) primary :
| Party | Party | Candidate | Votes | % |
| | Democratic (DFL) | Amy Klobuchar (incumbent) | 557,306 | 95.70 |
| | Democratic (DFL) | Steve Carlson | 9,934 | 1.71 |
| | Democratic (DFL) | Stephen A. Emery | 7,047 | 1.21 |
| | Democratic (DFL) | David Robert Groves | 4,511 | 0.77 |
| | Democratic (DFL) | Leonard J. Richards | 3,552 | 0.61 |
| Total votes | Total votes | Total votes | 582,350 | 100.00 |
Minnesota Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Jim Newberger | 201,531 | 69.50 |
| | Republican | Merrill Anderson | 45,492 | 15.69 |
| | Republican | Rae Hart Anderon | 25,883 | 8.93 |
| | Republican | Rocky De La Fuente | 17,051 | 5.88 |
| Total votes | Total votes | Total votes | 289,957 | 100.00 |
Minnesota general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic (DFL) | Amy Klobuchar (incumbent) | 1,566,174 | 60.31% | –4.92 |
| | Republican | Jim Newberger | 940,437 | 36.21% | +5.68 |
| | Legal Marijuana Now | Dennis Schuller | 66,236 | 2.55% | N/A |
| | Green | Paula M. Overby | 23,101 | 0.89% | N/A |
| | Write-in | Write-in | 931 | 0.04% | –0.05 |
| Total votes | Total votes | Total votes | 2,596,879 | 100.00% | |
| | Democratic (DFL) hold | Democratic (DFL) hold | Democratic (DFL) hold | Democratic (DFL) hold | Democratic (DFL) hold |

### Minnesota (special)

Two-term Democrat Al Franken announced that he would resign in December 2017, following allegations of sexual harassment. Mark Dayton, Governor of Minnesota, appointed Lt. Gov. Tina Smith on January 2, 2018, as an interim Senator until the November 2018 election. She defeated primary challenger Richard Painter in the Democratic primary held on August 14.
Incumbent Tina Smith defeated Republican Karin Housley in the general election to finish the term ending January 3, 2021.
Minnesota Democratic (DFL) primary :
| Party | Party | Candidate | Votes | % |
| | Democratic (DFL) | Tina Smith (incumbent) | 433,705 | 76.06 |
| | Democratic (DFL) | Richard Painter | 78,193 | 13.71 |
| | Democratic (DFL) | Ali Chehem Ali | 18,897 | 3.31 |
| | Democratic (DFL) | Gregg A. Iverson | 17,825 | 3.13 |
| | Democratic (DFL) | Nick Leonard | 16,529 | 2.90 |
| | Democratic (DFL) | Christopher Lovell Seymore Sr. | 5,041 | 0.88 |
| Total votes | Total votes | Total votes | 570,190 | 100.00 |
Minnesota Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Karin Housley | 186,384 | 61.95 |
| | Republican | Bob Anderson | 107,102 | 35.60 |
| | Republican | Nikolay Nikolayevich Bey | 7,375 | 2.45 |
| Total votes | Total votes | Total votes | 300,861 | 100.00 |
Minnesota special election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic (DFL) | Tina Smith (incumbent) | 1,370,540 | 52.97% | –0.18 |
| | Republican | Karin Housley | 1,095,777 | 42.35% | –0.56 |
| | Legal Marijuana Now | Sarah Wellington | 95,614 | 3.70% | N/A |
| | Independent | Jerry Trooien | 24,324 | 0.94% | N/A |
| | Write-in | Write-in | 1,101 | 0.04% | ±0.00 |
| Total votes | Total votes | Total votes | 2,587,356 | 100.00% | |
| | Democratic (DFL) hold | Democratic (DFL) hold | Democratic (DFL) hold | Democratic (DFL) hold | Democratic (DFL) hold |

## Mississippi
### Mississippi (regular)

One-term Republican Roger Wicker won re-election with 57% of the vote in 2012. He was appointed in 2007 and won a special election in 2008 to serve the remainder of Trent Lott's term.
David Baria won the Democratic nomination in a run-off on June 26.
Wicker was easily re-elected.
Mississippi Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Roger Wicker (incumbent) | 130,118 | 82.79 |
| | Republican | Richard Boyanton | 27,052 | 17.21 |
| Total votes | Total votes | Total votes | 157,170 | 100.00 |
Mississippi Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Howard Sherman | 27,957 | 31.79 |
| | Democratic | David Baria | 27,244 | 30.98 |
| | Democratic | Omeria Scott | 21,278 | 24.20 |
| | Democratic | Victor G. Maurice Jr. | 4,361 | 4.96 |
| | Democratic | Jerome Garland | 4,266 | 4.85 |
| | Democratic | Jensen Bohren | 2,825 | 3.21 |
| Total votes | Total votes | Total votes | 87,931 | 100.00 |
Mississippi Democratic primary runoff :
| Party | Party | Candidate | Votes | % |
| | Democratic | David Baria | 44,156 | 58.64 |
| | Democratic | Howard Sherman | 31,149 | 41.36 |
| Total votes | Total votes | Total votes | 75,305 | 100.00 |
Mississippi general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Roger Wicker (incumbent) | 547,619 | 58.49% | +1.33 |
| | Democratic | David Baria | 369,567 | 39.47% | –1.08 |
| | Libertarian | Danny Bedwell | 12,981 | 1.39% | N/A |
| | Reform | Shawn O'Hara | 6,048 | 0.65% | –0.58 |
| Total votes | Total votes | Total votes | 936,215 | 100.00% | |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

