The 1980 United States Senate election in Iowa was held on November 4, 1980. Incumbent Democratic United States Senator John Culver ran for reelection to a second term, but lost to Republican nominee Chuck Grassley, the United States Congressman from Iowa's 3rd congressional district. This election marked the beginning of eight consecutive victories for Grassley in the Senate. It remains the closest election of his Senate career.[citation needed]
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County results | |||||||||||||||||
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| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Democratic | John Culver (incumbent) | 95,656 | 99.95% | |
| Democratic | Write-ins | 52 | 0.05% | |
| Total votes | 95,708 | 100.00% | ||
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Republican | Chuck Grassley | 170,120 | 65.54% | |
| Republican | Tom Stoner | 89,409 | 34.45% | |
| Republican | Write-ins | 34 | 0.01% | |
| Total votes | 259,563 | 100.00% | ||
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Republican | Chuck Grassley | 683,014 | 53.49% | +4.21% | |
| Democratic | John Culver (incumbent) | 581,545 | 45.54% | −4.48% | |
| Independent | Garry De Young | 5,858 | 0.46% | ||
| Libertarian | Robert V. Hengerer | 4,233 | 0.33% | ||
| Independent | John Ingram Henderson | 2,336 | 0.18% | ||
| Majority | 101,469 | 7.95% | +7.20% | ||
| Turnout | 1,772,983 | ||||
| Republican gain from Democratic | Swing | ||||
