1986Final results
1986 election for Michigan Senate District 31
Michigan State Senate · Michigan
Dick Posthumus (R) won with 71.5% of the vote, defeating Diane Siciliano (D) by 42.9 points.
Dick PosthumusRepublican · winner · incumbent
71.5%42,677
Diane SicilianoDemocrat
28.5%17,037
59,714 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 1986
Races before and after
Source: Harvard Dataverse / Carl KlarnerUpdated Sep 30, 2026, 7:29 AM ET