### Mississippi (special)

Seven-term Republican Thad Cochran, who won re-election with 59.9% of the vote in 2014, announced that he would resign since April 1, 2018 for health reasons. Phil Bryant, Governor of Mississippi, announced on March 21, 2018, that he would appoint Mississippi Agriculture Commissioner Cindy Hyde-Smith to fill the vacancy. She ran in the special election.
On November 6, a nonpartisan jungle primary took place on the same day as the regularly scheduled U.S. Senate election for the seat currently held by Roger Wicker. Party affiliations were not printed on the ballot. As no candidate gained 50% of the votes, a runoff special election between the top two candidates - Hyde-Smith and former United States Secretary of Agriculture Mike Espy - was held on November 27, 2018. Hyde-Smith won the runoff election.
Democrat Tobey Bartee and Republican Chris McDaniel also contested the first round of the election.
Mississippi special election :
| Party | Party | Candidate | Votes | % |
| | Nonpartisan | Cindy Hyde-Smith (incumbent) | 389,995 | 41.25 |
| | Nonpartisan | Mike Espy | 386,742 | 40.90 |
| | Nonpartisan | Chris McDaniel | 154,878 | 16.38 |
| | Nonpartisan | Tobey Bernard Bartee | 13,852 | 1.47 |
| Total votes | Total votes | Total votes | 945,467 | 100.00 |
Mississippi special election runoff :
| Party | Party | Candidate | Votes | % | ±% |
| | Nonpartisan | Cindy Hyde-Smith (incumbent) | 486,769 | 53.63% | –6.27 |
| | Nonpartisan | Mike Espy | 420,819 | 46.37% | +8.48 |
| Total votes | Total votes | Total votes | 907,588 | 100.00% | |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

## Missouri

Two-term Democrat Claire McCaskill was re-elected with 55% of the vote in 2012. She was renominated.
Attorney General Josh Hawley won the Republican nomination. Japheth Campbell declared his candidacy for the Libertarian nomination.
Polls showed a close race for months leading up to the election. Hawley defeated McCaskill in the general election.
Missouri Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Claire McCaskill (incumbent) | 501,872 | 82.60 |
| | Democratic | Carla Wright | 41,126 | 6.77 |
| | Democratic | David Faust | 15,984 | 2.63 |
| | Democratic | John Hogan | 15,958 | 2.63 |
| | Democratic | Angelica Earl | 15,500 | 2.55 |
| | Democratic | Travis Gonzalez | 9,480 | 1.56 |
| | Democratic | Leonard Joseph Steinman II | 7,657 | 1.26 |
| Total votes | Total votes | Total votes | 607,577 | 100.00 |
Missouri Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Josh Hawley | 389,978 | 58.64 |
| | Republican | Tony Monetti | 64,834 | 9.75 |
| | Republican | Austin Petersen | 54,916 | 8.26 |
| | Republican | Kristi Nichols | 49,640 | 7.47 |
| | Republican | Christina Smith | 35,024 | 5.27 |
| | Republican | Ken Patterson | 19,579 | 2.94 |
| | Republican | Peter Pfeifer | 16,594 | 2.50 |
| | Republican | Courtland Sykes | 13,870 | 2.09 |
| | Republican | Fred Ryman | 8,781 | 1.32 |
| | Republican | Brian G. Hagg | 6,871 | 1.03 |
| | Republican | Bradley Krembs | 4,902 | 0.74 |
| Total votes | Total votes | Total votes | 664,889 | 100.00 |
Missouri general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Josh Hawley | 1,254,927 | 51.38% | +12.27 |
| | Democratic | Claire McCaskill (incumbent) | 1,112,935 | 45.57% | –9.24 |
| | Independent | Craig O'Dear | 34,398 | 1.41% | N/A |
| | Libertarian | Japheth Campbell | 27,316 | 1.12% | –4.95 |
| | Green | Jo Crain | 12,706 | 0.52% | N/A |
| | Write-in | Write-in | 7 | 0.00% | –0.01 |
| Total votes | Total votes | Total votes | 2,442,289 | 100.00% | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Montana

