| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 8,021 | 22,978 | 31,225 | |
| 2020 | R | 9,080 | 22,609 | 32,047 | |
| 2016 | R | 9,132 | 20,550 | 31,513 | |
| 2012 | R | 15,077 | 15,492 | 31,971 | |
| 2008 | R | 14,926 | 16,994 | 32,723 | |
| 2004 | R | 16,827 | 18,259 | 35,203 | |
| 2000 | R | 13,997 | 15,022 | 29,945 | |
| 1996 | D | 15,041 | 11,679 | 31,328 | |
| 1992 | D | 14,715 | 11,931 | 33,624 | |
| 1988 | R | 14,442 | 16,029 | 30,760 | |
| 1984 | R | 14,120 | 18,818 | 33,219 | |
| 1980 | R | 15,552 | 15,881 | 32,568 | |
| 1976 | D | 18,019 | 13,021 | 31,488 | |
| 1972 | R | 11,008 | 19,998 | 31,679 | |
| 1968 | R | 13,836 | 15,310 | 32,317 | |
| 1964 | D | 21,559 | 13,465 | 35,024 | |
| 1960 | R | 16,647 | 21,771 | 38,418 | |
| 1956 | R | 14,985 | 22,110 | 37,095 | |
| 1952 | R | 18,145 | 20,403 | 38,548 | |
| 1948 | D | 17,923 | 16,800 | 34,852 | |
| 1944 | R | 17,134 | 17,489 | 34,623 | |
| 1940 | D | 21,926 | 19,462 | 41,388 | |
| 1936 | D | 22,243 | 17,860 | 40,380 | |
| 1932 | R | 15,817 | 17,225 | 33,590 | |
| 1928 | R | 7,425 | 20,997 | 28,530 | |
| 1924 | R | 5,532 | 12,189 | 19,401 | |
| 1920 | R | 7,682 | 11,871 | 20,135 | |
| 1916 | R | 4,808 | 6,356 | 11,809 | |
| 1912 | R | 3,508 | 3,609 | 10,547 | |
| 1908 | R | 4,310 | 5,790 | 10,818 | |
| 1904 | R | 2,420 | 5,540 | 8,855 | |
| 1900 | R | 3,629 | 5,756 | 9,570 | |
| 1896 | R | 3,658 | 5,492 | 9,240 | |
| 1892 | R | 3,181 | 4,268 | 7,639 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Scioto County, anchored by Portsmouth along the Ohio River, has swung decisively in successive presidential cycles, posting a 48-point Republican margin in 2024 — a pattern common to deindustrialized Appalachian Ohio counties where college-degree attainment trails state averages.
The Democratic margin in Scioto County peaked at twenty-three points in 1964. By 2000 the county had flipped, voting Republican for the first time in many years. The 2024 margin was forty-eight points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Scioto County's median household income of $50,609 sits well below state and national norms, and 22% 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 Pike County and Vinton County.