1966 United States Senate election in South Dakota

1966 United States Senate election in South Dakota

November 8, 1966
 
Nominee Karl Mundt Donn H. Wright
Party Republican Democratic
Popular vote 150,517 76,563
Percentage 66.28% 33.72%

County results
Mundt:      50–60%      60–70%      70–80%      80–90%
Wright:      50–60%

U.S. senator before election

Karl E. Mundt
Republican

Elected U.S. Senator

Karl E. Mundt
Republican

The 1966 United States Senate election in South Dakota took place on November 8, 1966. Incumbent Republican Senator Karl E. Mundt ran for re-election to his fourth term. He was challenged in the Republican primary by a John Birch Society member, but easily turned away the challenge. In the general election, he faced State Representative Donn Wright, the Democratic nominee. Owing in large part to the Republican landslide taking place nationwide, Mundt defeated Wright by an unprecedented margin.

South Dakota would not elect another Senator to a fourth term until John Thune in 2022, it was dubbed the "Mundt curse".