# 1956 United States Senate elections

The 1956 United States Senate elections were elections for the United States Senate that coincided with the re-election of President Dwight D. Eisenhower. The 32 seats of Class 3 were contested in regular elections, and three special elections were held to fill vacancies. Although Democrats gained two seats in regular elections, the Republicans gained two seats in special elections, leaving the party balance of the chamber unchanged.
Democrats defeated incumbents Herman Welker (R-Idaho), George H. Bender (R-Ohio), and James H. Duff (R-Pennsylvania), as well as winning a Republican-held seat in Colorado. Republicans defeated incumbent Earle C. Clements (D-Kentucky) as well as winning Democratic-held seats in Kentucky, New York, and West Virginia. Thus, this election caused Kentucky's Senate delegation to flip from two Democrats to two Republicans.
During the next Congress, Republican John D. Hoblitzell Jr. was appointed to the seat of deceased Senator Matthew M. Neely (D-WV), while Democrat William Proxmire won a special election for the seat of deceased Senator Joseph McCarthy (R-Wisconsin). Also, Democrat Ralph Yarborough won a special election for the seat of Price Daniel (D-Texas), who had resigned from the Senate after being elected Governor of Texas. The net result was to leave the party balance unchanged. Republicans would not win a Senate election in West Virginia again until 2014.

## Results summary

| 49 | 47 |
| Democratic | Republican |
Colored shading indicates party with largest share of that row.
| Parties | Parties | | | | Total |
| Parties | Parties | Democratic | Republican | Other | Total |
| Before these elections | Before these elections | 49 | 47 | 0 | 96 |
| Not up | Not up | 31 | 30 | — | 61 |
| | Class 1 (1952) | 11 | 20 | — | 31 |
| | Class 2 (1954) | 20 | 10 | — | 30 |
| Up | Up | 18 | 17 | — | 35 |
| | Class 3 (1950→1956) | 15 | 17 | — | 32 |
| | Special: Class 1 | 1 | 0 | — | 1 |
| | Special: Class 2 | 2 | 0 | — | 2 |
| Incumbent retired | Incumbent retired | 5 | 1 | — | 6 |
| | Held by same party | 2 | 0 | — | 2 |
| | Replaced by other party | 1 Republican replaced by 1 Democrat 3 Democrats replaced by 3 Republicans | 1 Republican replaced by 1 Democrat 3 Democrats replaced by 3 Republicans | — | 4 |
| | Result | 3 | 3 | 0 | 6 |
| Incumbent ran | Incumbent ran | 13 | 16 | — | 29 |
| | Won re-election | 12 | 13 | — | 25 |
| | 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 | 15 | 14 | 0 | 29 |
| Total elected | Total elected | 18 | 17 | 0 | 35 |
| Net change | Net change | | | | 0 |
| Nationwide vote | Nationwide vote | 23,291,351 | 22,219,450 | 406,207 | 45,917,008 |
| | Share | 50.72% | 48.39% | 0.88% | 100% |
| Result | Result | 49 | 47 | 0 | 96 |
Source: Clerk of the U.S. House of Representatives

## Gains, losses, and holds
### Retirements

One Republican and five Democrats retired instead of seeking re-election.
| State | Senator | Replaced by |
| Colorado | Eugene Millikin | John A. Carroll |
| Georgia | Walter F. George | Herman Talmadge |
| Kentucky (special) | Robert Humphreys | John Sherman Cooper |
| New York | Herbert H. Lehman | Jacob Javits |
| South Carolina (special) | Thomas A. Wofford | Strom Thurmond |
| West Virginia | William Laird III | Chapman Revercomb |

### Defeats

Three Republicans and one Democrat sought re-election but lost in the general election.
| State | Senator | Replaced by |
| Idaho | Herman Welker | Frank Church |
| Kentucky | Earle Clements | Thruston Ballard Morton |
| Ohio | George H. Bender | Frank Lausche |
| Pennsylvania | James H. Duff | Joseph S. Clark Jr. |

### Post-election changes

One Republican was appointed to the seat of a deceased Democrat. Two Democrats won special elections, one seat was previously held by a Democrat and another by a Republican. One Democrat was appointed to replace another Democrat.
| State | Senator | Replaced by |
| North Carolina | W. Kerr Scott | B. Everett Jordan |
| Texas | Price Daniel | Ralph Yarborough |
| West Virginia | Matthew M. Neely | John D. Hoblitzell Jr. |
| Wisconsin | Joseph McCarthy | William Proxmire |