Two-term Democrat Jon Tester was re-elected with 49% of the vote in 2012. He won the Democratic nomination in the June 5 primary with no opposition.
State Auditor Matthew Rosendale won the Republican nomination in the June 5 primary. State Senator Albert Olszewski, former judge Russell Fagg, and Troy Downing also ran for the Republican nomination.
Tester was re-elected winning over 50% of the vote.
Montana Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jon Tester (incumbent) | 114,948 | 100.00 |
| | Write-in | Write-in | 5 | 0.00 |
| Total votes | Total votes | Total votes | 114,953 | 100.00 |
Montana Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Matt Rosendale | 51,859 | 33.82 |
| | Republican | Russell Fagg | 43,465 | 28.34 |
| | Republican | Troy Downing | 29,341 | 19.13 |
| | Republican | Albert Olszewski | 28,681 | 18.70 |
| | Write-in | Write-in | 9 | 0.01 |
| Total votes | Total votes | Total votes | 153,355 | 100.00 |
Montana general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jon Tester (incumbent) | 253,876 | 50.33% | +1.75 |
| | Republican | Matt Rosendale | 235,963 | 46.78% | +1.92 |
| | Libertarian | Rick Breckenridge | 14,545 | 2.88% | –3.68 |
| Total votes | Total votes | Total votes | 504,384 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Nebraska

One-term Republican Deb Fischer was elected with 58% of the vote in 2012. She ran for and won the Republican nomination in the May 15 primary. Other Republicans who ran include retired professor Jack Heidel, Todd Watson, and Dennis Frank Macek.
Lincoln City Councilwoman Jane Raybould ran for and won the Democratic nomination in the May 15 primary. Other Democrats who ran include Frank Svoboda, Chris Janicek, and Larry Marvin, who was a candidate in 2008, 2012, and 2014.
Jim Schultz ran for the Libertarian nomination.
Fischer was easily re-elected.
Nebraska Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Deb Fischer (incumbent) | 128,157 | 75.79 |
| | Republican | Todd F. Watson | 19,661 | 11.63 |
| | Republican | Jack Heidel | 9,413 | 5.57 |
| | Republican | Jeffrey Lynn Stein | 6,380 | 3.77 |
| | Republican | Dennis Frank Macek | 5,483 | 3.24 |
| Total votes | Total votes | Total votes | 169,094 | 100.00 |
Nebraska Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jane Raybould | 59,067 | 63.68 |
| | Democratic | Chris Janicek | 18,752 | 20.22 |
| | Democratic | Frank B. Svoboda | 10,548 | 11.37 |
| | Democratic | Larry Marvin | 4,393 | 4.74 |
| Total votes | Total votes | Total votes | 92,760 | 100.00 |
Nebraska general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Deb Fischer (incumbent) | 403,151 | 57.69% | –0.08 |
| | Democratic | Jane Raybould | 269,917 | 38.62% | –3.61 |
| | Libertarian | Jim Schultz | 25,349 | 3.63% | N/A |
| | Write-in | Write-in | 466 | 0.07% | N/A |
| Total votes | Total votes | Total votes | 698,883 | 100.00% | |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

## Nevada

Incumbent Republican Dean Heller was the Republican nominee. He was appointed to the seat in 2011 and then elected with 46% of the vote in 2012. Heller considered running for governor, but chose to seek re-election.
Nevada was the only state in the mid-term elections that had an incumbent Republican senator in a state that Hillary Clinton had won in 2016.
Representative Jacky Rosen is the Democratic nominee.
Rosen defeated Heller in the general election, making Heller the only Republican incumbent to lose re-election in 2018.
Nevada Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Dean Heller (incumbent) | 99,509 | 69.97 |
| | Republican | Tom Heck | 26,296 | 18.49 |
| | None of These Candidates | None of These Candidates | 5,978 | 4.20 |
| | Republican | Sherry Brooks | 5,145 | 3.62 |
| | Republican | Sarah Gazala | 4,011 | 2.82 |
| | Republican | Vic Harrell | 1,282 | 0.90 |
| Total votes | Total votes | Total votes | 142,221 | 100.00 |
Nevada Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jacky Rosen | 110,567 | 77.11 |
| | None of These Candidates | None of These Candidates | 10,078 | 7.03 |
| | Democratic | David Drew Knight | 6,346 | 4.43 |
| | Democratic | Allen Rheinhart | 4,782 | 3.33 |
| | Democratic | Jesse Sbaih | 4,540 | 3.17 |
| | Democratic | Sujeet Mahendra | 3,835 | 2.67 |
| | Democratic | Danny Burleigh | 3,244 | 2.26 |
| Total votes | Total votes | Total votes | 143,392 | 100.00 |
Nevada general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jacky Rosen | 490,071 | 50.41% | +5.70 |
| | Republican | Dean Heller (incumbent) | 441,202 | 45.38% | –0.49 |
| | None of These Candidates | None of These Candidates | 15,303 | 1.57% | –2.97 |
| | Independent | Barry Michaels | 9,269 | 0.95% | N/A |
| | Libertarian | Tim Hagan | 9,196 | 0.95% | N/A |
| | Independent American | Kamau A. Bakari | 7,091 | 0.73% | –4.16 |
| Total votes | Total votes | Total votes | 972,132 | 100.00% | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## New Jersey

