The 1998 United States Senate elections were held on November 3 and seen as an even contest between the Republican Party and Democratic Party. While the Democrats had to defend more seats up for election, Republican attacks on the morality of President Bill Clinton failed to connect with voters and anticipated Republican gains did not materialize. The Republicans picked up open seats in Ohio and Kentucky and narrowly defeated Democratic incumbent Carol Moseley Braun (Illinois), but these were cancelled out by the Democrats' gain of an open seat in Indiana and defeats of Republican Senators Al D'Amato and Lauch Faircloth. The balance of the Senate remained unchanged at 55–45 in favor of the Republicans. With Democrats gaining five seats in the House of Representatives, this marked the first time since 1934 that the out-of-presidency party failed to gain congressional seats in a mid-term election, and the first time since 1822 that the party not in control of the White House failed to gain seats in the mid-term election of a President's second term. These are the last senate elections that resulted in no net change in the balance of power.
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 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 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 1956 United States Senate elections were elections for the United States Senate that coincided with the re-election of President Dwight D. Eisenhower. Although the Democrats gained two seats in regular elections, the Republicans gained back two seats in special elections, leaving the party balance of the chamber remained unchanged.
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 1948 United States Senate elections were elections which coincided with the election of Democratic President Harry S. Truman for a full term. Truman had campaigned against an "obstructionist" Congress that had blocked many of his initiatives, and in addition the U.S. economy recovered from the postwar recession of 1946–47 by election day. Thus Truman was rewarded with a Democratic gain of nine seats in the Senate, enough to give them control of the chamber.
The United States Senate elections of 1944 coincided with the re-election of Franklin D. Roosevelt to his fourth term as President. The Democrats' large majority remained the same, but they lost one seat to the Republicans in a special election.
The United States Senate elections of 1940 coincided with the election of Franklin D. Roosevelt to his third term as President.
Although the 17th Amendment was not passed until 1913, some states elected their Senators directly before its passage. 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 1958 New York state election was held on November 4, 1958, to elect the Governor, the Lieutenant Governor, the State Comptroller, the Attorney General, a judge of the New York Court of Appeals and a U.S. Senator, as well as all members of the New York State Assembly and the New York State Senate.
The 1974 New York state election was held on November 5, 1974, to elect the Governor, the Lieutenant Governor, the State Comptroller, the Attorney General, two judges of the New York Court of Appeals and a U.S. Senator, as well as all members of the New York State Assembly and the New York State Senate.
The 1970 New York state election was held on November 3, 1970, to elect the Governor, the Lieutenant Governor, the State Comptroller, the Attorney General and a U.S. Senator, as well as all members of the New York State Assembly and the New York State Senate.
The 1962 New York state election was held on November 6, 1962, to elect the Governor, the Lieutenant Governor, the State Comptroller, the Attorney General, a judge of the New York Court of Appeals and a U.S. Senator, as well as all members of the New York State Assembly and the New York State Senate.
The 1950 New York state election was held on November 7, 1950, to elect the Governor, the Lieutenant Governor, the State Comptroller, the Attorney General and a U.S. Senator, as well as all members of the New York State Assembly and the New York State Senate.
The 1946 New York state election was held on November 5, 1946, to elect the Governor, the Lieutenant Governor, the State Comptroller, the Attorney General, a U.S. Senator, the Chief Judge and an associate judge of the New York Court of Appeals, as well as all members of the New York State Assembly and the New York State Senate.
The 1944 New York state election was held on November 7, 1944, to elect a judge of the New York Court of Appeals and a U.S. senator, as well as all members of the New York State Assembly and the New York State Senate.
The 1964 United States Senate election in New York was held on November 3, 1964. Incumbent Republican U.S. Senator Kenneth Keating ran for re-election to a second term, but was defeated by Robert F. Kennedy.