## Change in composition
### Before the elections

| | | D$_1$ | D$_2$ | D$_3$ | D$_4$ | D$_5$ | D$_6$ | D$_7$ | D$_8$ |
| D$_{18}$ | D$_{17}$ | D$_{16}$ | D$_{15}$ | D$_{14}$ | D$_{13}$ | D$_{12}$ | D$_{11}$ | D$_{10}$ | D$_9$ |
| D$_{19}$ | D$_{20}$ | D$_{21}$ | D$_{22}$ | D$_{23}$ | D$_{24}$ | D$_{25}$ | D$_{26}$ | D$_{27}$ | D$_{28}$ |
| D$_{38}$ Ky. (sp) Ran | D$_{37}$ Ky. (reg) Ran | D$_{36}$ Ga. Retired | D$_{35}$ Florida Ran | D$_{34}$ Ark. Ran | D$_{33}$ Ariz. Ran | D$_{32}$ Ala. Ran | D$_{31}$ | D$_{30}$ | D$_{29}$ |
| D$_{39}$ La. Ran | D$_{40}$ Mo. Ran | D$_{41}$ Nev. Ran | D$_{42}$ N.Y. Retired | D$_{43}$ N.C. Ran | D$_{44}$ Okla. Ran | D$_{45}$ Ore. Ran | D$_{46}$ S.C. (reg) Ran | D$_{47}$ S.C. (sp) Retired | D$_{48}$ Washington Ran |
| Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | D$_{49}$ W.Virginia (sp) Retired |
| R$_{39}$ Maryland Ran | R$_{40}$ N.H. Ran | R$_{41}$ N.D. Ran | R$_{42}$ Ohio Ran | R$_{43}$ Pa. Ran | R$_{44}$ S.D. Ran | R$_{45}$ Utah Ran | R$_{46}$ Vt. Ran | R$_{47}$ Wisc. Ran | D$_{49}$ W.Virginia (sp) Retired |
| R$_{38}$ Kan. Ran | R$_{37}$ Iowa Ran | R$_{36}$ Ind. Ran | R$_{35}$ Ill. Ran | R$_{34}$ Idaho Ran | R$_{33}$ Conn. Ran | R$_{32}$ Colo. Retired | R$_{31}$ California Ran | R$_{30}$ | R$_{29}$ |
| R$_{19}$ | R$_{20}$ | R$_{21}$ | R$_{22}$ | R$_{23}$ | R$_{24}$ | R$_{25}$ | R$_{26}$ | R$_{27}$ | R$_{28}$ |
| R$_{18}$ | R$_{17}$ | R$_{16}$ | R$_{15}$ | R$_{14}$ | R$_{13}$ | R$_{12}$ | R$_{11}$ | R$_{10}$ | R$_9$ |
| | | R$_1$ | R$_2$ | R$_3$ | R$_4$ | R$_5$ | R$_6$ | R$_7$ | R$_8$ |

### Elections results

| | | D$_1$ | D$_2$ | D$_3$ | D$_4$ | D$_5$ | D$_6$ | D$_7$ | D$_8$ |
| D$_{18}$ | D$_{17}$ | D$_{16}$ | D$_{15}$ | D$_{14}$ | D$_{13}$ | D$_{12}$ | D$_{11}$ | D$_{10}$ | D$_9$ |
| D$_{19}$ | D$_{20}$ | D$_{21}$ | D$_{22}$ | D$_{23}$ | D$_{24}$ | D$_{25}$ | D$_{26}$ | D$_{27}$ | D$_{28}$ |
| D$_{38}$ Mo. Re-elected | D$_{37}$ La. Re-elected | D$_{36}$ Ga. Hold | D$_{35}$ Florida Re-elected | D$_{34}$ Ark. Re-elected | D$_{33}$ Ariz. Re-elected | D$_{32}$ Ala. Re-elected | D$_{31}$ | D$_{30}$ | D$_{29}$ |
| D$_{39}$ Nev. Re-elected | D$_{40}$ N.C. Re-elected | D$_{41}$ Okla. Re-elected | D$_{42}$ Ore. Re-elected | D$_{43}$ S.C. (reg) Re-elected | D$_{44}$ S.C. (sp) Hold | D$_{45}$ Washington Re-elected | D$_{46}$ Colo. Gain | D$_{47}$ Idaho Gain | D$_{48}$ Ohio Gain |
| Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | Majority → | D$_{49}$ Pa. Gain |
| R$_{39}$ N.D. Re-elected | R$_{40}$ S.D. Re-elected | R$_{41}$ Utah Re-elected | R$_{42}$ Vt. Re-elected | R$_{43}$ Wisc. Re-elected | R$_{44}$ Ky. (reg) Gain | R$_{45}$ Ky. (sp) Gain | R$_{46}$ N.Y. Gain | R$_{47}$ W.Virginia (sp) Gain | D$_{49}$ Pa. Gain |
| R$_{38}$ N.H. Re-elected | R$_{37}$ Maryland Re-elected | R$_{36}$ Kan. Re-elected | R$_{35}$ Iowa Re-elected | R$_{34}$ Ind. Re-elected | R$_{33}$ Ill. Re-elected | R$_{32}$ Conn. Re-elected | R$_{31}$ California Re-elected | R$_{30}$ | R$_{29}$ |
| R$_{19}$ | R$_{20}$ | R$_{21}$ | R$_{22}$ | R$_{23}$ | R$_{24}$ | R$_{25}$ | R$_{26}$ | R$_{27}$ | R$_{28}$ |
| R$_{18}$ | R$_{17}$ | R$_{16}$ | R$_{15}$ | R$_{14}$ | R$_{13}$ | R$_{12}$ | R$_{11}$ | R$_{10}$ | R$_9$ |
| | | R$_1$ | R$_2$ | R$_3$ | R$_4$ | R$_5$ | R$_6$ | R$_7$ | R$_8$ |
| Key | D$_#$ Democratic R$_#$ Republican |

