Michael Joseph Mansfield was an American Democratic Party politician and diplomat who represented Montana in the United States House of Representatives from 1943 to 1953 and United States Senate from 1953 to 1977. As the leader of the Senate Democratic Caucus from 1961 to 1977, Mansfield shepherded Great Society programs through the Senate; his tenure of exactly sixteen years was the longest of any party leader in Senate history, until the record was broken by Mitch McConnell in 2023.
The 1984 United States Senate elections were held on November 6, with the 33 seats of Class 2 contested in regular elections. They coincided with the landslide re-election of President Ronald Reagan in the presidential election. In spite of the lopsided presidential race, Reagan's Republican Party suffered a net loss of two Senate seats to the Democrats, although it retained control of the Senate with a reduced 53–47 majority. Democrats defeated incumbents in Illinois and Iowa, and won an open seat in Tennessee, while Republicans defeated an incumbent in Kentucky.
The 1978 United States Senate elections were held on November 7, in the middle of Democratic President Jimmy Carter's term. The 33 seats of Class 2 were contested in regular elections. Special elections were also held to fill vacancies.
The 1976 United States Senate elections was an election for the United States Senate. Held on November 2, the 33 seats of Class 1 were contested in regular elections. They coincided with Democrat Jimmy Carter's presidential election and the United States Bicentennial celebration. Although almost half of the seats decided in this election changed parties, Carter's narrow victory did not provide coattails for the Democratic Party. Each party flipped seven Senate seats, although, one of the seats flipped by Democrats was previously held by a Conservative.
The 1972 United States Senate elections were held on November 7, with the 33 seats of Class 2 contested in regular elections. They coincided with the landslide re-election of Republican President Richard Nixon. Despite Nixon's landslide victory, Democrats increased their majority by two seats. The Democrats picked up open seats in Kentucky and South Dakota, and defeated four incumbent senators: Gordon Allott of Colorado, J. Caleb Boggs of Delaware, Jack Miller of Iowa, and Margaret Chase Smith of Maine. The Republicans picked up open seats in New Mexico, North Carolina, and Oklahoma, and defeated one incumbent, William B. Spong Jr. of Virginia.
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 2008 United States elections were held on Tuesday, November 4, 2008, during the war on terror and the onset of the Great Recession. It was considered a Democratic wave election, with Democratic Senator Barack Obama of Illinois defeating Senator John McCain of Arizona by a wide margin, and the Democrats bolstering their majorities in both chambers of Congress, thereby marking the first time since 1992 in which the Democrats won Congress and the presidency in one election.
The 1930 United States Senate election in Montana took place on November 4, 1930. Incumbent United States Senator Thomas J. Walsh, who was first elected to the Senate in 1912, and re-elected in 1918 and 1924, ran for re-election. He won the Democratic primary unopposed, and faced Montana Supreme Court Associate Justice Albert J. Galen, the Republican nominee, and several independent opponents in the general election. Ultimately, Walsh defeated his opponents in a landslide and won his fourth and final term in the Senate.
The 1930 United States Senate election in Montana took place on November 3, 1936. Incumbent United States Senator James E. Murray, who was first elected to the Senate in a special election in 1934, ran for re-election. He narrowly emerged from a competitive and close Democratic primary, wherein he was challenged by United States Congressman Joseph P. Monaghan, who represented Montana's 1st congressional district. In the general election, Murray was opposed by Thomas O. Larson, a State Senator and the Republican nominee, and Monaghan, who, after losing the primary, ran as an independent candidate. Murray ended up winning a second term, and his first full term, in a landslide, defeating both of his opponents by a comfortable margin.
The 1990 United States Senate election in Montana took place on November 6, 1990. Incumbent United States Senator Max Baucus, who was first elected in 1978 and was re-elected in 1984, ran for re-election. After winning the Democratic primary, he moved on to the general election, where he was opposed by Allen Kolstad, the Lieutenant Governor of Montana and the Republican nominee. Baucus ultimately ended up defeating Kolstad in a landslide, winning his third term with ease.
The 1922 United States Senate election in Montana took place on November 7, 1922. Incumbent United States Senator Henry L. Myers, who was first elected to the Senate in 1910, and was re-elected in 1916, declined to seek re-election. Former United States Attorney Burton K. Wheeler won the Democratic primary and advanced to the general election, where he faced Carl W. Riddick, the United States Congressman from Montana's 2nd congressional district and the Republican nominee. Ultimately, Wheeler defeated Riddick comfortably and won his first term in the Senate.
The 1934 United States Senate election in Montana took place on November 6, 1934. Incumbent United States Senator Burton K. Wheeler, who was first elected to the Senate in 1922, and was re-elected in 1928, ran for re-election. After easily winning the Democratic primary, Wheeler moved on to the general election, where he faced George M. Bourquin, a former United States Federal Judge and the Republican nominee. In a stark contrast to his close campaign in 1928, Wheeler won re-election to his third Senate term in a landslide.
The 1940 United States Senate election in Montana took place on November 5, 1940. Incumbent United States Senator Burton K. Wheeler, who was first elected to the Senate in 1922, and was re-elected in 1928 and 1934, ran for re-election. Though he faced a serious challenger in the Democratic primary, he emerged victorious, and advanced to the general election, where he faced E. K. Cheadle, a state district judge and the Republican nominee. Just like in 1934, Wheeler won re-election in a landslide, winning his fourth term in the Senate.
The 1952 United States Senate election in Montana took place on November 4, 1952. Incumbent United States Senator Zales Ecton, who was first elected to the Senate in 1946, ran for re-election. Ecton won the Republican primary uncontested, and advanced to the general election, where he faced Mike Mansfield, the United States Congressman from Montana's 1st congressional district and the Democratic nominee. Following a close campaign, Mansfield narrowly defeated Ecton, winning his first of several terms in the Senate.
The 1958 United States Senate election in Montana took place on November 4, 1958. Incumbent United States Senator Mike Mansfield, who was first elected to the Senate in 1952, ran for re-election. Mansfield won the Democratic primary comfortably, and moved on to the general election, where he was opposed by Lou W. Welch, a millworker and the Republican nominee. In contrast to the close campaign in 1952, Mansfield defeated Welch in a landslide and won his second term in the Senate easily.
The 1970 United States Senate election in Montana took place on November 3, 1970. Incumbent U.S. Senator Mike Mansfield, the sitting Senate majority leader who was first elected to the Senate in 1952 and was re-elected in 1958 and 1964, ran for re-election. Mansfield won the Democratic primary against several opponents, and advanced to the general election, where he was opposed by Harold E. Wallace, a sporting goods salesman and the Republican nominee. While his margin of victory decreased slightly from 1964, Mansfield still managed to defeat Wallace in a landslide, winning his fourth and final term in the Senate.
