| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 1,313 | 2,479 | 3,844 | |
| 2020 | R | 1,391 | 2,358 | 3,804 | |
| 2016 | R | 1,176 | 2,066 | 3,433 | |
| 2012 | R | 1,586 | 1,906 | 3,539 | |
| 2008 | D | 1,966 | 1,823 | 3,885 | |
| 2004 | R | 1,863 | 2,262 | 4,192 | |
| 2000 | R | 1,514 | 2,472 | 4,151 | |
| 1996 | D | 2,080 | 1,523 | 4,247 | |
| 1992 | D | 2,451 | 1,463 | 4,745 | |
| 1988 | D | 2,517 | 2,023 | 4,562 | |
| 1984 | R | 2,350 | 2,464 | 4,836 | |
| 1980 | R | 2,375 | 2,569 | 5,248 | |
| 1976 | D | 3,104 | 2,462 | 5,607 | |
| 1972 | R | 2,140 | 3,040 | 5,286 | |
| 1968 | D | 2,462 | 2,290 | 5,009 | |
| 1964 | D | 3,485 | 1,658 | 5,150 | |
| 1960 | R | 2,553 | 2,620 | 5,175 | |
| 1956 | R | 2,175 | 2,976 | 5,155 | |
| 1952 | R | 2,134 | 2,961 | 5,159 | |
| 1948 | R | 2,163 | 2,561 | 5,104 | |
| 1944 | D | 2,611 | 2,433 | 5,061 | |
| 1940 | D | 3,103 | 2,880 | 6,116 | |
| 1936 | D | 3,233 | 2,162 | 5,563 | |
| 1932 | D | 2,337 | 2,287 | 5,023 | |
| 1928 | R | 1,353 | 2,394 | 4,013 | |
| 1924 | R | 417 | 2,249 | 3,149 | |
| 1920 | R | 657 | 1,977 | 2,920 | |
| 1916 | R | 888 | 1,235 | 2,275 | |
| 1912 | R | 359 | 719 | 1,748 | |
| 1908 | R | 425 | 1,249 | 1,750 | |
| 1904 | R | 355 | 1,345 | 1,745 | |
| 1900 | R | 429 | 982 | 1,427 | |
| 1896 | R | 416 | 757 | 1,206 | |
| 1892 | D | 1,041 | 678 | 1,753 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Ontonagon's population has fallen by more than half since 1960, and its heavily rural, resource-economy roots correlate with some of the widest Republican presidential margins in Michigan, reaching R+30 in 2024.
The Republican margin in Ontonagon County reached its widest at fifty-eight points in 1924. The margin in 2024 was thirty points, in line with the county's deep historical pattern.
Ontonagon County's loyalty is rooted in its place. Median household income of $54,398, a 93% non-Hispanic-white share, and a population of 5,850 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 Baraga County and Red Lake County.