## Race summaries
### Special elections during the 84th Congress

In these special elections, the winners were seated during 1956 or in 1957 before January 3; ordered by election date, then state.
| State | Incumbent | Incumbent | Incumbent | Results | Candidates |
| State | Senator | Party | Electoral history | Results | Candidates |
| Kentucky (Class 2) | Robert Humphreys | Democratic | 1956 (Appointed) | Interim appointee retired. New senator elected November 6, 1956. Republican gain. | ▌Y John Sherman Cooper (Republican) 53.2% ▌Lawrence Wetherby (Democratic) 46.8% |
| South Carolina (Class 2) | Thomas A. Wofford | Democratic | 1956 (Appointed) | Interim appointee retired. New senator elected November 6, 1956. Democratic hold. | ▌Y Strom Thurmond (Democratic) Unopposed |
| West Virginia (Class 1) | William Laird III | Democratic | 1956 (Appointed) | Interim appointee retired. New senator elected November 6, 1956. Republican gain. | ▌Y Chapman Revercomb (Republican) 53.7% ▌William C. Marland (Democratic) 46.3% |

### Races leading to the 85th Congress

In these regular elections, the winners were elected for the term beginning January 3, 1957; ordered by state.
All of the elections involved the Class 3 seats.
| State | Incumbent | Incumbent | Incumbent | Results | Candidates |
| State | Senator | Party | Electoral history | Results | Candidates |
| Alabama | J. Lister Hill | Democratic | 1938 (Appointed) 1938 1944 1950 | Incumbent re-elected. | ▌Y J. Lister Hill (Democratic) Unopposed |
| Arizona | Carl Hayden | Democratic | 1926 1932 1938 1944 1950 | Incumbent re-elected. | ▌Y Carl Hayden (Democratic) 61.4% ▌Ross F. Jones (Republican) 38.6% |
| Arkansas | J. William Fulbright | Democratic | 1944 1950 | Incumbent re-elected. | ▌Y J. William Fulbright (Democratic) 83.0% ▌Ben C. Henley (Republican) 17.0% |
| California | Thomas Kuchel | Republican | 1953 (Appointed) 1954 (special) | Incumbent re-elected. | ▌Y Thomas Kuchel (Republican) 54.0% ▌Richard Richards (Democratic) 45.6% ▌Ray Gourley (Prohibition) 0.4% |
| Colorado | Eugene Millikin | Republican | 1941 (Appointed) 1942 (special) 1944 1950 | Incumbent retired. New senator elected. Democratic gain. | ▌Y John A. Carroll (Democratic) 50.2% ▌Daniel I. J. Thornton (Republican) 49.8% |
| Connecticut | Prescott Bush | Republican | 1952 (special) | Incumbent re-elected. | ▌Y Prescott Bush (Republican) 54.8% ▌Thomas J. Dodd (Democratic) 43.1% |
| Florida | George Smathers | Democratic | 1950 | Incumbent re-elected. | ▌Y George Smathers (Democratic) Unopposed |
| Georgia | Walter F. George | Democratic | 1922 (special) 1926 1932 1938 1944 1950 | Incumbent retired. New senator elected. Democratic hold. | ▌Y Herman Talmadge (Democratic) Unopposed |
| Idaho | Herman Welker | Republican | 1950 | Incumbent lost re-election. New senator elected. Democratic gain. | ▌Y Frank Church (Democratic) 56.2% ▌Herman Welker (Republican) 38.7% |
| Illinois | Everett Dirksen | Republican | 1950 | Incumbent re-elected. | ▌Y Everett Dirksen (Republican) 54.1% ▌Richard Stengel (Democratic) 45.7% |
| Indiana | Homer E. Capehart | Republican | 1944 1950 | Incumbent re-elected. | ▌Y Homer E. Capehart (Republican) 55.2% ▌Claude R. Wickard (Democratic) 44.4% |
| Iowa | Bourke B. Hickenlooper | Republican | 1944 1950 | Incumbent re-elected. | ▌Y Bourke B. Hickenlooper (Republican) 53.9% ▌R. M. Evans (Democratic) 46.1% |
| Kansas | Frank Carlson | Republican | 1950 (special) 1950 | Incumbent re-elected. | ▌Y Frank Carlson (Republican) 57.9% ▌George Hart (Democratic) 40.5% |
| Kentucky | Earle Clements | Democratic | 1950 (special) 1950 | Incumbent lost re-election. New senator elected. Republican gain. | ▌Y Thruston Ballard Morton (Republican) 50.4% ▌Earle Clements (Democratic) 49.6% |
