| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 5,957 | 17,080 | 23,362 | |
| 2020 | R | 5,966 | 16,194 | 22,446 | |
| 2016 | R | 4,873 | 13,446 | 19,249 | |
| 2012 | R | 7,212 | 10,963 | 18,450 | |
| 2008 | R | 9,047 | 10,679 | 20,169 | |
| 2004 | R | 7,883 | 12,632 | 20,763 | |
| 2000 | R | 7,153 | 10,966 | 18,566 | |
| 1996 | R | 7,092 | 7,821 | 17,314 | |
| 1992 | R | 5,868 | 7,891 | 18,758 | |
| 1988 | R | 5,445 | 10,653 | 16,207 | |
| 1984 | R | 4,126 | 12,627 | 16,810 | |
| 1980 | R | 4,898 | 12,158 | 18,117 | |
| 1976 | R | 6,042 | 10,597 | 16,856 | |
| 1972 | R | 3,780 | 11,031 | 15,125 | |
| 1968 | R | 3,193 | 9,273 | 14,168 | |
| 1964 | R | 6,266 | 7,590 | 13,874 | |
| 1960 | R | 4,153 | 11,005 | 15,185 | |
| 1956 | R | 2,954 | 11,095 | 14,066 | |
| 1952 | R | 2,298 | 11,181 | 13,557 | |
| 1948 | R | 2,167 | 8,237 | 10,606 | |
| 1944 | R | 2,015 | 9,512 | 11,587 | |
| 1940 | R | 2,195 | 10,289 | 12,527 | |
| 1936 | R | 3,285 | 6,975 | 11,036 | |
| 1932 | R | 4,077 | 6,860 | 11,205 | |
| 1928 | R | 1,736 | 7,888 | 9,668 | |
| 1924 | R | 983 | 7,767 | 9,188 | |
| 1920 | R | 1,146 | 7,256 | 8,571 | |
| 1916 | R | 1,867 | 4,639 | 6,663 | |
| 1912 | R | 1,161 | 2,166 | 6,728 | |
| 1908 | R | 1,474 | 4,173 | 6,051 | |
| 1904 | R | 1,217 | 4,671 | 6,281 | |
| 1900 | R | 2,065 | 4,173 | 6,527 | |
| 1896 | R | 3,156 | 3,634 | 7,024 | |
| 1892 | R | 1,730 | 2,494 | 4,590 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
This rural county at the tip of Michigan's Thumb peninsula recorded an R+47.7 margin in 2024, among the largest in the state, driven by a predominantly white, non-college population spread across small farming communities and shoreline townships.
The Republican margin in Sanilac County reached its widest at seventy-four points in 1924. The margin in 2024 was forty-eight points, in line with the county's deep historical pattern.
Sanilac County's loyalty is rooted in its place. Median household income of $58,863, a 93% non-Hispanic-white share, and a population of 40,462 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 Newaygo County and Susquehanna County.