The 1974 United States Senate election in Colorado took place on November 5, 1974. Incumbent Republican U.S. Senator Peter Dominick ran for re-election to a third term in office, but was defeated by Democrat Gary Hart. As of 2024, this is the last time that an incumbent Senator from Colorado lost re-election for this seat, and the last time that El Paso County voted for the Democratic candidate in a Senate election.
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 County results Hart: 40–50% 50–60% 60–70% | |||||||||||||||||
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Democratic primary edit
Candidates edit
- Gary Hart, campaign manager for George McGovern in 1972
- Marty Miller, Arapahoe County District Attorney
- Herrick Roth, former State Senator from Denver
Results edit
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Democratic | Gary Hart | 81,161 | 39.92% | |
| Democratic | Herrick Roth | 66,819 | 32.86% | |
| Democratic | Marty Miller | 55,339 | 27.22% | |
| Total votes | 203,319 | 100.00% | ||
General election edit
Results edit
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Democratic | Gary Hart | 471,691 | 57.23% |  15.78
| |
| Republican | Peter Dominick (incumbent) | 325,508 | 39.50% |  19.05
| |
| Independent | John M. King | 16,131 | 1.96% | N/A | |
| Prohibition | Joseph Fred Hyskell | 8,410 | 1.02% | 1.02
| |
| Independent | Henry John Olshaw | 2,395 | 0.29% | N/A | |
| Independent | Jack Marsh (write-in) | 31 | 0.00% | N/A | |
| Total votes | 824,166 | 100.00% | |||
| Democratic gain from Republican | Swing | ||||