| Louisiana | Russell B. Long | Democratic | 1948 (special) 1950 | Incumbent re-elected. | ▌Y Russell B. Long (Democratic) Unopposed |
| Maryland | John Marshall Butler | Republican | 1950 | Incumbent re-elected. | ▌Y John Marshall Butler (Republican) 53.0% ▌George P. Mahoney (Democratic) 47.0% |
| Missouri | Thomas C. Hennings Jr. | Democratic | 1950 | Incumbent re-elected. | ▌Y Thomas C. Hennings Jr. (Democratic) 56.4% ▌Herbert Douglas (Republican) 43.6% |
| Nevada | Alan Bible | Democratic | 1954 (special) | Incumbent re-elected. | ▌Y Alan Bible (Democratic) 52.6% ▌Clarence Clifton Young (Republican) 47.4% |
| New Hampshire | Norris Cotton | Republican | 1954 (special) | Incumbent re-elected. | ▌Y Norris Cotton (Republican) 64.1% ▌Laurence M. Pickett (Democratic) 35.9% |
| New York | Herbert H. Lehman | Democratic | 1949 (special) 1950 | Incumbent retired. New senator elected. Republican gain. Winner delayed term until January 9, 1957, when he resigned his post as an Attorney General of New York. | ▌Y Jacob Javits (Republican) 53.3% ▌Robert F. Wagner Jr. (Democratic) 46.7% |
| North Carolina | Sam Ervin | Democratic | 1954 (Appointed) 1954 (special) | Incumbent re-elected. | ▌Y Sam Ervin (Democratic) 66.6% ▌Joel A. Johnson (Republican) 33.4% |
| North Dakota | Milton Young | Republican | 1945 (Appointed) 1946 (special) 1950 | Incumbent re-elected. | ▌Y Milton Young (Republican) 63.6% ▌Quentin Burdick (Democratic-NPL) 36.0% |
| Ohio | George H. Bender | Republican | 1954 (special) | Incumbent lost re-election. New senator elected. Democratic gain. | ▌Y Frank Lausche (Democratic) 52.9% ▌George H. Bender (Republican) 47.1% |
| Oklahoma | Mike Monroney | Democratic | 1950 | Incumbent re-elected. | ▌Y Mike Monroney (Democratic) 55.4% ▌Douglas McKeever (Republican) 44.7% |
| Oregon | Wayne Morse | Democratic | 1944 1950 | Incumbent re-elected. | ▌Y Wayne Morse (Democratic) 54.2% ▌Douglas McKay (Republican) 45.8% |
| Pennsylvania | James H. Duff | Republican | 1950 | Incumbent lost re-election. New senator elected. Democratic gain. | ▌Y Joseph S. Clark Jr. (Democratic) 50.1% ▌James H. Duff (Republican) 49.7% |
| South Carolina | Olin D. Johnston | Democratic | 1944 1950 | Incumbent re-elected. | ▌Y Olin D. Johnston (Democratic) Unopposed |
| South Dakota | Francis Case | Republican | 1950 | Incumbent re-elected. | ▌Y Francis Case (Republican) 50.8% ▌Kenneth Holum (Democratic) 49.2% |
| Utah | Wallace F. Bennett | Republican | 1950 | Incumbent re-elected. | ▌Y Wallace F. Bennett (Republican) 54.0% ▌Alonzo F. Hopkin (Democratic) 46.0% |
| Vermont | George Aiken | Republican | 1940 (special) 1944 1950 | Incumbent re-elected. | ▌Y George Aiken (Republican) 66.4% ▌Bernard G. O'Shea (Democratic) 33.6% |
| Washington | Warren Magnuson | Democratic | 1944 (Appointed) 1944 1950 | Incumbent re-elected. | ▌Y Warren Magnuson (Democratic) 61.1% ▌Arthur B. Langlie (Republican) 38.9% |
| Wisconsin | Alexander Wiley | Republican | 1938 1944 1950 | Incumbent re-elected. | ▌Y Alexander Wiley (Republican) 58.6% ▌Henry Maier (Democratic) 41.2% |

## Closest races

Fifteen races had a margin of victory under 10%:
| State | Party of winner | Margin |
| Colorado | Democratic (flip) | 0.4% |
| Pennsylvania | Democratic (flip) | 0.4% |
| Kentucky | Republican (flip) | 0.8% |
| South Dakota | Republican | 1.6% |
| Nevada | Democratic | 5.2% |
| Ohio | Democratic | 5.8% |
| Maryland | Republican | 6.0% |
| Kentucky (special) | Republican (flip) | 6.4% |
| New York | Republican (flip) | 6.6% |
| West Virginia (special) | Republican (flip) | 7.4% |
| Iowa | Republican | 7.8% |
| Utah | Republican | 8.0% |
| California | Republican | 8.34% |
| Illinois | Republican | 8.39% |
| Oregon | Democratic | 8.4% |

