# 1988 United States Senate elections

The 1988 United States Senate elections were elections for the United States Senate. Held on November 8, 1988, the 33 seats of Class 1 were contested in regular elections. In spite of the Republican victory by George H. W. Bush in the presidential election, the Democrats gained a net of 1 seat in the Senate. 7 seats changed parties, with 4 incumbents being defeated. The Democratic majority in the Senate increased by one to 55–45.
This is the last Senate election cycle in which California voted for a Republican, and the last in which Texas and Maine voted for a Democrat, and the last time Arizona voted for a Democrat until 2018. This would also be the last Senate election cycle until 1998 to not have at least one special election during that cycle.
This is also the last Senate election cycle in which no woman was elected to the Senate from either party as all of the winners were men.

## Results summary

Summary of the 1988 United States Senate election results
| 55 | 45 |
| Democratic | Republican |
| Parties | Parties | | | | | | Total |
| Parties | Parties | Democratic | Republican | Libertarian | Conservative | Other | Total |
| Last elections (1986) | Last elections (1986) | 55 | 45 | 0 | 0 | 0 | 100 |
| Before these elections | Before these elections | 54 | 46 | 0 | 0 | 0 | 100 |
| Not up | Not up | 36 | 31 | — | — | — | 67 |
| Up Class 1 (1982→1988) | Up Class 1 (1982→1988) | 18 | 15 | — | — | — | 33 |
| Incumbent retired | Incumbent retired | 3 | 3 | — | — | — | 6 |
| | Held by same party | 1 | 2 | — | — | — | 3 |
| | Replaced by other party | 1 Republican replaced by 1 Democrat 2 Democrats replaced by 2 Republicans | 1 Republican replaced by 1 Democrat 2 Democrats replaced by 2 Republicans | — | — | — | 3 |
| | Result | 2 | 4 | — | — | — | 6 |
| Incumbent ran | Incumbent ran | 15 | 12 | — | — | — | 27 |
| | Won re-election | 14 | 9 | — | — | — | 23 |
| | Lost re-election | 3 Republicans replaced by 3 Democrats 1 Democrat replaced by 1 Republican | 3 Republicans replaced by 3 Democrats 1 Democrat replaced by 1 Republican | — | — | — | 4 |
| | Lost renomination, but held by same party | 0 | 0 | — | — | — | 0 |
| | Result | 17 | 10 | — | — | — | 27 |
| Total elected | Total elected | 19 | 14 | — | — | — | 33 |
| Net gain/loss | Net gain/loss | 1 | 1 | | | | 1 |
| Nationwide vote | Nationwide vote | 35,137,786 | 31,151,251 | 268,053 | 189,226 | 677,928 | 67,424,244 |
| | Share | 52.11% | 46.20% | 0.40% | 0.28% | 1.01% | 100% |
| Result | Result | 55 | 45 | 0 | 0 | 0 | 100 |
Source: Clerk of the United States House of Representatives. "Statistics of the Presidential and Congressional Election of November 8, 1988" (PDF). U.S. Government Printing Office. Retrieved July 2, 2014.

## Gains and losses
### Retirements

Three Republicans and three Democrats retired instead of seeking re-election.
| State | Senator | Replaced by |
| Florida | Lawton Chiles | Connie Mack III |
| Mississippi | John C. Stennis | Trent Lott |
| Vermont | Robert Stafford | Jim Jeffords |
| Virginia | Paul Trible | Chuck Robb |
| Washington | Daniel J. Evans | Slade Gorton |
| Wisconsin | William Proxmire | Herb Kohl |

### Defeats

Three Republicans and one Democrat sought re-election but lost in the general election.
| State | Senator | Replaced by |
| Connecticut | Lowell Weicker | Joe Lieberman |
| Montana | John Melcher | Conrad Burns |
| Nebraska | David Karnes | Bob Kerrey |
| Nevada | Chic Hecht | Richard Bryan |

### Post-election changes

One Republican resigned on January 3, 1989, while one Democrat died on May 16, 1990. Initially, they were replaced by appointees.
| State | Senator | Replaced by |
| Hawaii (Class 1) | Spark Matsunaga | Daniel Akaka |
| Indiana (Class 3) | Dan Quayle | Dan Coats |

## 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$_{40}$ Maine Ran | D$_{39}$ Hawaii Ran | D$_{38}$ Fla. Retired | D$_{37}$ Ariz. Ran | D$_{36}$ | D$_{35}$ | D$_{34}$ | D$_{33}$ | D$_{32}$ | D$_{31}$ |
| D$_{41}$ Md. Ran | D$_{42}$ Mass. Ran | D$_{43}$ Mich. Ran | D$_{44}$ Miss. Retired | D$_{45}$ Mont. Ran | D$_{46}$ N.J. Ran | D$_{47}$ N.M. Ran | D$_{48}$ N.Y. Ran | D$_{49}$ N.D. Ran | D$_{50}$ Ohio Ran |
| Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | D$_{51}$ Tenn. Ran |
| R$_{41}$ R.I. Ran | R$_{42}$ Utah Ran | R$_{43}$ Vt. Retired | R$_{44}$ Va. Retired | R$_{45}$ Wash. Retired | R$_{46}$ Wyo. Ran | D$_{54}$ Wis. Retired | D$_{53}$ W.Va. Ran | D$_{52}$ Texas Ran | D$_{51}$ Tenn. Ran |
| R$_{40}$ Pa. Ran | R$_{39}$ Nev. Ran | R$_{38}$ Neb. Ran | R$_{37}$ Mo. Ran | R$_{36}$ Minn. Ran | R$_{35}$ Ind. Ran | R$_{34}$ Del. Ran | R$_{33}$ Conn. Ran | R$_{32}$ Calif. Ran | 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

