They coincided with Democrat Jimmy Carter's presidential election and the United States Bicentennial celebration.

As of 2025[update] this is the first and so far only time both party leaders retired from the Senate in the same election cycle since the creation of the positions.

Democratic attorney and businessman Dennis DeConcini won the open seat over Sam Steiger, U.S.

John V. Tunney Democratic S. I. Hayakawa Republican Incumbent Democrat John Tunney ran for re-election to a second term, but was defeated by Republican Sam Hayakawa, President emeritus of San Francisco State University.

Democrat Spark Matsunaga won the open seat over Republican William Quinn, Former Governor of Hawaii.

Vance Hartke Democratic Richard Lugar Republican Incumbent Democrat Vance Hartke ran for re-election to a fourth term, but was defeated by Republican challenger Richard Lugar, Mayor of Indianapolis.

J. Glenn Beall Jr. Republican Paul Sarbanes Democratic Incumbent Republican J. Glenn Beall Jr. ran for re-election to a second term, but was defeated by Democratic challenger Paul Sarbanes, member of the U.S. House of Representatives.

Democrat Donald Riegle, member of the U.S. House of Representatives, won the open seat over fellow congressman Republican Marvin Esch.

(Jerry Litton had won the Democratic nomination earlier, but was killed in a plane crash, and Hearnes was chosen by the party committee.)

United States Congressman John Melcher, who had represented Montana's 2nd congressional district from 1969 to 1977, won the Democratic nomination and defeated Stanley C. Burger, the Republican nominee and former executive officer of the Montana Farm Bureau Federation, by a wide margin in the general election.

Democrat Edward Zorinsky, Mayor of Omaha, won the open seat over Republican John Y. McCollister, U.S.

Cannon was nearly defeated for re-election in 1964 by Republican Lieutenant Governor Paul Laxalt in one of the closest election in history.

He defeated anti-abortion activist Stephen J. Foley handily in the Democratic primary with 85% of the vote.

In the general election, Williams soundly won re-election to a fourth term over Norcross.

[1] Only Burdick filed as a Dem-NPLer, and the endorsed Republican candidate was Robert Stroup, as state senator from Hazen, North Dakota.

Republican John Heinz won the open seat over Democrat Bill Green, United States Representative[16][1] In December 1975, U.S. senator Hugh Scott announced that he would not seek re-election in 1976 at the age of 75 after serving in Congress for 33 years.

[17] Heinz was the victor in all but nine counties, defeating opponent William Green, who had a 300,000 vote advantage in his native Philadelphia area.

Heinz replied to this by claiming that the spending was necessary to overcome the Democratic voter registration advantage.