## Alabama

United States Senate election in Alabama of 1956 :
| Party | Party | Candidate | Votes | % |
| | Democratic | J. Lister Hill (Incumbent) | 330,182 | 100.00 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Arizona

1956 United States Senate election in Arizona :
| Party | Party | Candidate | Votes | % |
| | Democratic | Carl Hayden (Incumbent) | 170,816 | 61.39 |
| | Republican | Ross F. Jones | 107,447 | 38.61 |
| Majority | Majority | Majority | 63,369 | 22.78 |
| Turnout | Turnout | Turnout | 278,263 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Arkansas

1956 United States Senate election in Arkansas :
| Party | Party | Candidate | Votes | % |
| | Democratic | J. William Fulbright (Incumbent) | 331,689 | 82.98 |
| | Republican | Ben C. Henley | 68,016 | 17.02 |
| Majority | Majority | Majority | 263,673 | 65.96 |
| Turnout | Turnout | Turnout | 399,705 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## California

1956 United States Senate election in California :
| Party | Party | Candidate | Votes | % |
| | Republican | Thomas Kuchel (Incumbent) | 2,892,918 | 53.96 |
| | Democratic | Richard Richards | 2,445,816 | 45.62 |
| | Prohibition | Ray Gourley | 22,410 | 0.42 |
| | None | Scattering | 323 | 0.01 |
| Majority | Majority | Majority | 447,102 | 8.34 |
| Turnout | Turnout | Turnout | 5,361,467 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Colorado

1956 United States Senate election in Colorado :
| Party | Party | Candidate | Votes | % |
| | Democratic | John A. Carroll | 319,872 | 50.22 |
| | Republican | Dan Thornton | 317,102 | 49.78 |
| Majority | Majority | Majority | 2,770 | 0.44 |
| Turnout | Turnout | Turnout | 636,974 | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## Connecticut

1956 United States Senate election in Connecticut :
| Party | Party | Candidate | Votes | % |
| | Republican | Prescott Bush (Incumbent) | 610,829 | 54.84 |
| | Democratic | Thomas J. Dodd | 479,460 | 43.05 |
| | Independent Republican | Suzanne S. Stevenson | 10,199 | 0.92 |
| | Socialist | Jasper McLevy | 7,079 | 0.64 |
| | Write-In | Vivien Kellems | 6,219 | 0.56 |
| | None | Scattering | 33 | 0.00 |
| Majority | Majority | Majority | 131,369 | 11.79 |
| Turnout | Turnout | Turnout | 1,113,819 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Florida

1956 United States Senate election in Florida :
| Party | Party | Candidate | Votes | % |
| | Democratic | George A. Smathers (incumbent) | 655,418 | 100.00 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Georgia

1956 United States Senate election in Georgia :
| Party | Party | Candidate | Votes | % |
| | Democratic | Herman Talmadge | 541,094 | 99.97 |
| | None | Scattering | 173 | 0.03 |
| Majority | Majority | Majority | 540,921 | 99.94 |
| Turnout | Turnout | Turnout | 541,267 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Idaho

1956 United States Senate election in Idaho :
| Party | Party | Candidate | Votes | % |
| | Democratic | Frank Church | 149,096 | 56.20 |
| | Republican | Herman Welker (Incumbent) | 102,781 | 38.74 |
| | Write-in | Glen Taylor | 13,415 | 5.06 |
| Majority | Majority | Majority | 46,315 | 17.46 |
| Turnout | Turnout | Turnout | 265,292 | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## Illinois

1956 United States Senate election in Illinois :
| Party | Party | Candidate | Votes | % |
| | Republican | Everett Dirksen (Incumbent) | 2,307,352 | 54.10 |
| | Democratic | Richard Stengel | 1,949,883 | 45.72 |
| | Socialist Labor | Louis Fisher | 7,587 | 0.18 |
| | None | Scattering | 8 | 0.00 |
| Majority | Majority | Majority | 357,469 | 8.38 |
| Turnout | Turnout | Turnout | 4,264,830 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Indiana

1956 United States Senate election in Indiana :
| Party | Party | Candidate | Votes | % |
| | Republican | Homer Capehart (Incumbent) | 1,084,262 | 55.20 |
| | Democratic | Claude R. Wickard | 871,781 | 44.39 |
| | Prohibition | Carl W. Thompson | 6,685 | 0.34 |
| | Socialist Labor | Gordon A. Long | 1,258 | 0.06 |
| Majority | Majority | Majority | 212,481 | 10.81 |
| Turnout | Turnout | Turnout | 1,963,986 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Iowa

1956 United States Senate election in Iowa :
| Party | Party | Candidate | Votes | % |
| | Republican | Bourke B. Hickenlooper (Incumbent) | 635,499 | 53.92 |
| | Democratic | Rudolph M. Evans | 543,156 | 46.08 |
| Majority | Majority | Majority | 92,343 | 7.84 |
| Turnout | Turnout | Turnout | 1,178,655 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Kansas

1956 United States Senate election in Kansas :
| Party | Party | Candidate | Votes | % |
| | Republican | Frank Carlson (Incumbent) | 477,822 | 57.90 |
| | Democratic | George Hart | 333,939 | 40.46 |
| | Prohibition | C. Floyd Hester | 13,519 | 1.64 |
| Majority | Majority | Majority | 143,883 | 17.44 |
| Turnout | Turnout | Turnout | 825,280 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Kentucky

Two elections in Kentucky converted both seats from Democratic to Republican. As a result, this marked the first time since 1916 that both Senate seats in a state flipped from one party to the other in a single election cycle.