| 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$_{40}$ Md. Re-elected | D$_{39}$ Maine Re-elected | D$_{38}$ Hawaii Re-elected | D$_{37}$ Ariz. Re-elected | D$_{36}$ | D$_{35}$ | D$_{34}$ | D$_{33}$ | D$_{32}$ | D$_{31}$ |
| D$_{41}$ Mass. Re-elected | D$_{42}$ Mich. Re-elected | D$_{43}$ N.J. Re-elected | D$_{44}$ N.M. Re-elected | D$_{45}$ N.Y. Re-elected | D$_{46}$ N.D. Re-elected | D$_{47}$ Ohio Re-elected | D$_{48}$ Tenn. Re-elected | D$_{49}$ Texas Re-elected | D$_{50}$ W.Va. Re-elected |
| Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | D$_{51}$ Wis. Hold |
| R$_{41}$ Wash. Hold | R$_{42}$ Wyo. Re-elected | R$_{43}$ Fla. Gain | R$_{44}$ Miss. Gain | R$_{45}$ Mont. Gain | D$_{55}$ Va. Gain | D$_{54}$ Nev. Gain | D$_{53}$ Neb. Gain | D$_{52}$ Conn. Gain | D$_{51}$ Wis. Hold |
| R$_{40}$ Vt. Hold | R$_{39}$ Utah Re-elected | R$_{38}$ R.I. Re-elected | R$_{37}$ Pa. Re-elected | R$_{36}$ Mo. Re-elected | R$_{35}$ Minn. Re-elected | R$_{34}$ Ind. Re-elected | R$_{33}$ Del. Re-elected | R$_{32}$ Calif. Re-elected | 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 |

## Race summary
### Special elections

There were no special elections in 1988.

### Elections leading to the next Congress

In these general elections, the winners were elected for the term beginning January 3, 1989; ordered by state.
All of the elections involved the Class 1 seats.
| State | Incumbent | Incumbent | Incumbent | Result | Candidates |
| State | Senator | Party | Electoral history | Result | Candidates |
| Arizona | Dennis DeConcini | Democratic | 1976 1982 | Incumbent re-elected. | ▌Y Dennis DeConcini (Democratic) 56.7% ▌Keith DeGreen (Republican) 41.1% ▌Rich Tompkins (Libertarian) 1.8% |
| California | Pete Wilson | Republican | 1982 | Incumbent re-elected. | ▌Y Pete Wilson (Republican) 52.7% ▌Leo T. McCarthy (Democratic) 44.0% Others ▌Maria E. Muñoz (Peace and Freedom) 1.7% ▌Jack Dean (Libertarian) 0.8% ▌Merton D. Short (American Independent) 0.7% |
| Connecticut | Lowell Weicker | Republican | 1970 1976 1982 | Incumbent lost re-election. Democratic gain. | ▌Y Joe Lieberman (Democratic) 49.7% ▌Lowell Weicker (Republican) 49.0% Others ▌Howard Grayson (Libertarian) 0.9% ▌Melissa Fisher (New Alliance) 0.3% |
| Delaware | William Roth | Republican | 1970 1971 (appointed) 1976 1982 | Incumbent re-elected. | ▌Y William Roth (Republican) 62.1% ▌S. B. Woo (Democratic) 37.9% |
| Florida | Lawton Chiles | Democratic | 1970 1976 1982 | Incumbent retired. Republican gain. | ▌Y Connie Mack III (Republican) 50.4% ▌Buddy MacKay (Democratic) 49.6% |
| Hawaii | Spark Matsunaga | Democratic | 1976 1982 | Incumbent re-elected. | ▌Y Spark Matsunaga (Democratic) 76.5% ▌Maria M. Hustace (Republican) 20.7% ▌Ken Schoolland (Libertarian) 2.8% |
| Indiana | Richard Lugar | Republican | 1976 1982 | Incumbent re-elected. | ▌Y Richard Lugar (Republican) 67.7% ▌Jack Wickes (Democratic) 32.3% |
| Maine | George J. Mitchell | Democratic | 1980 (appointed) 1982 | Incumbent re-elected. | ▌Y George J. Mitchell (Democratic) 81.1% ▌Jasper S. Wyman (Republican) 18.9% |
| Maryland | Paul Sarbanes | Democratic | 1976 1982 | Incumbent re-elected. | ▌Y Paul Sarbanes (Democratic) 61.8% ▌Alan Keyes (Republican) 38.2% |
| Massachusetts | Ted Kennedy | Democratic | 1962 (special) 1964 1970 1976 1982 | Incumbent re-elected. | ▌Y Ted Kennedy (Democratic) 65.0% ▌Joe Malone (Republican) 33.9% Others ▌Mary Fridley (New Alliance) 0.6% ▌Freda Lee Nason (Libertarian) 0.5% |
| Michigan | Donald Riegle | Democratic | 1976 1976 (appointed) 1982 | Incumbent re-elected. | ▌Y Donald Riegle (Democratic) 60.4% ▌James Whitney Dunn (Republican) 38.5% Others ▌Dick Jacobs (Libertarian) 0.8% ▌Sally Bier (Workers Against Concessions) 0.3% |
| Minnesota | David Durenberger | Republican | 1978 (special) 1982 | Incumbent re-elected. | ▌Y David Durenberger (Republican) 56.2% ▌Skip Humphrey (DFL) 40.9% Others ▌Polly Mann (Progressive Issues) 2.1% ▌Derrick Grimmer (Grassroots) 0.4% ▌Arlen Overvig (Libertarian) 0.2% ▌Wendy Lyons (Socialist Workers) 0.1% |
| Mississippi | John C. Stennis | Democratic | 1947 (special) 1952 1958 1964 1970 1976 1982 | Incumbent retired. Republican gain. | ▌Y Trent Lott (Republican) 54.1% ▌Wayne Dowdy (Democratic) 45.9% |
| Missouri | John Danforth | Republican | 1976 1976 (appointed) 1982 | Incumbent re-elected. | ▌Y John Danforth (Republican) 67.7% ▌Jay Nixon (Democratic) 31.7% ▌John Guze (Libertarian) 0.6% |
| Montana | John Melcher | Democratic | 1976 1982 | Incumbent lost re-election. Republican gain. | ▌Y Conrad Burns (Republican) 51.9% ▌John Melcher (Democratic) 48.1% |
| Nebraska | David Karnes | Republican | 1987 (appointed) | Interim appointee lost election. Democratic gain. | ▌Y Bob Kerrey (Democratic) 56.7% ▌David Karnes (Republican) 41.7% ▌Ernie Chambers (New Alliance) 1.6% |
| Nevada | Chic Hecht | Republican | 1982 | Incumbent lost re-election. Democratic gain. | ▌Y Richard Bryan (Democratic) 51.3% ▌Chic Hecht (Republican) 47.1% ▌James Frye (Libertarian) 1.6% |
| New Jersey | Frank Lautenberg | Democratic | 1982 1982 (appointed) | Incumbent re-elected. | ▌Y Frank Lautenberg (Democratic) 53.5% ▌Pete Dawkins (Republican) 45.2% Others ▌Joseph Job (Independent) 0.7% ▌Jerry Zeldin (Libertarian) 0.4% ▌Thomas Fiske (Socialist Workers) 0.2% |
| New Mexico | Jeff Bingaman | Democratic | 1982 | Incumbent re-elected. | ▌Y Jeff Bingaman (Democratic) 63.2% ▌Bill Valentine (Republican) 36.8% |
| New York | Daniel Patrick Moynihan | Democratic | 1976 1982 | Incumbent re-elected. | ▌Y Daniel Patrick Moynihan (Democratic) 67.3% ▌Robert R. McMillan (Republican) 31.6% |
| North Dakota | Quentin Burdick | Democratic-NPL | 1960 (special) 1964 1970 1976 1982 | Incumbent re-elected. | ▌Y Quentin Burdick (Democratic-NPL) 59.5% ▌Earl Strinden (Republican) 39.1% ▌Kenneth C. Gardner (Libertarian) 1.5% |
| Ohio | Howard Metzenbaum | Democratic | 1974 (appointed) 1974 (lost) 1974 (resigned) 1976 1976 (appointed) 1982 | Incumbent re-elected. | ▌Y Howard Metzenbaum (Democratic) 56.9% ▌George Voinovich (Republican) 43.1% |
| Pennsylvania | John Heinz | Republican | 1976 1982 | Incumbent re-elected. | ▌Y John Heinz (Republican) 66.4% ▌Joe Vignola (Democratic) 32.4% Others ▌Darcy Richardson (Consumer) 0.6% ▌Henry Haller (Libertarian) 0.3% ▌Samuel Cross (Populist) 0.1% ▌Sam Blancato (New Alliance) 0.1% |
| Rhode Island | John Chafee | Republican | 1976 1976 (appointed) 1982 | Incumbent re-elected. | ▌Y John Chafee (Republican) 54.3% ▌Richard A. Licht (Democratic) 45.7% |
| Tennessee | Jim Sasser | Democratic | 1976 1982 | Incumbent re-elected. | ▌Y Jim Sasser (Democratic) 65.1% ▌Bill Anderson (Republican) 34.5% ▌Khalil-Ullah Al-Muhaymin (Independent) 0.4% |
| Texas | Lloyd Bentsen | Democratic | 1970 1976 1982 | Incumbent re-elected. | ▌Y Lloyd Bentsen (Democratic) 59.2% ▌Beau Boulter (Republican) 40.0% ▌Jeff Daiell (Libertarian) 0.8% |
| Utah | Orrin Hatch | Republican | 1976 1982 | Incumbent re-elected. | ▌Y Orrin Hatch (Republican) 67.1% ▌Brian Moss (Democratic) 31.7% Others ▌Robert J. Smith (American) 0.9% ▌William M. Arth (Socialist Workers) 0.2% |
| Vermont | Robert Stafford | Republican | 1971 (appointed) 1972 (special) 1976 1982 | Incumbent retired. Republican hold. | ▌Y Jim Jeffords (Republican) 67.9% ▌William Gray (Democratic) 29.8% Others ▌Jerry Levy (Liberty Union) 1.1% ▌King Milne (Independent) 1.0% |
| Virginia | Paul Trible | Republican | 1982 | Incumbent retired. Democratic gain. | ▌Y Chuck Robb (Democratic) 71.2% ▌Maurice A. Dawkins (Republican) 28.8% |
| Washington | Daniel J. Evans | Republican | 1983 (appointed) 1983 (special) | Incumbent retired. Republican hold. | ▌Y Slade Gorton (Republican) 50.7% ▌Mike Lowry (Democratic) 49.3% |
| West Virginia | Robert Byrd | Democratic | 1958 1964 1970 1976 1982 | Incumbent re-elected. | ▌Y Robert Byrd (Democratic) 63.2% ▌M. Jay Wolfe (Republican) 36.8% |
| Wisconsin | William Proxmire | Democratic | 1957 (special) 1958 1964 1970 1976 1982 | Incumbent retired. Democratic hold. | ▌Y Herb Kohl (Democratic) 52.2% ▌Susan Engeleiter (Republican) 47.8% |
| Wyoming | Malcolm Wallop | Republican | 1976 1982 | Incumbent re-elected. | ▌Y Malcolm Wallop (Republican) 50.4% ▌John Vinich (Democratic) 49.6% |