Republican Bob Hugin was nominated to face two-term Democrat Bob Menendez, who was re-elected with 59% of the vote in 2012. Menendez was originally appointed to the seat in January 2006. He ran for re-election, despite recent scandals that plagued his campaign.
Hugin self-funded most of his campaign. Ultimately, Menendez was re-elected with nearly 54% of the vote.
New Jersey Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bob Menendez (incumbent) | 262,477 | 62.28 |
| | Democratic | Lisa A. McCormick | 158,998 | 37.72 |
| Total votes | Total votes | Total votes | 421,475 | 100.00 |
New Jersey Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Bob Hugin | 168,052 | 75.13 |
| | Republican | Brian D. Goldberg | 55,624 | 24.87 |
| Total votes | Total votes | Total votes | 223,676 | 100.00 |
New Jersey general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Bob Menendez (incumbent) | 1,711,654 | 54.01% | –4.86 |
| | Republican | Bob Hugin | 1,357,355 | 42.83% | +3.46 |
| | Green | Madelyn R. Hoffman | 25,150 | 0.79% | +0.32 |
| | Libertarian | Murray Sabrin | 21,212 | 0.67% | +0.17 |
| | Independent | Natalie Lynn Rivera | 19,897 | 0.63% | N/A |
| | Independent | Tricia Flanagan | 16,101 | 0.51% | N/A |
| | Independent | Kevin Kimple | 9,087 | 0.29% | N/A |
| | Independent | Hank Schroeder | 8,854 | 0.28% | N/A |
| Total votes | Total votes | Total votes | 3,169,310 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## New Mexico

One-term Democrat Martin Heinrich was elected with 51% of the vote in 2012. He ran. Mick Rich won the Republican nomination unopposed.
Aubrey Dunn Jr., New Mexico Commissioner of Public Lands and otherwise the first Libertarian to ever hold statewide elected office in history, announced his run for the seat, but stepped aside in August to allow former Governor of New Mexico, Gary Johnson's candidacy.
Heinrich was easily re-elected, defeating Rich and Johnson.
New Mexico Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Martin Heinrich (incumbent) | 152,145 | 100.00 |
| Total votes | Total votes | Total votes | 152,145 | 100.00 |
New Mexico Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Mick Rich | 67,502 | 100.00 |
| Total votes | Total votes | Total votes | 67,502 | 100.00 |
New Mexico Libertarian primary :
| Party | Party | Candidate | Votes | % |
| | Libertarian | Aubrey Dunn Jr. | 623 | 100.00 |
| Total votes | Total votes | Total votes | 623 | 100.00 |
New Mexico general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Martin Heinrich (incumbent) | 376,998 | 54.09% | +3.08 |
| | Republican | Mick Rich | 212,813 | 30.53% | –14.75 |
| | Libertarian | Gary Johnson | 107,201 | 15.38% | N/A |
| Total votes | Total votes | Total votes | 697,012 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## New York

One-term Democrat Kirsten Gillibrand was elected with 72% of the vote in 2012. She had previously been appointed to the seat in 2009 and won a special election to remain in office in 2010. She ran.
Private equity executive Chele Chiavacci Farley has been nominated for U.S. Senate by the Republican and Conservative Parties.
Gillibrand was elected to a second term.
New York general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Kirsten Gillibrand | 3,755,489 | 61.98% | –4.40 |
| | Working Families | Kirsten Gillibrand | 160,128 | 2.64% | –1.12 |
| | Independence | Kirsten Gillibrand | 99,325 | 1.64% | –0.43 |
| | Women's Equality | Kirsten Gillibrand | 41,989 | 0.69% | N/A |
| | Total | Kirsten Gillibrand (incumbent) | 4,056,931 | 66.96% | –5.25 |
| | Republican | Chele Farley | 1,730,439 | 28.56% | +5.83 |
| | Conservative | Chele Farley | 246,171 | 4.06% | +0.45 |
| | Reform | Chele Farley | 21,610 | 0.36% | N/A |
| | Total | Chele Farley | 1,998,220 | 32.98% | +6.64 |
| | Write-in | Write-in | 3,872 | 0.06% | N/A |
| Total votes | Total votes | Total votes | 6,059,023 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## North Dakota

One-term Democrat Heidi Heitkamp was elected with 50% of the vote in 2012. She won the Democratic nomination unopposed.
Representative Kevin Cramer won the Republican nomination in the June 12 primary. Former Niagara, North Dakota Mayor Thomas O'Neill also ran for the Republican nomination.
Heitkamp was continuously behind in the polls leading up to the election, and Heitkamp ended up losing to Cramer by 11%.
North Dakota Democratic-NPL primary :
| Party | Party | Candidate | Votes | % |
| | Democratic–NPL | Heidi Heitkamp (incumbent) | 36,729 | 99.58 |
| | Write-in | Write-in | 154 | 0.42 |
| Total votes | Total votes | Total votes | 36,883 | 100.00 |
North Dakota Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Kevin Cramer | 61,529 | 87.73 |
| | Republican | Thomas O'Neill | 8,509 | 12.13 |
| | Write-in | Write-in | 95 | 0.14 |
| Total votes | Total votes | Total votes | 70,133 | 100.00 |
North Dakota general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Kevin Cramer | 179,720 | 55.11% | +5.79 |
| | Democratic–NPL | Heidi Heitkamp (incumbent) | 144,376 | 44.27% | –5.97 |
| | Write-in | Write-in | 2,042 | 0.63% | +0.19 |
| Total votes | Total votes | Total votes | 326,138 | 100.00% | |
| | Republican gain from Democratic–NPL | Republican gain from Democratic–NPL | Republican gain from Democratic–NPL | Republican gain from Democratic–NPL | Republican gain from Democratic–NPL |