### Kentucky (special)

Following the death of Alben Barkley on April 30, 1956, Robert Humphreys was appointed June 21, 1956 to continue the term, pending a special election. Humphreys did not run in the special election to finish the term that would end in 1961.
Republican former-senator John Sherman Cooper, who had twice won special elections to that seat in 1946 and 1952, was again elected to finish the term.
1956 United States Senate special election in Kentucky :
| Party | Party | Candidate | Votes | % |
| | Republican | John Sherman Cooper | 538,505 | 53.23 |
| | Democratic | Lawrence W. Wetherby | 473,140 | 46.77 |
| Majority | Majority | Majority | 65,365 | 6.46 |
| Turnout | Turnout | Turnout | 1,011,645 | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |
This time, however, Cooper would be re-elected in 1960 and again in 1966, serving until his 1973 retirement.

### Kentucky (regular)

First-term Democrat Earle Clements lost re-election to Republican Thruston B. Morton, who was Eisenhower's Assistant Secretary of State for Legislative Affairs.
1956 United States Senate election in Kentucky :
| Party | Party | Candidate | Votes | % |
| | Republican | Thruston B. Morton | 506,903 | 50.35 |
| | Democratic | Earle Clements (Incumbent) | 499,922 | 49.65 |
| Majority | Majority | Majority | 6,981 | 0.70 |
| Turnout | Turnout | Turnout | 1,006,825 | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Louisiana

1956 United States Senate election in Louisiana :
| Party | Party | Candidate | Votes | % |
| | Democratic | Russell Long (Incumbent) | 335,564 | 100.00 |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Maryland

1956 United States Senate election in Maryland :
| Party | Party | Candidate | Votes | % |
| | Republican | John Marshall Butler (Incumbent) | 473,059 | 52.96 |
| | Democratic | George P. Mahoney | 420,108 | 47.04 |
| Majority | Majority | Majority | 52,951 | 5.92 |
| Turnout | Turnout | Turnout | 893,167 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Missouri

1956 United States Senate election in Missouri :
| Party | Party | Candidate | Votes | % |
| | Democratic | Thomas C. Hennings Jr. (Incumbent) | 1,015,936 | 56.41 |
| | Republican | Herbert Douglas | 785,048 | 43.59 |
| Majority | Majority | Majority | 230,888 | 12.82 |
| Turnout | Turnout | Turnout | 1,800,984 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Nevada

1956 United States Senate election in Nevada :
| Party | Party | Candidate | Votes | % |
| | Democratic | Alan Bible (Incumbent) | 50,677 | 52.58 |
| | Republican | Cliff Young | 45,712 | 47.42 |
| Majority | Majority | Majority | 4,965 | 5.16 |
| Turnout | Turnout | Turnout | 96,389 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## New Hampshire

1956 United States Senate election in New Hampshire :
| Party | Party | Candidate | Votes | % |
| | Republican | Norris Cotton (Incumbent) | 161,424 | 64.07 |
| | Democratic | Laurence M. Pickett | 90,519 | 35.93 |
| Majority | Majority | Majority | 70,905 | 28.14 |
| Turnout | Turnout | Turnout | 251,943 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## New York

In New York, the Republican state convention met on September 10 at Albany, New York, and nominated New York State Attorney General Jacob K. Javits. The Democratic state convention met on September 10 at Albany, New York, and nominated Mayor of New York City Robert F. Wagner Jr., for the U.S. Senate. The Liberal Party endorsed the Democratic nominee, Mayor Robert F. Wagner Jr., for the U.S. Senate. On October 1, a movement was launched to vote for General of the Army Douglas MacArthur as a write-in candidate for the U.S. Senate. On October 2, MacArthur disavowed the campaign, and stated that he was not a candidate.
The Republican candidate was elected.
1956 United States Senate election in New York :
| Party | Party | Candidate | Votes | % |
| | Republican | Jacob Javits | 3,723,933 | 53.26 |
| | Democratic | Robert F. Wagner Jr. | 3,265,159 | 46.70 |
| | None | Scattering | 1,390 | 0.02 |
| | None | Miscellaneous | 654 | 0.01 |
| Majority | Majority | Majority | 458,774 | 6.56 |
| Turnout | Turnout | Turnout | 6,991,136 | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## North Carolina

1956 United States Senate election in North Carolina :
| Party | Party | Candidate | Votes | % |
| | Democratic | Samuel J. Ervin Jr. (Incumbent) | 731,433 | 66.56 |
| | Republican | Joel A. Johnson | 367,475 | 33.44 |
| Majority | Majority | Majority | 363,958 | 33.12 |
| Turnout | Turnout | Turnout | 1,098,908 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## North Dakota

