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 County results Wallgren: 50–60% 60–70% Chadwick: 50–60% 60–70% 70–80% | |||||||||||||||||
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| Elections in Washington |
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The 1940 United States Senate election in Washington was held on November 5, 1940. Incumbent Democrat Lewis Schwellenbach did not run for a second term in office. He was succeeded by Democratic U.S. Representative Monrad C. Wallgren, who defeated Republican Stephen Foster Chadwick for the open seat.