## Ohio

Two-term Democrat Sherrod Brown was re-elected with 51% of the vote in 2012. He ran and was unopposed in Democratic primary.
U.S. Representative Jim Renacci ran for and won the Republican nomination in the May 8 primary. Other Republicans who ran include investment banker Michael Gibbons, businesswoman Melissa Ackison, Dan Kiley, and Don Elijah Eckhart.
Brown won re-election, defeating Renacci. Brown was the only non-judicial statewide Democrat in Ohio to win in 2018.
Ohio Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Sherrod Brown (incumbent) | 613,373 | 100.00 |
| Total votes | Total votes | Total votes | 613,373 | 100.00 |
Ohio Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Jim Renacci | 363,622 | 47.34 |
| | Republican | Mike Gibbons | 243,426 | 31.69 |
| | Republican | Melissa Ackison | 100,543 | 13.09 |
| | Republican | Dan Kiley | 30,684 | 3.99 |
| | Republican | Don Elijah Eckhart | 29,796 | 3.88 |
| | Write-in | Write-in | 78 | 0.01 |
| Total votes | Total votes | Total votes | 768,149 | 100.00 |
Ohio general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Sherrod Brown (incumbent) | 2,355,924 | 53.41% | +2.70% |
| | Republican | Jim Renacci | 2,053,963 | 46.57% | +1.87% |
| | Write-in | Write-in | 1,012 | 0.02% | N/A |
| Total votes | Total votes | Total votes | 4,410,898 | 100.00% | N/A |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Pennsylvania

Two-term Democrat Bob Casey Jr. was re-elected with 54% of the vote in 2012. He ran and won the Democratic primary unopposed.
U.S. Representative Lou Barletta ran for and won the Republican nomination in the May 15 primary. Jim Christiana also ran for the Republican nomination.
Casey was easily re-elected.
Pennsylvania Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bob Casey Jr. (incumbent) | 752,008 | 99.13 |
| | Write-in | Write-in | 6,584 | 0.87 |
| Total votes | Total votes | Total votes | 758,592 | 100.00 |
Pennsylvania Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Lou Barletta | 433,312 | 62.80 |
| | Republican | Jim Christiana | 254,118 | 36.83 |
| | Write-in | Write-in | 2,553 | 0.37 |
| Total votes | Total votes | Total votes | 689,983 | 100.00 |
Pennsylvania general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Bob Casey Jr. (incumbent) | 2,792,437 | 55.73% | +2.04 |
| | Republican | Lou Barletta | 2,134,848 | 42.60% | –1.99 |
| | Libertarian | Dale Kerns | 50,907 | 1.02% | –0.70 |
| | Green | Neal Gale | 31,208 | 0.62% | N/A |
| | Write-in | Write-in | 1,568 | 0.03% | N/A |
| Total votes | Total votes | Total votes | 5,010,968 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Rhode Island

Two-term Democrat Sheldon Whitehouse was re-elected with 64% of the vote in 2012. He ran.
Former Rhode Island Supreme Court Associate Justice Robert Flanders was the Republican nominee.
Whitehouse was elected to a third term by a wide margin.
Rhode Island Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Sheldon Whitehouse (incumbent) | 89,140 | 76.79 |
| | Democratic | Patricia Fontes | 26,947 | 23.21 |
| Total votes | Total votes | Total votes | 116,087 | 100.00 |
Rhode Island Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Robert Flanders | 26,543 | 87.70 |
| | Republican | Rocky De La Fuente | 3,722 | 12.30 |
| Total votes | Total votes | Total votes | 30,265 | 100.00 |
Rhode Island general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Sheldon Whitehouse (incumbent) | 231,477 | 61.44% | –3.37 |
| | Republican | Robert Flanders | 144,421 | 38.33% | +3.36 |
| | Write-in | Write-in | 840 | 0.22% | ±0.00 |
| Total votes | Total votes | Total votes | 376,738 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Tennessee