In North Dakota, the incumbent, Republican Milton Young, sought and received re-election to his third term, defeating North Dakota Democratic-NPL Party candidate Quentin N. Burdick, son of North Dakota congressman Usher L. Burdick.
Only Young filed as a Republican, and the endorsed Democratic candidate was Quentin Burdick, the son of well-known politician Usher Burdick, and former candidate for Governor of North Dakota. Young and Burdick won the primary elections for their respective parties.
One independent candidate, Arthur C. Townley, also filed before the deadline. Townley would later seek the state's other senate seat in 1958, and was known for creating the National Non-Partisan League.
1956 United States Senate election in North Dakota :
| Party | Party | Candidate | Votes | % |
| | Republican | Milton R. Young (incumbent) | 155,305 | 63.61 |
| | Democratic–NPL | Quentin N. Burdick | 87,919 | 36.01 |
| | Independent | Arthur C. Townley | 937 | 0.38 |
| Majority | Majority | Majority | 67,386 | 27.60 |
| Turnout | Turnout | Turnout | 244,161 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Ohio

1956 United States Senate election in Ohio :
| Party | Party | Candidate | Votes | % |
| | Democratic | Frank J. Lausche | 1,864,589 | 52.89 |
| | Republican | George H. Bender (Incumbent) | 1,660,910 | 47.11 |
| Majority | Majority | Majority | 203,679 | 5.78 |
| Turnout | Turnout | Turnout | 3,525,499 | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## Oklahoma

1956 United States Senate election in Oklahoma :
| Party | Party | Candidate | Votes | % |
| | Democratic | Mike Monroney (Incumbent) | 459,996 | 55.35 |
| | Republican | Douglas McKeever | 371,146 | 44.65 |
| Majority | Majority | Majority | 88,850 | 10.70 |
| Turnout | Turnout | Turnout | 831,142 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Oregon

In Oregon, Republican-turned-Independent-turned-Democrat Wayne Morse decided to seek re-election for his first full term as a Democrat. Morse defeated Republican candidate Douglas McKay in the hotly contested general election.
1956 Oregon United States Senate election :
| Party | Party | Candidate | Votes | % |
| | Democratic | Wayne Morse, Incumbent Senator since 1945; Democratic party since 1955 | 396,849 | 54.20 |
| | Republican | Douglas McKay, former Governor of Oregon (1949–1952) and United States Secretary of the Interior (1953–1956) | 335,405 | 45.80 |
| Majority | Majority | Majority | 61,444 | 8.39 |
| Turnout | Turnout | Turnout | 732,254 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## Pennsylvania

In Pennsylvania, incumbent Republican U.S. senator James H. Duff sought re-election to another term, but was defeated by the Democratic nominee, Joseph S. Clark Jr.
General election results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Joseph S. Clark Jr. Former Mayor of Philadelphia | 2,268,641 | 50.08 |
| | Republican | James H. Duff Incumbent U.S. senator | 2,250,671 | 49.69 |
| | Socialist Labor | George S. Taylor | 7,447 | 0.16 |
| | Militant Workers | Herbert G. Lewin | 2,035 | 0.05 |
| Majority | Majority | Majority | 17,970 | 0.39 |
| Turnout | Turnout | Turnout | 4,529,874 | |
| | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican | Democratic gain from Republican |

## South Carolina

In South Carolina the regular election was held simultaneously with the special election.

### South Carolina (regular)

Incumbent Democrat Olin D. Johnston handily defeated Republican mayor of Clemson Leon P. Crawford. Olin D. Johnston, the incumbent Senator, faced no opposition from South Carolina Democrats and avoided a primary election. Leon P. Crawford, the mayor of the town of Clemson in the Upstate, faced no opposition from South Carolina Republicans and avoided a primary election. Crawford campaigned as a defender of states' rights and denounced Johnston for backing the New Deal and the Fair Deal. The state Republican Party believed that Crawford could have a chance in the election if he galvanized the 128,000 registered black voters, although they were weary of being labeled as the black party. In the end, Johnston remained highly popular with the voters who were still leery of the Republican party and he easily defeated Crawford in the general election.
South Carolina U.S. Senate Election, 1956 :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Olin D. Johnston (Incumbent) | 230,150 | 82.21 | −17.69% |
| | Republican | Leon P. Crawford | 49,695 | 17.75 | +17.75% |
| | Write-in | Write-Ins | 124 | 0.04 | −0.1% |
| Majority | Majority | Majority | 180,455 | 64.46 | −35.34% |
| Turnout | Turnout | Turnout | 279,969 | 36.8 | |
| | Democratic hold | Democratic hold | Swing | | |

