The 1942 United States Senate special election in Colorado took place on November 3, 1942. Democratic Senator Alva B. Adams died in office on December 1, 1941, and Republican Governor Ralph L. Carr appointed Denver oilman Eugene Millikin to fill the vacancy. Millikin ran for election for the remainder of Adams's term. He was opposed in the general election by James A. Marsh, the former chairman of the state Democratic Party. Aided in part by the nationwide Republican landslide, Millikin easily defeated Marsh to serve out the remainder of the term.
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 Results by county Millikin: 40–50% 50–60% 60–70% 70–80% Marsh: 40–50% 50–60% | |||||||||||||||||
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Democratic primary
Candidates
- James A. Marsh, former Chairman of the Colorado Democratic Party
Campaign
Most of the competitive Democratic primaries in 1942 emerged in the races for the regular Senate seat and for Governor. Former state party chairman James A. Marsh was seen as the frontrunner for the special election, along with Oscar Chapman, the U.S. Assistant Secretary of the Interior and Alva Adams's former campaign manager.[1] However, Chapman ultimately announced that he would not run, and Marsh won the nomination unopposed.[2]
Results
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Democratic | James A. Marsh | 54,606 | 100.00 | |
| Total votes | 54,606 | 100.00 | ||
Republican primary
Candidates
- Eugene Millikin, incumbent U.S. Senator
Results
| Party | Candidate | Votes | % | |
|---|---|---|---|---|
| Republican | Eugene D. Millikin (inc.) | 41,660 | 100.00 | |
| Total votes | 41,660 | 100.00 | ||
General election
Results
| Party | Candidate | Votes | % | ±% | |
|---|---|---|---|---|---|
| Republican | Eugene Millikin (inc.) | 191,517 | 56.12% | +15.94% | |
| Democratic | James A. Marsh | 143,817 | 42.14% | -16.10% | |
| Independent | Lewis Harley Tiley | 4,262 | 1.25% | — | |
| Socialist | Edgar P. Sherman | 1,664 | 0.49% | -0.31% | |
| Majority | 47,700 | 13.98% | -4.09% | ||
| Turnout | 341,260 | ||||
| Republican hold | |||||