Former California governor and actor Ronald Reagan won the Wisconsin Republican primary in 1980. He would go on to win the Republican nomination and defeat incumbent Democratic President Jimmy Carter in a landslide in the general election.

Wisconsin Republican primary election resultsDate: April 1, 1980Winner: Ronald ReaganVotes for: 364,898 (40%)Runner up: George H. W. Bush (30%)Wisconsin general election resultsDate: Nov. 4, 1980Winner: Ronald ReaganVotes for: 1,088,845 (48%)National winner: Ronald Reagan