1978Final results
1978 election for Illinois's 17th District
U.S. House · Illinois
George M. O'Brien (R) won with 70.6% of the vote, defeating Clifford J. Sinclair (D) by 41.2 points.
George M. O'BrienRepublican · winner
70.6%94,375
Clifford J. SinclairDemocrat
29.4%39,260
133,635 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