Two-term Republican Bob Corker was re-elected with 65% of the vote in 2012. Senator Corker filed his Statement of Candidacy with the Secretary of the U.S. Senate to run for re-election, but on September 26, 2017, Senator Corker announced his intent to retire.
Aaron Pettigrew and Republican U.S. Representative Marsha Blackburn ran for the Republican nomination. Marsha Blackburn became the Republican nominee.
Former Tennessee Governor Phil Bredesen became the Democratic nominee.
Tennessee Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Marsha Blackburn | 613,513 | 84.48 |
| | Republican | Aaron Pettigrew | 112,705 | 15.52 |
| | Write-in | Write-in | 13 | 0.00 |
| Total votes | Total votes | Total votes | 726,231 | 100.00 |
Tennessee Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Phil Bredesen | 349,718 | 91.51 |
| | Democratic | Gary Davis | 20,170 | 5.28 |
| | Democratic | John Wolfe Jr. | 12,269 | 3.21 |
| Total votes | Total votes | Total votes | 382,157 | 100.00 |
Tennessee general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Marsha Blackburn | 1,227,483 | 54.71% | −10.18% |
| | Democratic | Phil Bredesen | 985,450 | 43.92% | +13.51% |
| | Independent | Trudy Austin | 9,455 | 0.42% | N/A |
| | Independent | Dean Hill | 8,717 | 0.39% | N/A |
| | Independent | Kris L. Todd | 5,084 | 0.23% | N/A |
| | Independent | John Carico | 3,398 | 0.15% | N/A |
| | Independent | Breton Phillips | 2,226 | 0.10% | N/A |
| | Independent | Kevin Lee McCants | 1,927 | 0.09% | N/A |
| Total votes | Total votes | Total votes | 2,243,740 | 100.00% | N/A |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

## Texas

One-term Republican Ted Cruz was elected with 57% of the vote in 2012. He overwhelmingly won the Republican primary on March 6, 2018. Television producer Bruce Jacobson, Houston energy attorney Stefano de Stefano, former mayor of La Marque Geraldine Sam, Mary Miller, and Thomas Dillingham were Cruz's opponents.
U.S. Representative Beto O'Rourke won the Democratic nomination on March 6, 2018. Other Democrats who ran include Irasema Ramirez Hernandez and Edward Kimbrough.
Nurse Carl Bible ran as an independent. Bob McNeil ran as the candidate of the American Citizen Party. Neal Dikeman was the Libertarian nominee.
O'Rourke ran a strong campaign, creating a close race in what has traditionally been a Republican stronghold. Nevertheless, Cruz was narrowly re-elected to a second term.
Texas Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Ted Cruz (incumbent) | 1,322,724 | 85.36 |
| | Republican | Mary Miller | 94,715 | 6.11 |
| | Republican | Bruce Jacobson Jr. | 64,791 | 4.18 |
| | Republican | Stefano de Stefano | 44,456 | 2.87 |
| | Republican | Geraldine Sam | 22,887 | 1.48 |
| Total votes | Total votes | Total votes | 1,549,573 | 100.00 |
Texas Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Beto O'Rourke | 644,632 | 61.81 |
| | Democratic | Sema Hernandez | 247,424 | 23.72 |
| | Democratic | Edward Kimbrough | 150,858 | 14.47 |
| Total votes | Total votes | Total votes | 1,042,914 | 100.00 |
Texas general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Ted Cruz (incumbent) | 4,260,553 | 50.89% | –5.57 |
| | Democratic | Beto O'Rourke | 4,045,632 | 48.33% | +7.71 |
| | Libertarian | Neal Dikeman | 65,470 | 0.78% | –1.28 |
| Total votes | Total votes | Total votes | 8,371,655 | 100.00% | |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

## Utah

Seven-term Republican Orrin Hatch was re-elected with 65% of the vote in 2012. Hatch was the President pro tempore of the United States Senate, as well as the second most-senior Senator. Before the 2012 election, Hatch said that he would retire at the end of his seventh term if he was re-elected. Hatch initially announced his re-election campaign on March 9, 2017, but later announced his plans to retire on January 2, 2018. Former 2012 Republican presidential nominee Mitt Romney was running for the seat.
Professor James Singer was running for the Democratic nomination, but he dropped out and endorsed Salt Lake County Councilwoman Jenny Wilson, who made her Senate bid official on July 17, 2017. Danny Drew also was running, but dropped out and endorsed Jenny Wilson. Mitchell Kent Vice was defeated for the Democratic nomination by Wilson.
Mitt Romney was easily elected, defeating Wilson.
Utah Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Mitt Romney | 240,021 | 71.27 |
| | Republican | Mike Kennedy | 96,771 | 28.73 |
| Total votes | Total votes | Total votes | 336,792 | 100.00 |
Utah general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Mitt Romney | 665,215 | 62.59% | –2.72 |
| | Democratic | Jenny Wilson | 328,541 | 30.91% | +0.93 |
| | Constitution | Tim Aalders | 28,774 | 2.71% | –0.46 |
| | Libertarian | Craig Bowden | 27,607 | 2.60% | N/A |
| | Independent American | Reed McCandless | 12,708 | 1.20% | N/A |
| | Write-in | Write-in | 52 | 0.00% | ±0.00 |
| Total votes | Total votes | Total votes | 1,062,897 | 100.00% | |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |

