Elections to the United States House of Representatives for the 109th Congress were held on November 2, 2004. The House of Representatives has 435 seats. It coincided with the reelection of President George W. Bush. In the 108th Congress, Republicans held 227 seats, Democrats held 205, with two Republican vacancies and one independent. As a result of this election, the 109th Congress began composed of 232 Republicans, 201 Democrats, one independent, and one vacancy. The Republicans thereby built up their House majority by 3 seats.
The 1988 United States Senate elections was an election for the United States Senate in which, in spite of the Republican victory by George H. W. Bush in the presidential election, the Democrats gained a net of one seat in the Senate. Seven seats changed parties, with four incumbents being defeated. The Democratic majority in the Senate increased by one from 54/46 to 55/45.
The 1986 United States Senate elections was an election for the United States Senate in the middle of Ronald Reagan's second presidential term. The Republicans had to defend an unusually large number of freshman Senate incumbents who had been elected on President Ronald Reagan's coattails in 1980. Democrats won a net of eight seats, defeating seven freshman incumbents and regaining control of the Senate for the first time since January 1981. The party not controlling the presidency gained seats, as usually occurs in mid-term elections.
The 1982 United States Senate elections were held on November 2, 1982. They were elections for the United States Senate following Republican gains in 1980. A total of four seats changed hands between parties, and the lone independent, Senator Harry Byrd Jr., retired. Democrats made a net gain of one seat in the elections. A special election in 1983 was then held after the winner of Washington's 1982 election died at the beginning of the term.
The 1980 United States Senate elections coincided with Ronald Reagan's victory in the presidential election. Reagan's large margin of victory over incumbent Jimmy Carter pulled in many Democratic voters and gave a huge boost to Republican Senate candidates.
The 1978 United States Senate elections in the middle of Democratic President Jimmy Carter's term. Thirteen seats changed hands between parties. The Democrats at first lost a net of two seats to the Republicans, and then one more in a special election. Democrats nevertheless retained a 58-41 majority.
The 1976 United States Senate elections was an election for the United States Senate that coincided with Democratic 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 Democrats, and the balance of the chamber remained the same.
The 1972 United States Senate elections coincided with the landslide re-election of Republican President Richard Nixon. Despite Nixon's victory, Democrats increased their majority by two seats. After the elections, Democrats held 56 seats and Republicans held 42 seats, with 1 Conservative and 1 independent Senator. These were the first elections in which all citizens at least 18 years of age could vote due to the 1971 passage of the 26th Amendment.
The 1966 United States Senate elections was an election on November 8, 1966 for the United States Senate which occurred midway through the second term of President Lyndon B. Johnson. With divisions in the Democratic base over the Vietnam War, and with the traditional mid-term advantage of the party not holding the presidency, the Republicans took three Democratic seats. Despite Republican gains, the balance remained overwhelmingly in favor of the Democrats, who retained a 64–36 majority. This was also the first election that occurred after the Voting Rights Act of 1965 became law.
The 1964 United States Senate elections 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 2019, this is the last time either party has had a two-thirds majority in the Senate, which would have hypothetically allowed the Senate Democrats to override a veto, convict and expel certain officials, or invoke cloture without any votes from Republicans. The Senate election coincided with Democratic gains in the House in the same year.
The 1962 United States Senate elections was an election for the United States Senate which was held in the middle of President John F. Kennedy's term. His Democratic Party made a net gain of three seats from the Republicans, increasing their control of the Senate.
The 1960 United States Senate elections coincided with the election of John F. Kennedy as president. The Republicans gained one seat at the expense of the Democrats. The Democrats nonetheless retained a commanding lead in the Senate with 64 seats to 36. As Majority Leader Lyndon B. 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. As is common in midterm elections, the party in the White House lost seats, but losses this year were more than usual, perhaps due to the high unemployment of the Recession of 1958. The Eisenhower Administration's position on right-to-work issues galvanized labor unions which supported Democrats. The launch of Sputnik may also have been a factor.
The 1954 United States Senate elections was a midterm election in the first term of Dwight D. Eisenhower's presidency. Eisenhower's Republican party lost a net of two seats to the Democratic opposition. This small change was just enough to give Democrats control of the chamber with the support of an Independent who caucused with them.
The 1952 United States Senate elections was an election for the United States Senate which coincided with the election of Dwight D. Eisenhower to the presidency by a large margin. The Republicans took control of the senate by managing to make a net gain of two seats, which was reduced to one when Wayne Morse (R-OR) became an independent. The Republicans still held a majority after Morse's switch. This election was the second time in history that the party in power lost their majority and the Senate Majority Leader lost his own re-election bid.
The 1950 United States Senate elections occurred in the middle of Harry S. Truman's second term as President. As with most 20th-century second-term mid-terms, the party out of the Presidency made significant gains. The Republican opposition made a net gain of five seats, taking advantage of the Democratic administration's declining popularity during the Cold War and the aftermath of the Recession of 1949. The Democrats held a narrow 49 to 47 seat majority after the election. This became the first time since 1932 that the Senate Majority Leader lost his seat and the only instance where the majority leader lost his seat while his party retained the majority.
The 1946 United States Senate elections were held November 5, 1946, in the middle of Democratic President Harry S. Truman's first term.
The United States Senate elections of 1940 coincided with the election of Franklin D. Roosevelt to his third term as President.
The United States Senate elections of 1936 coincided with the reelection of President Franklin D. Roosevelt. The Great Depression continued and voters backed progressive candidates favoring Roosevelt's New Deal in races across the country. The Democrats gained 5 net seats during the election, and in combination with Democratic and Farmer–Labor interim appointments and the defection of George W. Norris from the Republican Party to become independent, the Republicans were reduced to 16 seats, the most lopsided Senate since Reconstruction.
The United States Senate elections of 1926 were elections for the United States Senate that occurred in the middle of Republican President Calvin Coolidge's second term. The Republican majority was reduced by six seats.