## Closest races

In eleven races the margin of victory was under 10%.
| State | Party of winner | Margin |
| Wyoming | Republican | 0.73% |
| Connecticut | Democratic (flip) | 0.77% |
| Florida | Republican (flip) | 0.85% |
| Washington | Republican | 2.17% |
| Montana | Republican (flip) | 3.73% |
| Nevada | Democratic (flip) | 4.06% |
| Wisconsin | Democratic | 4.53% |
| Mississippi | Republican (flip) | 7.82% |
| New Jersey | Democratic | 8.37% |
| California | Republican | 8.77% |
| Rhode Island | Republican | 9.19% |
Ohio was the tipping point state with a margin of 13.95%.

## Arizona

Incumbent Democrat Dennis DeConcini was reelected to a third term over Republican Keith DeGreen, Marine veteran and financial advisor.
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Dennis DeConcini (Incumbent) | 660,403 | 56.71% | −0.20% |
| | Republican | Keith DeGreen | 478,060 | 41.05% | +0.75% |
| | Libertarian | Rick Tompkins | 20,849 | 1.79% | −0.99% |
| | New Alliance | Ed Finkelstein | 5,195 | 0.45% | |
| | Write-ins | | 32 | 0.00% | |
| Majority | Majority | Majority | 182,343 | 15.66% | −0.95% |
| Turnout | Turnout | Turnout | 1,164,539 | | |
| | Democratic hold | Democratic hold | Swing | | |