## Vermont

Two-term Independent Senator Bernie Sanders was re-elected with 71% of the vote in 2012. Sanders, one of two independent members of Congress, has caucused with the Democratic Party since taking office in 2007. In November 2015, Sanders announced his plans to run as a Democrat, rather than an independent, in all future elections. He won the nomination easily.
Sanders easily won election to a third term.
Vermont Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bernie Sanders (incumbent) | 63,683 | 94.02 |
| | Democratic | Folsade Adeluola | 3,766 | 5.56 |
| | Write-in | Write-in | 281 | 0.41 |
| Total votes | Total votes | Total votes | 67,730 | 100.00 |
Vermont Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | H. Brooke Paige | 9,805 | 37.37 |
| | Republican | Lawrence Zupan | 9,383 | 35.86 |
| | Republican | Jasdeep Pannu | 4,527 | 17.30 |
| | Write-in | Bernie Sanders (incumbent) | 1,081 | 4.13 |
| | Republican | Rocky De La Fuente | 1,057 | 4.04 |
| | Write-in | Write-in | 314 | 1.20 |
| Total votes | Total votes | Total votes | 26,167 | 100.00 |
Vermont general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Independent | Bernie Sanders (incumbent) | 183,649 | 67.36% | –3.64 |
| | Republican | Lawrence Zupan | 74,815 | 27.44% | +2.54 |
| | Independent | Brad Peacock | 3,665 | 1.34% | N/A |
| | Independent | Russell Beste | 2,763 | 1.01% | N/A |
| | Independent | Edward Gilbert Jr. | 2,244 | 0.82% | N/A |
| | Independent | Folasade Adeluola | 1,979 | 0.73% | N/A |
| | Liberty Union | Reid Kane | 1,171 | 0.43% | –0.43 |
| | Independent | Jon Svitavsky | 1,130 | 0.41% | N/A |
| | Independent | Bruce Busa | 914 | 0.34% | N/A |
| | Write-in | Write-in | 294 | 0.11% | +0.03 |
| Total votes | Total votes | Total votes | 272,624 | 100.00% | |
| | Independent hold | Independent hold | Independent hold | Independent hold | Independent hold |

## Virginia

One-term Democrat Tim Kaine was elected with 53% of the vote in 2012. He was re-nominated unopposed. Prince William County Supervisor Corey Stewart was the Republican nominee. Matt Waters was the Libertarian nominee. Kaine defeated Stewart with 57% of the vote. Stewart received 41% of the vote.
Virginia Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Corey Stewart | 136,610 | 44.86 |
| | Republican | Nick Freitas | 131,321 | 43.12 |
| | Republican | E. W. Jackson | 36,508 | 11.99 |
| | Write-in | Write-in | 79 | 0.03 |
| Total votes | Total votes | Total votes | 304,518 | 100.00 |
Virginia general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Tim Kaine (incumbent) | 1,910,370 | 57.00% | +4.17 |
| | Republican | Corey Stewart | 1,374,313 | 41.00% | –5.92 |
| | Libertarian | Matt Waters | 61,565 | 1.84% | N/A |
| | Write-in | Write-in | 5,509 | 0.16% | –0.09 |
| Total votes | Total votes | Total votes | 3,351,757 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Washington

Three-term Democrat Maria Cantwell was re-elected with 61% of the vote in 2012. She ran.
Washington holds non-partisan blanket primaries, in which the top two finishers advance to the general election regardless of party. Cantwell and former state Republican Party chair Susan Hutchison faced each other in November.
Cantwell won re-election by a large margin.
Washington blanket primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Maria Cantwell (incumbent) | 929,961 | 54.68 |
| | Republican | Susan Hutchison | 413,317 | 24.30 |
| | Republican | Keith Swank | 39,818 | 2.34 |
| | Republican | Joey Gibson | 38,676 | 2.27 |
| | Democratic | Clint Tannehill | 35,770 | 2.10 |
| | Republican | Dave Bryant | 33,962 | 2.00 |
| | Republican | Art Coday | 30,654 | 1.80 |
| | Independent | Jennifer Ferguson | 25,224 | 1.48 |
| | Republican | Tim Owen | 23,167 | 1.36 |
| | Republican | Matt Hawkins | 13,324 | 0.78 |
| | Democratic | Don Rivers | 12,634 | 0.74 |
| | Libertarian | Mike Luke | 12,302 | 0.72 |
| | Republican | Glen Stockwell | 11,611 | 0.68 |
| | Independent | Thor Amundson | 9,393 | 0.55 |
| | Democratic | Mohammad Said | 8,649 | 0.51 |
| | Republican | Matthew Heines | 7,737 | 0.45 |
| | Freedom Socialist | Steve Hoffman | 7,390 | 0.43 |
| | Republican | Goodspaceguy | 7,057 | 0.41 |
| | Republican | John Orlinski | 6,905 | 0.41 |
| | Independent | Dave Strider | 6,821 | 0.40 |
| | Republican | Rocky De La Fuente | 5,724 | 0.34 |
| | Green | James Robert Deal | 3,849 | 0.23 |
| | Independent | Sam Wright | 3,761 | 0.22 |
| | Independent | Brad Chase | 2,655 | 0.16 |
| | Democratic | George Kalberer | 2,448 | 0.14 |
| | Independent | Charlie Jackson | 2,411 | 0.14 |
| | Republican | RC Smith | 2,238 | 0.13 |
| | Independent | Jon Butler | 2,016 | 0.12 |
| | Independent | Alex Tsimerman | 1,366 | 0.08 |
| Total votes | Total votes | Total votes | 1,700,840 | 100.00 |
Washington general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Maria Cantwell (incumbent) | 1,803,364 | 58.43% | –2.02 |
| | Republican | Susan Hutchison | 1,282,804 | 41.57% | +2.02 |
| Total votes | Total votes | Total votes | 3,086,168 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## West Virginia

