1978Final results
1978 election for Iowa's 3rd District
U.S. House · Iowa
Chuck Grassley (R) won with 74.8% of the vote, defeating John Knudson (D) by 49.6 points.
Chuck GrassleyRepublican · winner
74.8%103,659
John KnudsonDemocrat
25.2%34,880
138,539 votes
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 7:25 AM ET
The seat over time
D − R margin in this seat's races around 1978
Races before and after
Source: MIT Election Data and Science LabUpdated Sep 30, 2026, 7:25 AM ET