| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 15,335 | 24,718 | 40,752 | |
| 2020 | R | 15,347 | 23,149 | 39,224 | |
| 2016 | R | 12,546 | 19,230 | 34,111 | |
| 2012 | D | 17,197 | 15,962 | 33,679 | |
| 2008 | D | 19,397 | 16,268 | 36,415 | |
| 2004 | R | 16,881 | 19,407 | 36,651 | |
| 2000 | R | 15,520 | 15,816 | 32,218 | |
| 1996 | D | 14,662 | 11,714 | 30,375 | |
| 1992 | D | 12,629 | 10,930 | 32,360 | |
| 1988 | R | 13,056 | 15,506 | 28,748 | |
| 1984 | R | 9,514 | 18,756 | 28,431 | |
| 1980 | R | 11,985 | 15,756 | 30,470 | |
| 1976 | R | 12,202 | 15,113 | 27,721 | |
| 1972 | R | 8,932 | 15,489 | 25,136 | |
| 1968 | R | 8,619 | 11,465 | 22,532 | |
| 1964 | D | 13,676 | 7,786 | 21,503 | |
| 1960 | R | 8,773 | 13,757 | 22,604 | |
| 1956 | R | 6,873 | 14,600 | 21,551 | |
| 1952 | R | 6,056 | 13,562 | 19,824 | |
| 1948 | R | 4,852 | 10,377 | 15,496 | |
| 1944 | R | 5,292 | 11,601 | 16,957 | |
| 1940 | R | 5,727 | 9,995 | 15,804 | |
| 1936 | D | 6,666 | 6,017 | 13,878 | |
| 1932 | D | 8,002 | 6,600 | 14,936 | |
| 1928 | R | 2,496 | 9,851 | 12,407 | |
| 1924 | R | 1,738 | 8,987 | 12,313 | |
| 1920 | R | 2,595 | 7,194 | 10,287 | |
| 1916 | R | 3,308 | 3,926 | 7,654 | |
| 1912 | R | 1,957 | 2,309 | 7,683 | |
| 1908 | R | 2,339 | 4,199 | 7,245 | |
| 1904 | R | 2,241 | 5,553 | 8,390 | |
| 1900 | R | 3,441 | 5,051 | 8,910 | |
| 1896 | R | 4,303 | 4,654 | 9,216 | |
| 1892 | R | 2,994 | 3,619 | 7,673 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Shiawassee County, anchored by the small city of Corunna, has shifted from a competitive bellwether to a reliably Republican county, posting a 23-point presidential margin in 2024 after voting within single digits as recently as 2008.
The Republican margin in Shiawassee County reached its widest at fifty-nine points in 1928. The margin in 2024 was twenty-three points, in line with the county's deep historical pattern.
Shiawassee County's loyalty is rooted in its place. Median household income of $67,404, a 94% non-Hispanic-white share, and a population of 67,991 together describe a community whose political habits are deeply settled. The county's voting pattern over the last decade is most similar to that of Ottawa County and Juneau County.
