| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,111 | 8,232 | 10,547 | |
| 2020 | R | 2,526 | 8,491 | 11,206 | |
| 2016 | R | 2,081 | 7,654 | 10,269 | |
| 2012 | R | 3,778 | 5,741 | 9,790 | |
| 2008 | R | 4,484 | 5,853 | 10,603 | |
| 2004 | R | 5,408 | 6,487 | 11,990 | |
| 2000 | R | 4,963 | 5,972 | 11,223 | |
| 1996 | D | 5,284 | 3,581 | 10,433 | |
| 1992 | D | 5,331 | 3,808 | 11,200 | |
| 1988 | D | 5,468 | 5,332 | 10,825 | |
| 1984 | R | 5,701 | 6,648 | 12,393 | |
| 1980 | R | 5,683 | 6,040 | 12,108 | |
| 1976 | D | 6,769 | 5,205 | 11,974 | |
| 1972 | R | 4,008 | 7,129 | 11,137 | |
| 1968 | R | 4,549 | 5,208 | 10,636 | |
| 1964 | D | 6,511 | 4,467 | 10,978 | |
| 1960 | R | 4,522 | 6,424 | 10,946 | |
| 1956 | R | 3,769 | 6,306 | 10,075 | |
| 1952 | R | 3,824 | 6,102 | 9,926 | |
| 1948 | R | 4,038 | 5,453 | 9,491 | |
| 1944 | R | 3,662 | 5,609 | 9,271 | |
| 1940 | R | 4,521 | 6,239 | 10,760 | |
| 1936 | R | 4,852 | 5,894 | 10,782 | |
| 1932 | D | 5,027 | 4,655 | 9,758 | |
| 1928 | R | 2,814 | 5,125 | 7,992 | |
| 1924 | R | 3,308 | 4,225 | 8,090 | |
| 1920 | R | 3,177 | 4,912 | 8,203 | |
| 1916 | R | 2,336 | 2,454 | 4,891 | |
| 1912 | D | 1,812 | 1,024 | 4,775 | |
| 1908 | R | 1,928 | 3,116 | 5,125 | |
| 1904 | R | 2,125 | 2,983 | 5,163 | |
| 1900 | D | 3,162 | 2,461 | 5,643 | |
| 1896 | R | 2,492 | 3,066 | 5,579 | |
| 1892 | R | 2,260 | 2,600 | 4,965 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Mason County, hugging the Ohio River in the state's western panhandle, recorded an R+58 presidential margin in 2024—a result consistent with the steep partisan realignment that has reshaped rural Appalachian counties over the past two decades.
The Democratic margin in Mason County peaked at nineteen points in 1964. By 2000 the county had flipped, voting Republican for the first time in many years. The 2024 margin was fifty-eight points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Mason County's median household income of $49,761 sits well below state and national norms, and 19% of residents live below the federal poverty line. The shift here is part of a broader realignment of working-class places across the country. The county's voting pattern over the last decade is most similar to that of Calhoun County and Chariton County.