## California

Incumbent Republican Pete Wilson won re-election to a second term over Democrat Leo T. McCarthy, Lieutenant Governor of California and former Speaker of the California State Assembly. As of 2020, this is the last Senate election in California won by a Republican.
General election results :
| Party | Party | Candidate | Votes | % |
| | Republican | Pete Wilson (Incumbent) | 5,143,409 | 52.8% |
| | Democratic | Leo T. McCarthy | 4,287,253 | 44.0% |
| | Peace and Freedom | Maria Elizabeth Munoz | 166,600 | 1.7% |
| | Libertarian | Jack Dean | 79,997 | 0.8% |
| | American Independent | Merton D. Short | 66,291 | 0.7% |
| Total votes | Total votes | Total votes | 9,743,550 | 100.00% |
| Majority | Majority | Majority | 856,156 | 8.8% |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Connecticut

Incumbent Republican Lowell P. Weicker Jr. ran for re-election to a fourth term, but was defeated by Democratic candidate Joe Lieberman, the Connecticut Attorney General and eventual 2000 nominee for Vice President of the United States, who would remain in office until his retirement in 2013.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Joseph Lieberman | 688,499 | 49.8% |
| | Republican | Lowell Weicker (Incumbent) | 677,903 | 49.0% |
| | Libertarian | Howard A. Grayson Jr. | 12,409 | 0.9% |
| | New Alliance | Melissa M. Fisher | 4,154 | 0.3% |
| Total votes | Total votes | Total votes | 1,379,362 | 100.0% |
| Majority | Majority | Majority | 10,596 | 0.8% |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## Delaware

Incumbent Republican William Roth won re-election to a fourth term, beating Democrat Shien Biau Woo, Lieutenant Governor of Delaware
Democratic Party primary results :
| Party | Party | Candidate | Votes | % |
| | Democratic | S. B. Woo | 20,225 | 50.09 |
| | Democratic | Samuel Beard | 20,154 | 49.91 |
| Total votes | Total votes | Total votes | 40,379 | 100.00 |
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | William V. Roth (Incumbent) | 151,115 | 62.06% | +6.89% |
| | Democratic | S.B. Woo | 92,378 | 37.94% | −6.27% |
| Majority | Majority | Majority | 58,737 | 24.12% | +13.15% |
| Turnout | Turnout | Turnout | 243,493 | | |
| | Republican hold | Republican hold | Swing | | |

## Florida

Incumbent Democrat Lawton Chiles decided to retire instead of seeking a fourth term. Republican U.S. Representative Connie Mack III won the open seat over Democratic Congressman Buddy Mackay.
This senate election was heavily targeted by both parties. U.S. Representative Mack announced his candidacy back in October 1987. President Ronald Reagan endorsed Mack in June 1988 to allow Mack to focus on the general election, and easily won the September 6 Republican primary against U.S. Attorney Robert Merkle. In May 1988, then-Congressman MacKay announced he would run for the open seat, and defeated Insurance Commissioner Bill Gunter in a close October 4 runoff election.
The general election soon became nasty, with Mackay portraying Mack as "extremist." Mack also attacked his opponent in television ads by connecting him to liberal Massachusetts Governor and Democratic presidential nominee Michael Dukakis. Mack had help from vice presidential candidate Dan Quayle. The election was so close there was a recount until Mackay conceded eight days after election day.
Democratic primary results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bill Gunter | 383,721 | 38.00 |
| | Democratic | Buddy MacKay | 263,946 | 26.14 |
| | Democratic | Dan Mica | 179,524 | 17.78 |
| | Democratic | Pat Collier Frank | 119,277 | 11.81 |
| | Democratic | Claude R. Kirk Jr. | 51,387 | 5.09 |
| | Democratic | Fred Rader | 11,820 | 1.17 |
| Total votes | Total votes | Total votes | 1,009,675 | 100 |
Democratic primary runoff results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Buddy MacKay | 369,266 | 52.00 |
| | Democratic | Bill Gunter | 340,918 | 48.00 |
| Total votes | Total votes | Total votes | 710,184 | 100 |
Republican primary results :
| Party | Party | Candidate | Votes | % |
| | Republican | Connie Mack III | 405,296 | 61.78 |
| | Republican | Robert Merkle | 250,730 | 38.22 |
| Total votes | Total votes | Total votes | 656,026 | 100 |
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Connie Mack III | 2,051,071 | 50.42% | +12.15% |
| | Democratic | Buddy MacKay | 2,016,553 | 49.57% | −12.15% |
| | Write-ins | | 585 | 0.01% | |
| Majority | Majority | Majority | 34,518 | 0.85% | −22.61% |
| Total votes | Total votes | Total votes | 4,068,209 | 100.00% | |
| | Republican gain from Democratic | Republican gain from Democratic | Swing | | |

## Hawaii

Incumbent Democrat Spark Matsunaga won re-election to a third term, beating Republican cattle rancher Maria Hustace.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Spark Matsunaga (Incumbent) | 247,941 | 76.6% |
| | Republican | Maria Hustace | 66,987 | 20.7% |
| | Libertarian | Ken Schoolland | 8,948 | 2.8% |
| Total votes | Total votes | Total votes | 323,876 | 100.00% |
| Majority | Majority | Majority | 180,954 | 55.9% |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Indiana

Incumbent Republican Richard Lugar was re-elected to a third term over Democratic attorney Jack Wickes.
Lugar, a popular incumbent, had token opposition in this election. An April 1988 poll showed that Lugar lead 65% to 23%. By June, Lugar raised over $2 million, while Wickes raised just over $100,000. Lugar agreed to debate Wickes on September 10, 1988.
Lugar won overall with two-thirds of the vote and won 91 of Indiana's 92 counties, Wickes won only the Democratic stronghold of Lake County.
General election results :
| Party | Party | Candidate | Votes | % |
| | Republican | Richard Lugar (Incumbent) | 1,430,525 | 68.1% |
| | Democratic | Jack Wickes | 668,778 | 31.9% |
| Total votes | Total votes | Total votes | 2,099,303 | 100.00% |
| Majority | Majority | Majority | 761,747 | 36.2% |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Maine

Incumbent Democrat George J. Mitchell won re-election to a second full term over Republican Jasper Wyman, leader of Maine Christian Civic League and businessman. As of 2020, this is the last Senate election in Maine won by a Democrat.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | George Mitchell (Incumbent) | 452,581 | 81.3% |
| | Republican | Jasper Wyman | 104,164 | 18.7% |
| Total votes | Total votes | Total votes | 556,745 | 100.00% |
| Majority | Majority | Majority | 348,417 | 62.6% |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Maryland