### South Carolina (special)

The special election resulted from the resignation of Senator Strom Thurmond on April 4, 1956, who was keeping a campaign pledge he had made in the 1954 election. Thurmond was unopposed in his bid to complete the remaining four years of the term. Senator Strom Thurmond faced no opposition from South Carolina Democrats and avoided a primary election. There was a possibility that Governor George Bell Timmerman Jr. might enter the race, but Thurmond was held in such high regard by the voters that there would have been no chance of defeating Thurmond. With no challenge to the remainder of the term, Thurmond did not conduct a campaign and rejoined his old law firm in Aiken until he returned to the Senate after the general election.
South Carolina U.S. Senate Special Election, 1956 :
| Party | Party | Candidate | Votes | % | ±% |
| | Democratic | Strom Thurmond | 245,371 | 100.0 | +36.9% |
| Majority | Majority | Majority | 245,371 | 100.0 | +73.7% |
| Turnout | Turnout | Turnout | 245,371 | 32.2 | +5.9% |
| | Democratic hold | Democratic hold | Swing | | |

## South Dakota

1956 United States Senate election in South Dakota :
| Party | Party | Candidate | Votes | % |
| | Republican | Francis Case (Incumbent) | 147,621 | 50.79 |
| | Democratic | Kenneth Holum | 143,001 | 49.21 |
| Majority | Majority | Majority | 4,620 | 1.58 |
| Turnout | Turnout | Turnout | 290,622 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Utah

1956 United States Senate election in Utah :
| Party | Party | Candidate | Votes | % |
| | Republican | Wallace F. Bennett (Incumbent) | 178,261 | 53.96 |
| | Democratic | Alonzo F. Hopkin | 152,120 | 46.04 |
| Majority | Majority | Majority | 26,141 | 7.92 |
| Turnout | Turnout | Turnout | 330,381 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Vermont

In Vermont, incumbent Republican George Aiken ran successfully for re-election to another term in the United States Senate, defeating Democratic challenger Bernard G. O'Shea.
Republican primary results :
| Party | Party | Candidate | Votes | % |
| | Republican | George Aiken (Incumbent) | 49,454 | 99.9 |
| | Republican | Other | 27 | 0.1 |
| Total votes | Total votes | Total votes | 49,481 | 100 |
Democratic primary results :
| Party | Party | Candidate | Votes | % |
| | Democratic | Bernard G. O'Shea | 7,997 | 99.8 |
| | Democratic | Other | 19 | 0.2 |
| Total votes | Total votes | Total votes | 801 | 100 |
1956 United States Senate election in Vermont :
| Party | Party | Candidate | Votes | % |
| | Republican | George Aiken (Incumbent) | 103,101 | 66.39 |
| | Democratic | Bernard G. O'Shea | 52,184 | 33.60 |
| | None | Scattering | 4 | 0.00 |
| Majority | Majority | Majority | 50,917 | 32.79 |
| Turnout | Turnout | Turnout | 155,289 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |

## Washington

1956 United States Senate election in Washington :
| Party | Party | Candidate | Votes | % |
| | Democratic | Warren G. Magnuson (Incumbent) | 685,565 | 61.09 |
| | Republican | Arthur B. Langlie | 436,652 | 38.91 |
| Majority | Majority | Majority | 248,913 | 22.18 |
| Turnout | Turnout | Turnout | 1,122,217 | |
| | Democratic hold | Democratic hold | Democratic hold | Democratic hold |

## West Virginia (special)

Following the death of Harley M. Kilgore on February 28, 1956, William Laird III was appointed to fill this seat and assumed office on March 13, 1956. Laird did not opt to run in the special election to fill the remainder of Kilgore's term through the end of the 85th Congress on January 3, 1959. This was the last time until 2014 that the Republicans won a U.S. Senate election in the state and the last time until 2024 that they won the Class I seat.
1956 United States Senate election in West Virginia :
| Party | Party | Candidate | Votes | % |
| | Republican | William Chapman Revercomb | 432,123 | 53.67 |
| | Democratic | William C. Marland | 373,051 | 46.33 |
| Majority | Majority | Majority | 59,072 | 7.34 |
| Turnout | Turnout | Turnout | 805,174 | |
| | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic | Republican gain from Democratic |

## Wisconsin

Incumbent Republican Senator Alexander Wiley easily won reelection to a fourth and final term, defeating the Democratic candidate, Henry W. Maier, by a margin of 17.4%. This would be the last time a Republican would win a Senate race in Wisconsin until Bob Kasten in 1980, and the last time a Republican would win more than 2 terms until Ron Johnson's victory in 2022.
1956 United States Senate election in Wisconsin :
| Party | Party | Candidate | Votes | % |
| | Republican | Alexander Wiley (Incumbent) | 892,473 | 58.59 |
| | Democratic | Henry W. Maier | 627,903 | 41.22 |
| | Independent | Walter Semrau | 2,745 | 0.18 |
| | None | Scattering | 235 | 0.02 |
| Majority | Majority | Majority | 264,570 | 17.37 |
| Turnout | Turnout | Turnout | 1,523,356 | |
| | Republican hold | Republican hold | Republican hold | Republican hold |