1990Final results
1990 election for Michigan Senate District 38
Michigan State Senate · Michigan
Donald W. Koivisto (D) won with 68.1% of the vote, defeating Peter Koski (R) by 36.1 points.
Donald W. KoivistoDemocrat · winner
68.1%42,953
Peter KoskiRepublican
31.9%20,164
63,117 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 1990
Races before and after
Source: Harvard Dataverse / Carl KlarnerUpdated Sep 30, 2026, 7:29 AM ET