Incumbent Democratic Paul Sarbanes was reelected to a third term over Republican Alan Keyes, former Assistant Secretary of State for International Organization Affairs.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Paul Sarbanes (Incumbent) | 999,166 | 61.8 |
| | Republican | Alan Keyes | 617,537 | 38.2 |
| | Independent | Imad A. Ahmad (Write In) | 349 | 0.0 |
| | Independent | Rashaad Ali (Write In) | 13 | 0.0 |
| Majority | Majority | Majority | 381,629 | 23.6 |
| Turnout | Turnout | Turnout | 1,617,065 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Massachusetts

Incumbent Democrat Ted Kennedy won re-election to his sixth (his fifth full) term over Republican Joseph D. Malone.
General Election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Ted Kennedy (Incumbent) | 1,693,344 | 64.97 | +4.16 |
| | Republican | Joseph D. Malone | 884,267 | 33.93 | −4.33 |
| | New Alliance | Mary Fridley | 15,208 | 0.58 | +0.58 |
| | Libertarian | Freda Lee Nason | 13,199 | 0.51 | −0.41 |
| | | All others | 207 | 0.01 | +0 |
| Total votes | Total votes | Total votes | 2,606,225 | 87.77% | |
| | Democratic hold | Democratic hold | Swing | | |

## Michigan

Incumbent Democrat Don Riegle won re-election to a third term over Republican U.S. Congressman James Whitney Dunn.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Donald Riegle (incumbent) | 2,116,865 | 60.4 |
| | Republican | Jim Dunn | 1,348,216 | 38.5 |
| | Libertarian | Dick Jacobs | 27,116 | 0.8 |
| | Workers Against Concessions | Sally Bier | 8,908 | 0.3 |
| | Independent | Mark Friedman | 4,821 | 0.1 |
| Total votes | Total votes | Total votes | 3,505,926 | 100.00% |
| Majority | Majority | Majority | 768,649 | 21.9% |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Minnesota

Incumbent Republican David Durenberger won re-election to his second full term, beating Democrat Skip Humphrey, the Minnesota Attorney General and former state senator.
General election results :
| Party | Party | Candidate | Votes | % |
| | Republican | David Durenberger (incumbent) | 1,176,210 | 56.2 |
| | Democratic | Skip Humphrey | 856,694 | 40.9 |
| | Minnesota Progressive Party | Polly Mann | 44,474 | 2.1 |
| | Grassroots | Derrick Grimmer | 9,016 | 0.4 |
| | Libertarian | Arlen Overvig | 4,039 | 0.2 |
| | Socialist Workers | Wendy Lyons | 3,105 | 0.2 |
| Total votes | Total votes | Total votes | 2,093,538 | 100.00% |
| Majority | Majority | Majority | 319,516 | 15.3 |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Mississippi

Incumbent Democrat John C. Stennis decided to retire instead of seeking an eighth term (and his seventh full term). Republican Trent Lott won the open seat, beating Democrat Wayne Dowdy, U.S. Congressman from the 4th district.
General election results :
| Party | Party | Candidate | Votes | % |
| | Republican | Trent Lott | 510,380 | 53.9 |
| | Democratic | Wayne Dowdy | 436,339 | 46.1 |
| Total votes | Total votes | Total votes | 946,719 | 100.00% |
| Majority | Majority | Majority | 74,041 | 7.8 |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Missouri

Incumbent Republican John Danforth won re-election over Democratic state senator and future Governor Jay Nixon.
1988 Missouri United States Senate election :
| Party | Party | Candidate | Votes | % |
| | Republican | John Danforth (Incumbent) | 1,407,416 | 67.70 |
| | Democratic | Jay Nixon | 660,045 | 31.75 |
| | Libertarian | John Guze | 11,410 | 0.55 |
| | | Write-In Candidates | 4 | 0.00 |
| Majority | Majority | Majority | 747,371 | 35.95 |
| Turnout | Turnout | Turnout | 2,078,875 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Montana

Incumbent John Melcher, who was first elected to the Senate in 1976 and was re-elected in 1982, ran for re-election. After winning the Democratic primary, he faced Yellowstone County Commissioner Conrad Burns in the general election, and in the general election a grueling campaign followed. Ultimately, Melcher was narrowly defeated in his bid for re-election by Burns.
Democratic Party primary results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Jack Melcher (Incumbent) | 88,457 | 74.54 |
| | Democratic | Bob Kelleher | 30,212 | 25.46 |
| Total votes | Total votes | Total votes | 118,669 | 100.00 |
Republican Primary results :
| Party | Party | Candidate | Votes | % |
| | Republican | Conrad Burns | 63,330 | 84.71 |
| | Republican | Tom Faranda | 11,427 | 15.29 |
| Total votes | Total votes | Total votes | 74,757 | 100.00 |
1988 United States Senate election in Montana :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | Conrad Burns | 189,445 | 51.87% | +10.20% |
| | Democratic | John Melcher (Incumbent) | 175,809 | 48.13% | −6.33% |
| Majority | Majority | Majority | 13,636 | 3.73% | −9.06% |
| Turnout | Turnout | Turnout | 365,254 | | |
| | Republican gain from Democratic | Republican gain from Democratic | Swing | | |

## Nebraska

Republican David Karnes decided to seek election to his first complete term after being appointed to the seat of the late Edward Zorinsky in March 1987, but was soundly defeated by Democratic former governor Bob Kerrey in the November general election.
Republican primary results :
| Party | Party | Candidate | Votes | % |
| | Republican | David Karnes | 117,439 | 55 |
| | Republican | Hal Daub | 96,436 | 45 |
1988 Nebraska United States Senate election :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bob Kerrey | 378,717 | 56.71 |
| | Republican | David Karnes (Incumbent) | 278,250 | 41.66 |
| | New Alliance | Ernie Chambers | 10,372 | 1.55 |
| | | Write-In Candidates | 521 | 0.08 |
| Majority | Majority | Majority | 100,467 | 15.04 |
| Turnout | Turnout | Turnout | 667,860 | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## Nevada