One-term Democrat Joe Manchin was elected with 61% of the vote in 2012. He originally won the seat in a 2010 special election. Manchin ran for re-election and won the May 8 Democratic primary. Environmental activist Paula Jean Swearengin, also ran for the Democratic nomination.
West Virginia Attorney General Patrick Morrisey received the Republican nomination in the May 8 primary. Representative Evan Jenkins, coal miner Bo Copley, Jack Newbrough, Don Blankenship, and Tom Willis ran for the Republican nomination.
Despite recent Republican successes in West Virginia, Manchin was able to win re-election to a second term.
West Virginia Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Joe Manchin (incumbent) | 112,658 | 69.86 |
| | Democratic | Paula Jean Swearengin | 48,594 | 30.14 |
| Total votes | Total votes | Total votes | 161,252 | 100.00 |
West Virginia Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Patrick Morrisey | 48,007 | 34.90 |
| | Republican | Evan Jenkins | 40,185 | 29.21 |
| | Republican | Don Blankenship | 27,478 | 19.97 |
| | Republican | Tom Willis | 13,540 | 9.84 |
| | Republican | Bo Copley | 4,248 | 3.09 |
| | Republican | Jack Newbrough | 4,115 | 2.99 |
| Total votes | Total votes | Total votes | 137,573 | 100.00 |
West Virginia general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Joe Manchin (incumbent) | 290,510 | 49.57% | –11.00 |
| | Republican | Patrick Morrisey | 271,113 | 46.26% | +9.79 |
| | Libertarian | Rusty Hollen | 24,411 | 4.17% | N/A |
| Total votes | Total votes | Total votes | 586,034 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Wisconsin

One-term Democrat Tammy Baldwin was elected with 51% of the vote in 2012. She ran.
State Senator Leah Vukmir and businessman and member of Wisconsin Board of Veterans Affairs Kevin Nicholson ran for the Republican nomination, with Vukmir proceeding to the general election.
Baldwin was re-elected with over 55% of the vote.
Wisconsin Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Tammy Baldwin (incumbent) | 510,812 | 99.64 |
| | Write-in | Write-in | 1,848 | 0.36 |
| Total votes | Total votes | Total votes | 512,660 | 100.00 |
Wisconsin Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | Leah Vukmir | 217,230 | 48.90 |
| | Republican | Kevin Nicholson | 191,276 | 43.06 |
| | Republican | George Lucia | 18,786 | 4.23 |
| | Republican | Griffin Jones | 8,699 | 1.96 |
| | Republican | Charles Barman | 7,959 | 1.79 |
| | Write-in | Write-in | 303 | 0.07 |
| Total votes | Total votes | Total votes | 444,253 | 100.00 |
Wisconsin general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Tammy Baldwin (incumbent) | 1,472,914 | 55.36% | +3.95 |
| | Republican | Leah Vukmir | 1,184,885 | 44.53% | –1.33 |
| | Write-in | Write-in | 2,964 | 0.11% | ±0.00 |
| Total votes | Total votes | Total votes | 2,660,763 | 100.00% | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Wyoming

One-term Republican John Barrasso was elected with 76% of the vote in 2012. Barrasso was appointed to the seat in 2007 and won a special election in 2008. He ran.
Gary Trauner, a Jackson Hole businessman and U.S. House candidate in 2006 and 2008, was the Democratic nominee.
Barrasso was easily elected to a second term, defeating Trauner.
Wyoming Republican primary :
| Party | Party | Candidate | Votes | % |
| | Republican | John Barrasso (incumbent) | 74,292 | 64.76 |
| | Republican | Dave Dodson | 32,647 | 28.46 |
| | Republican | John Holtz | 2,981 | 2.60 |
| | Republican | Charlie Hardy | 2,377 | 2.07 |
| | Republican | Rocky De La Fuente | 1,280 | 1.12 |
| | Republican | Anthony Van Risseghem | 870 | 0.76 |
| | Write-in | Write-in | 267 | 0.23 |
| Total votes | Total votes | Total votes | 114,714 | 100.00 |
Wyoming Democratic primary :
| Party | Party | Candidate | Votes | % |
| | Democratic | Gary Trauner | 17,562 | 98.90 |
| | Write-in | Write-in | 195 | 1.10 |
| Total votes | Total votes | Total votes | 17,757 | 100.00 |
Wyoming general election :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | John Barrasso (incumbent) | 136,210 | 66.96% | –8.70 |
| | Democratic | Gary Trauner | 61,227 | 30.10% | +8.45 |
| | Libertarian | Joseph Porambo | 5,658 | 2.78% | N/A |
| | Write-in | Write-in | 325 | 0.16% | –0.01 |
| Total votes | Total votes | Total votes | 203,420 | 100.00% | |
| | Republican hold | Republican hold | Republican hold | Republican hold | Republican hold |