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.
The 1974 United States Senate elections were held on November 5, with the 34 seats of Class 3 contested in regular elections. They occurred in the wake of the Watergate scandal, Richard M. Nixon's resignation from the presidency, and Gerald Ford's subsequent pardon of Nixon. Economic issues, specifically inflation and stagnation, were also a factor that contributed to Republican losses. As an immediate result of the November 1974 elections, Democrats made a net gain of three seats from the Republicans, as they defeated Republican incumbents in Colorado and Kentucky and picked up open seats in Florida and Vermont, while Republicans won the open seat in Nevada. Following the elections, at the beginning of the 94th U.S. Congress, the Democratic caucus controlled 60 seats, and the Republican caucus controlled 38 seats.
The 1970 United States Senate elections was an election for the United States Senate. It took place on November 3, with the 33 seats of Class 1 contested in regular elections. Special elections were also held to fill vacancies. These races occurred in the middle of Richard Nixon's first term as president. The Democrats lost a net of three seats, while the Republicans and the Conservative Party of New York picked up one net seat each, and former Democrat Harry F. Byrd Jr. was re-elected as an independent.
The 1968 United States Senate elections were elections for the United States Senate. Held on November 5, the 34 seats of Class 3 were contested in regular elections. They coincided with the presidential election of the same year. The Republicans picked up five net seats in the Senate. This saw Republicans win a Senate seat in Florida for the first time since Reconstruction.
The 1964 United States Senate elections were held on November 3. The 33 seats of Class 1 were contested in regular elections. Special elections were also held to fill vacancies. They coincided with the election of President Lyndon B. Johnson by an overwhelming majority, to a full term. His Democratic Party picked up a net two seats from the Republicans. As of 2023, this was the last time either party has had a two-thirds majority in the Senate, which allowed the Senate Democrats to override a veto, propose constitutional amendments, or convict and expel certain officials without any votes from Senate Republicans. However, internal divisions would have prevented the Democrats from having done so. The Senate election cycle coincided with Democratic gains in the House in the same year.
The 1960 United States Senate elections coincided with the election of John F. Kennedy as president on November 8, 1960. The 33 seats of Class 2 were contested in regular elections. A special election was also held on June 28, 1960, for a mid-term vacancy in North Dakota where Democrats flipped a seat to expand their majority to 66–34. As Majority Leader Lyndon Johnson was elected Vice President, Mike Mansfield became the new majority leader.
The 1958 United States Senate elections were elections for the United States Senate which occurred in the middle of President Dwight D. Eisenhower's second term. Thirty-two seats of Class 1 were contested in regular elections, the new state of Alaska held its first Senate elections for its Class 2 and 3 seats, and two special elections were held to fill vacancies.
The 1912–13 United States Senate elections were held on various dates in various states. They were the last U.S. Senate elections before the ratification of the Seventeenth Amendment in 1913, establishing direct elections for all Senate seats. Senators had been primarily chosen by state legislatures. Senators were elected over a wide range of time throughout 1912 and 1913, and a seat may have been filled months late or remained vacant due to legislative deadlock. Some states elected their senators directly even before passage of Seventeenth Amendment. Oregon pioneered direct election and experimented with different measures over several years until it succeeded in 1907. Soon after, Nebraska followed suit and laid the foundation for other states to adopt measures reflecting the people's will. By 1912, as many as 29 states elected senators either as nominees of their party's primary or in conjunction with a general election.
The United States Senate election of 1942 in Massachusetts was held on November 3, 1942. Republican incumbent Henry Cabot Lodge Jr. was re-elected to a second term in office over Democratic U.S. Representative Joseph E. Casey.
The 1986 United States Senate election in California took place on November 4, 1986. Incumbent Democratic U.S. Senator Alan Cranston narrowly won re-election to a fourth and final term over Republican U.S. Congressman Ed Zschau. This was the last time where both major party nominees for the Class 3 Senate seat in California were men until 2022.
The 1994 United States Senate election in Michigan was held November 8, 1994. Incumbent Democratic Senator Don Riegle decided not run for re-election. Spencer Abraham won the open seat, becoming the first and so far only Republican to win a U.S. Senate race in Michigan since Robert P. Griffin in 1972 and the first to win the state's Class I seat since Charles E. Potter in 1952. As of 2024, this is the last time that a man won the Class 1 Senate seat in Michigan.
The 1934 United States Senate election in Tennessee was held on November 5, 1934. Incumbent Democratic Senator Kenneth D. McKellar was re-elected to a fourth term in office, defeating Republican former Governor Ben W. Hooper in a rematch from 1916.
The 1948 United States Senate election in Nebraska took place on November 2, 1948. Senate Majority Whip Kenneth S. Wherry was re-elected to a second term, defeating former Representative Terry Carpenter. He won by a larger margin than 1942, due to the absence of a third party candidate. Wherry overperformed Republican presidential candidate Thomas Dewey by 2.55%, who won the state with 54.15% in the presidential election.
The 1954 United States Senate special election in New Hampshire took place on November 2, 1954, to elect a U.S. Senator to complete the unexpired term of Senator Charles W. Tobey, who died on July 24, 1953. Former President of the New Hampshire Bar Association Robert W. Upton was appointed on August 14, 1953 by Governor Hugh Gregg to fill the vacancy until a special election could be held.
The 1916 United States Senate election in Indiana took place on November 7, 1916. Incumbent Democratic U.S. senator and Senate Majority Leader John W. Kern ran for re-election to a second term in office, he was defeated by Republican Harry New, a former chairman of the Republican National Committee.
The 1924 United States Senate election in Nebraska took place on November 4, 1924. The incumbent Republican, George W. Norris, was re-elected by a wide margin to a third term. He defeated John J. Thomas. Norris overperformed Calvin Coolidge, who won the state with 47.09% in the presidential election.
The 1936 United States Senate election in Nebraska was held on November 3, 1936.
The 1946 United States Senate election in Tennessee was held on November 5, 1946. Incumbent Democratic Senator Kenneth D. McKellar was re-elected to a sixth term in office. He defeated a primary challenge by Edward W. Carmack Jr. and easily won the general election against Republican William B. Ladd, and Independent candidate John Randolph Neal Jr.
Two special elections in Nebraska were held on November 2, 1954, alongside a regular election. The Class I election was to finish Hugh A. Butler's term, with Samuel W. Reynolds appointed to the vacancy on July 3, 1954. The Class II election was to finish Kenneth S. Wherry's term, with Eva Bowring as incumbent at the time of the election. Both seats were held by Republicans, with Roman Hruska winning the Class I election and Hazel Abel winning the Class II election.
The 1970 United States Senate election in California was held on November 3, 1970.