Incumbent Republican Chic Hecht ran for re-election to a second term, but lost to Democratic governor Richard Bryan.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Richard Bryan | 175,548 | 50.21% |
| | Republican | Chic Hecht (Incumbent) | 161,336 | 46.14% |
| | None | None of These Candidates | 7,242 | 2.07% |
| | Libertarian | James Frye | 5,523 | 1.58% |
| Majority | Majority | Majority | 14,212 | 4.06% |
| Turnout | Turnout | Turnout | 349,649 | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## New Jersey

Incumbent Democrat Frank Lautenberg won re-election to a second term with a margin of 8.37% over Republican Pete Dawkins, military veteran and CEO of Primerica Financial Services, Inc.
The campaign was full of political mudslinging, with Lautenberg accusing Dawkins of being a carpetbagger, noting his very brief residency in the state, and also accusing Dawkins' campaign of lying about his war record. Dawkins accused Lautenberg of running a smear campaign against, called him a "swamp dog", and criticized him for saying he voted eight times against a senatorial pay raise without mentioning the fact that he did vote once for the pay raise.
1988 United States Senate election in New Jersey :
| Party | Party | Candidate | Votes | % |
| | Democratic | Frank Lautenberg (Incumbent) | 1,599,905 | 53.55% |
| | Republican | Pete Dawkins | 1,349,937 | 45.18% |
| | Independent | Joseph F. Job | 20,091 | 0.67% |
| | Libertarian | Jerry Zeldin | 12,354 | 0.41% |
| | Socialist | Thomas A. Fiske | 5,347 | 0.18% |
| Majority | Majority | Majority | 249,968 | 8.37% |
| Turnout | Turnout | Turnout | 2,987,634 | 100.00% |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## New Mexico

Incumbent Democrat Jeff Bingaman won re-election to a second term, beating Republican New Mexico State Senator Bill Valentine.
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jeff Bingaman (Incumbent) | 321,983 | 63.31% | +9.53% |
| | Republican | Bill Valentine | 186,579 | 36.68% | −9.54% |
| | Write-ins | | 36 | 0.01% | |
| Majority | Majority | Majority | 135,404 | 26.62% | +19.08% |
| Turnout | Turnout | Turnout | 508,598 | | |
| | Democratic hold | Democratic hold | Swing | | |

## New York

Incumbent Democrat Daniel Patrick Moynihan won re-election to a third term, over Republican Robert R. McMillan, business executive of Avon Products and Reagan Administration advisor.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Daniel Patrick Moynihan (Incumbent) | 4,048,649 | 67.0 |
| | Republican | Robert R. McMillan | 1,875,784 | 31.1 |
| | Right to Life | Adelle R. Nathanson | 64,845 | 1.1 |
| | Independent Progressive | Charlene Mitchell | 14,770 | 0.2 |
| | Workers World | Lydia Bayoneta | 13,573 | 0.2 |
| | Libertarian | William P. McMillen | 12,064 | 0.2 |
| | Socialist Workers | James E. Harris | 11,239 | 0.2 |
| Total votes | Total votes | Total votes | 6,040,924 | 100.00% |
| Majority | Majority | Majority | 2,172,865 | 35.9% |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## North Dakota

The incumbent, Quentin Burdick of the North Dakota Democratic NPL Party, sought and received re-election to his sixth term, defeating Republican candidate Earl Strinden.
Only Burdick filed as a Dem-NPLer, and the endorsed Republican candidate was Earl Strinden of Grand Forks, North Dakota, who was President of the University of North Dakota Alumni Association. As in the Burdick's previous re-election campaign, the senator's age became an issue for voters as he was 80 years old during the campaign. However, challenger Strinden commented that he did not want to raise the age issue. Burdick and Strinden won the primary elections for their respective parties.
The Burdick campaign hired high-profile Washington, D.C. campaign consultant Bob Squire of Squire Eskew Communications. To counter the potential age issue, Burdick successfully focused the message on the "clout" he had earned over decades in the Senate, as well as his Chairmanship of Senate Agricultural Appropriations sub-committee and his Chairmanship of the Senate Environment and Public Works Committee.
One independent candidate, Kenneth C. Gardner, also filed before the deadline, officially calling himself a libertarian. Gardner had previously run for North Dakota's other United States Senate seat an independent in 1974, challenging Milton Young. He only received 853 votes in that election.
1988 United States Senate election, North Dakota :
| Party | Party | Candidate | Votes | % |
| | Democratic–NPL | Quentin Burdick (incumbent) | 171,899 | 59.45 |
| | Republican | Earl Strinden | 112,937 | 39.06 |
| | Independent | Kenneth C. Gardner | 4,334 | 1.50 |
| Majority | Majority | Majority | 58,962 | 20.39 |
| Turnout | Turnout | Turnout | 289,170 | |
| | Democratic–NPL hold | Democratic–NPL hold | Democratic–NPL hold | Democratic–NPL hold |

## Ohio

Incumbent Democrat Howard Metzenbaum won re-election over George Voinovich, Mayor of Cleveland and former Lieutenant Governor of Ohio.
1988 Ohio United States Senate election :
| Party | Party | Candidate | Votes | % |
| | Democratic | Howard Morton Metzenbaum (Incumbent) | 2,480,038 | 56.97% |
| | Republican | George Victor Voinovich | 1,872,716 | 42.31% |
| | Independent | David Marshall | 151 | 0.00% |
| Majority | Majority | Majority | 607,322 | 8.68% |
| Turnout | Turnout | Turnout | 4,352,905 | 100.00% |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Pennsylvania

