United States Senate election in Florida, 1964

United States Senate elections, 1964

← 1962 November 3, 1964 1966 →
33 of the 100 seats in the United States Senate, plus 2 mid-term vacancies 51 seats needed for a majority
Majority party Minority party   Leader Mike Mansfield Everett Dirksen Party Democratic Republican Leader's seat Montana Illinois Seats before 66 34 Seats after 68 32 Seat change 2 2 Popular vote 30,217,130 22,654,661 Percentage 56.3% 42.2% Swing 5.9% 6.8% Seats up 26 9 Races won 28 7
Results including special elections      Democratic gain      Republican gain      Democratic hold      Republican hold
Majority Leader before election Mike Mansfield Democratic Elected Majority Leader Mike Mansfield Democratic

U.S. Senate election in Arizona, 1964

← 1958 1970 →
Nominee Paul Fannin Roy Elson Party Republican Democratic Popular vote 241,089 227,712 Percentage 51.43% 48.57%
Red: counties won by Fannin, Blue: counties won by Elson.
U.S. Senator before election Barry Goldwater Republican Elected U.S. Senator Paul Fannin Republican

U.S. Senate election in Connecticut, 1964

← 1958 1970 →
Nominee Thomas J. Dodd John Davis Lodge Party Democratic Republican Popular vote 781,008 426,939 Percentage 64.66% 35.34%
U.S. Senator before election Thomas J. Dodd Democratic Elected U.S. Senator Thomas J. Dodd Democratic

U.S. Senate election in Massachusetts, 1964

← 1962 1970 →
Nominee Ted Kennedy Howard J. Whitmore Jr. Party Democratic Republican Popular vote 1,716,907 587,663 Percentage 74.26% 25.42%
County Results
U.S. Senator before election Ted Kennedy Democratic Elected U.S. Senator Ted Kennedy Democratic

U.S. Senate election in Montana, 1964

← 1958 1970 →
Nominee Mike Mansfield Alex Blewett Party Democratic Republican Popular vote 180,643 99,367 Percentage 64.51% 35.49%
U.S. Senator before election Mike Mansfield Democratic Elected U.S. Senator Mike Mansfield Democratic

U.S. Senate election in Nevada, 1964

← 1958 1970 →
Nominee Howard Cannon Paul Laxalt Party Democratic Republican Popular vote 67,336 67,288 Percentage 50.02% 49.98%
U.S. Senator before election Howard Cannon Democratic Elected U.S. Senator Howard Cannon Democratic

U.S. Senate election in New Mexico, 1964

← 1958 1970 →
Nominee Joseph Montoya Edwin L. Mechem Party Democratic Republican Popular vote 178,209 147,562 Percentage 54.7% 45.3%
U.S. Senator before election Edwin L. Mechem Republican Elected U.S. Senator Joseph Montoya Democratic

U.S. Senate election in New York, 1964

← 1958 1970 →
Nominee Robert F. Kennedy Kenneth Keating Party Democratic Republican Popular vote 3,823,749 3,104,056 Percentage 53.5% 43.4%
County Results
U.S. Senator before election Kenneth Keating Republican Elected U.S. Senator Robert F. Kennedy Democratic

U.S. Senate election in Pennsylvania, 1964

← 1958 1970 →
Nominee Hugh Scott Genevieve Blatt Party Republican Democratic Popular vote 2,429,858 2,359,223 Percentage 50.6% 49.1%
County results
U.S. Senator before election Hugh Scott Republican Elected U.S. Senator Hugh Scott Republican

U.S. Senate election in Texas, 1964

← 1958 1970 →
Nominee Ralph Yarborough George H. W. Bush Party Democratic Republican Popular vote 1,463,958 1,134,337 Percentage 56.2% 43.6%
U.S. Senator before election Ralph Yarborough Democratic Elected U.S. Senator Ralph Yarborough Democratic

Mike Mansfield
Democratic

Mike Mansfield
Democratic

The United States Senate elections, 1964 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 2016, 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.

Notably, of the 34 seats up for election this year, 25 of were held by Democrats, who managed to retain 24 of them. A party defending two-thirds of the seats up for election would not make net gains in the Senate again until 2012. Coincidentally, it would be the same Senate class, class 1.

There were no net party changes from retirements.

Democrats had a two-seat net gain from beating incumbents.

In a close race in Nevada, Democratic incumbent Howard Cannon won re-election over Republican Lieutenant Governor Paul Laxalt by fewer than 100 votes. Laxalt joined Cannon in the Senate when he won Nevada's other seat in 1974.