1970Final results
1970 election for Illinois Legislative District 31
Illinois State Senate · Illinois
Robert Coulson (R) won with 52.6% of the vote, defeating Jeffrey R. Diver (D) by 5.3 points.
Robert CoulsonRepublican · winner · incumbent
52.6%25,555
Jeffrey R. DiverDemocrat
47.4%23,003
48,558 votes
Source: Harvard Dataverse / Carl KlarnerUpdated Sep 30, 2026, 7:29 AM ET
The seat over time
D − R margin in this seat's races around 1970
Races before and after
Source: Harvard Dataverse / Carl KlarnerUpdated Sep 30, 2026, 7:29 AM ET