Incumbent Republican H. John Heinz III successfully sought re-election to another term, defeating Democratic nominee Joe Vignola, Philadelphia City Controller.
Joe Vignola was not expected by Democratic Party leaders to have a substantial chance at defeating the popular incumbent John Heinz, even predicting that Vignola would become "Heinz's 58th variety," referring to an advertising slogan of the H. J. Heinz Company. Heinz, knowing this, ran a low-profile re-election campaign and was safely ahead in polling. Vignola traveled across Pennsylvania promoting an increase in domestic spending, including education and healthcare, while decreasing the defense budget to compensate. Vignola ran a positive campaign, in contrast with Cyril Wecht six years previously, although many Democratic ward leaders and committee members had given up on the campaign and had stopped campaigning for Vignola.
Heinz easily defeated Vignola to win the election and another term in the Senate, carrying every Pennsylvania county except Philadelphia, Vignola's home town, and by a comfortable 1.49 million vote margin. Heinz performed well in suburban areas, as well as the central, southwestern and northeastern portions of the state. Outside of Philadelphia, Vignola's best county-wide showing was in Mercer County, where he won 36% of the vote, and his poorest county-wide performance was in Snyder County, where he won 12% of the vote. Although Heinz's landslide victory was largely expected among Democratic leaders, Heinz won by a wide margin despite the Democrats' 551,000-voter registration advantage statewide.
Heinz died in an airplane crash on April 4, 1991, in Lower Merion Township, Pennsylvania. Democrat Harris Wofford was appointed on May 8 to fill the vacancy caused by Heinz's death, and subsequently won a special election in November 1991. In the 1994 election, however, Wofford was defeated by Republican Rick Santorum.
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | H. John Heinz III (Incumbent) | 2,901,715 | 66.45% | +7.17% |
| | Democratic | Joseph Vignola | 1,416,764 | 32.45% | −6.75% |
| | Consumer | Darcy Richardson | 25,273 | 0.58% | +0.12% |
| | Libertarian | Henry E. Haller II | 11,822 | 0.27% | −0.26% |
| | Populist | Samuel Cross | 6,455 | 0.15% | +0.15% |
| | New Alliance | Sam Blancato | 4,569 | 0.11% | +0.11% |
| Majority | Majority | Majority | 1,484,951 | 34.00% | +13.92% |
| Total votes | Total votes | Total votes | 4,366,598 | 100.00% | |
| | Republican hold | Republican hold | Swing | | |

## Rhode Island

Incumbent Republican John Chafee won re-election to a third term, beating Democratic lieutenant governor and former state senator Richard Licht.
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Republican | John Chafee (Incumbent) | 217,273 | 54.59% | +3.39% |
| | Democratic | Richard Licht | 180,717 | 45.41% | −3.39% |
| Majority | Majority | Majority | 36,556 | 9.19% | +6.79% |
| Turnout | Turnout | Turnout | 397,990 | | |
| | Republican hold | Republican hold | Swing | | |

## Tennessee

Incumbent Democrat Jim Sasser won re-election to a third term over Republican Bill Anderson.
Tennessee United States Senate election 1988 :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Jim Sasser (Incumbent) | 1,020,061 | 65.09% | |
| | Republican | Bill Anderson | 541,033 | 34.52% | −30.57% |
| | Independent | Khalil-Ullah Al-Muhaymin | 6,042 | 0.39% | −64.70% |
| | Others | (W) Others | 45 | 0.00 | −65.09% |
| Majority | Majority | Majority | 479,028 | 30.57% | |
| Turnout | Turnout | Turnout | 1,561,094 | | |
| | Democratic hold | Democratic hold | Swing | | |

## Texas

Incumbent Democrat Lloyd Bentsen won re-election to a fourth term defeating Republican Representative Beau Boulter.
Bentsen easily won the Democratic nomination for another term, while Boulter came through a run-off in the Republican primary defeating Wes Gilbreath. After being nominated for the senate Bentsen was chosen by Michael Dukakis as his vice-presidential running mate and therefore ran for both the Senate and the vice-presidency at the same time. Bentsen was always the favorite for the senate election and won with 59.2% of the vote, compared to 40% for Boulter.
As of 2024, this was the last time a Democrat won a United States Senate election in Texas.
In the Democratic primary Democratic senator Lloyd Bentsen defeated the same opponent he had beaten in 1982, Joe Sullivan, a psychology professor from San Antonio.
Bentsen had been senator from Texas since first winning election in 1970 and had been re-elected in 1976 and 1982. He was also Chairman of the Senate Finance Committee and the clear favourite for re-election in 1988. Sullivan stood on a platform calling for reduced spending by the federal government, but had been easily defeated by Bentsen in the 1982 Democratic primary. This was repeated in 1988 with Bentsen winning the primary with over 80% of the vote.
March 8 Democratic primary results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Lloyd Bentsen | 1,365,736 | 84.8 |
| | Democratic | Joe Sullivan | 244,805 | 15.2 |
| Total votes | Total votes | Total votes | 1,610,541 | 100 |
Four candidates competed for the Republican nomination; U.S. representative Beau Boulter, former state representative Milton Fox, millionaire Houston businessman Wes Gilbreath and businessman Ned Snead. Boulter was a two-term representative for the 13th district, while Gilbreath was competing in his first election, but spent $500,000 on the primary.
Wes Gilbreath led in the March primary with 36.7%, but as no candidate won a majority, went into a run-off election against Beau Boulter who came second with 30.5%.
March 8 Republican primary results :
| Party | Party | Candidate | Votes | % |
| | Republican | Wes Gilbreath | 275,080 | 36.7 |
| | Republican | Beau Boulter | 228,676 | 30.5 |
| | Republican | Milton Fox | 138,031 | 18.4 |
| | Republican | Ned Snead | 107,560 | 14.4 |
| Total votes | Total votes | Total votes | 749,347 | 100 |
There were few policy differences between Boulter and Gilbreath, with both candidates being conservatives who opposed abortion and called for reduced government spending. Gilbreath spent about one million dollars of his money in his contest for the primary, while Boulter spent about $250,000. However Boulter won endorsements from many Texas Republican leaders, including the candidates who had come third and fourth in the March primary, as well as from anti-abortion groups.
Boulter won the April run-off for the Republican nomination with just over 60% of the vote.
April 12 Republican run-off results :
| Party | Party | Candidate | Votes | % |
| | Republican | Beau Boulter | 111,134 | 60.2 |
| | Republican | Wes Gilbreath | 73,573 | 39.8 |
| Total votes | Total votes | Total votes | 184,707 | 100 |
In July 1988 the Democratic presidential nominee Michael Dukakis chose Lloyd Bentsen to be the Democratic vice-presidential candidate. As the Texas Democrats had already had their primary for senate candidate, Bentsen could not be replaced on the ballot. Bentsen was however able to run both for the Senate and for vice-president as Lyndon Johnson had gotten Texas law changed in 1960 to allow Johnson to do the same at the 1960 election.
Lloyd Bentsen won the senate election by a clear margin over Beau Boulter, at the same time as he and Michael Dukakis lost the presidential race, with George Bush winning Texas with 56% of the vote compared to 43% for Dukakis. Bentsen's vote total in the senate election was reported to be at the time the highest vote total in any Texas statewide election. Bentsen then returned to the Senate and remained until the next four years when he was appointed the Secretary of the Treasury under President Bill Clinton. Had the Dukakis–Bentsen ticket won, Bentsen would have become U.S. Vice President and forced to resign his Senate seat, which would have led to a 1990 special election. It would also have led Republican Governor Bill Clements to temporarily appoint an interim replacement.
General election results :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Lloyd Bentsen (Incumbent) | 3,149,806 | 59.2 | +0.6 |
| | Republican | Beau Boulter | 2,129,228 | 40.0 | −0.5 |
| | Libertarian | Jeff Daiell | 44,572 | 0.8 | |
| Majority | Majority | Majority | 1,020,578 | 19.2 | +1.1 |
| Turnout | Turnout | Turnout | 5,323,606 | | |
| | Democratic hold | Democratic hold | Swing | | |

## Utah

Incumbent Orrin Hatch easily won re-election to a third term over Democrat Brian Moss.
1988 United States Senate election in Utah :
| Party | Party | Candidate | Votes | % |
| | Republican | Orrin Hatch (Incumbent) | 430,084 | 67.13% |
| | Democratic | Brian H. Moss | 203,364 | 31.74% |
| | American | Robert J. Smith | 6,016 | 0.94% |
| | Socialist Workers | William M. Arth | 1,233 | 0.19% |
| Majority | Majority | Majority | 227,720 | 35.39% |
| Total votes | Total votes | Total votes | 640,697 | 100.00% |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Vermont

Incumbent Republican Robert Stafford did not run for re-election to another term in the United States Senate. Republican candidate Jim Jeffords defeated Democratic candidate Bill Gray to succeed him.
Republican primary results :
| Party | Party | Candidate | Votes | % |
| | Republican | Jim Jeffords | 30,555 | 60.8 |
| | Republican | Mike Griffes | 19,593 | 38.9 |
| | Republican | Other | 128 | 0.3 |
| Total votes | Total votes | Total votes | '50,276' | '100' |
Democratic primary results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bill Gray | 23,138 | 91.5 |
| | Democratic | Other | 2,149 | 8.5 |
| Total votes | Total votes | Total votes | '25,287' | '100' |
1988 United States Senate election in Vermont :
| Party | Party | Candidate | Votes | % |
| | Republican | Jim Jeffords | 163,203 | 63.2 |
| | Democratic | Bill Gray | 71,469 | 29.8 |
| | Liberty Union | Jerry Levy | 2,506 | 1.0 |
| | Independent | King Milne | 2,424 | 1.0 |
| | N/A | Other | 509 | 0.2 |
| Majority | Majority | Majority | 91,736 | 33.4 |
| Total votes | Total votes | Total votes | 240,111 | 100.0 |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Virginia

Former Democratic governor Chuck Robb replaced Republican Senator Paul S. Trible Jr., who opted not to run for re-election. Robb beat Republican Maurice A. Dawkins, minister and black activist.
1988 United States Senate election in Virginia :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Chuck Robb | 1,474,086 | 71.25% | +22.45% |
| | Republican | Maurice A. Dawkins | 593,652 | 28.69% | −22.51% |
| | Write-ins | | 1,159 | 0.06% | |
| Majority | Majority | Majority | 880,434 | 42.56% | +40.18% |
| Turnout | Turnout | Turnout | 2,068,897 | | |
| | Democratic gain from Republican | Democratic gain from Republican | Swing | | |

## Washington

Incumbent Republican Daniel J. Evans decided to retire instead of running for re-election to a full term, after being appointed to the seat in 1983, and won election to a partial term that same year. Republican former U.S. Senator Slade Gorton, who had just lost a re-election bid in 1986, won the open seat over congressman Mike Lowry.
General election results :
| Party | Party | Candidate | Votes | % |
| | Republican | Slade Gorton | 944,359 | 51.09 |
| | Democratic | Mike Lowry | 904,183 | 48.91 |
| Majority | Majority | Majority | 40,176 | 2.17 |
| Turnout | Turnout | Turnout | 1,848,542 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## West Virginia

Incumbent Democrat Robert Byrd won re-election to a sixth term over Republican, State Senator Jay Wolfe.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Robert Byrd (Incumbent) | 410,983 | 64.8% |
| | Republican | Jay Wolfe | 223,564 | 35.2% |
| Total votes | Total votes | Total votes | 634,547 | 100.00% |
| Majority | Majority | Majority | 187,319 | 29.6% |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Wisconsin

Incumbent Democrat William Proxmire decided to retire, instead of running for re-election to a sixth full term. Democratic businessman Herb Kohl won the open seat, beating Republican state senator Susan Engeleiter.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Herb Kohl | 1,128,625 | 52.1% |
| | Republican | Susan Engeleiter | 1,030,440 | 47.6% |
| | Independent | George W. Zaehringer | 3,965 | 0.2% |
| | Socialist Workers | Patricia Grogan | 3,029 | 0.1% |
| | Independent | Arlyn F. Wollenburg | 1,198 | 0.1% |
| Total votes | Total votes | Total votes | 2,167,257 | 100.00% |
| Majority | Majority | Majority | 98,185 | 4.5% |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Wyoming

Incumbent Republican Malcolm Wallop ran for re-election to a fourth term, and was narrowly re-elected, defeating the Democratic state senator John Vinich by a margin of a little over 1,300 votes.
Despite being a reliably Republican state, Vinich, a Democrat, was able to impressively compete with Wallop. During the campaign, Wallop attacked Vinich as being a tax-and-spend liberal who was beholden to labor and anti-business. Vinich, in turn, cited his "A" score he got from the National Rifle Association of America due to his votes in the Wyoming Legislature to counter Wallop's attacks, and possibly attract conservative voters.
General election results :
| Party | Party | Candidate | Votes | % |
| | Republican | Malcolm Wallop (Incumbent) | 91,143 | 50.37% |
| | Democratic | John Vinich | 89,821 | 49.64% |
| Total votes | Total votes | Total votes | 180,964 | 100.00% |
| Majority | Majority | Majority | 1,322 | 0.73% |
| | Republican hold | Republican hold | Republican hold | Republican hold |