| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,006 | 6,639 | 8,795 | |
| 2020 | R | 2,153 | 6,691 | 8,994 | |
| 2016 | R | 2,113 | 6,138 | 8,613 | |
| 2012 | R | 3,191 | 4,902 | 8,290 | |
| 2008 | R | 4,284 | 4,343 | 8,782 | |
| 2004 | R | 3,341 | 4,999 | 8,394 | |
| 2000 | R | 3,833 | 4,319 | 8,262 | |
| 1996 | D | 4,076 | 3,207 | 8,642 | |
| 1992 | D | 4,211 | 3,052 | 9,168 | |
| 1988 | D | 4,320 | 4,246 | 8,597 | |
| 1984 | R | 4,006 | 4,771 | 8,813 | |
| 1980 | R | 4,335 | 4,465 | 9,103 | |
| 1976 | D | 5,198 | 3,747 | 9,006 | |
| 1972 | R | 3,624 | 5,338 | 9,001 | |
| 1968 | D | 4,453 | 4,266 | 9,874 | |
| 1964 | D | 7,351 | 3,867 | 11,260 | |
| 1960 | R | 5,975 | 6,012 | 12,060 | |
| 1956 | D | 6,048 | 5,829 | 11,946 | |
| 1952 | D | 6,964 | 5,929 | 12,988 | |
| 1948 | D | 6,705 | 4,824 | 11,801 | |
| 1944 | D | 6,420 | 5,855 | 12,397 | |
| 1940 | D | 8,667 | 6,471 | 15,289 | |
| 1936 | D | 10,203 | 4,685 | 15,154 | |
| 1932 | D | 7,835 | 3,667 | 12,477 | |
| 1928 | R | 5,642 | 6,199 | 12,134 | |
| 1924 | D | 5,213 | 5,139 | 12,053 | |
| 1920 | D | 6,160 | 5,376 | 12,991 | |
| 1916 | D | 3,880 | 2,630 | 7,463 | |
| 1912 | D | 3,707 | 1,406 | 7,771 | |
| 1908 | D | 4,657 | 2,942 | 8,248 | |
| 1904 | D | 3,641 | 3,076 | 7,295 | |
| 1900 | D | 4,008 | 2,326 | 6,591 | |
| 1896 | D | 4,010 | 2,317 | 6,409 | |
| 1892 | D | 3,159 | 1,784 | 5,462 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Sullivan County's 2024 presidential margin of R+52.7 reflects a broader realignment of southwestern Indiana's historically Democratic coal-country precincts, where union-era voting patterns have steadily given way to Republican dominance over the past two decades.
The Democratic margin in Sullivan County peaked at thirty-six points in 1936. By 2000 the county had flipped, voting Republican for the first time in many years. The 2024 margin was fifty-three points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Sullivan County's median household income of $56,204 sits well below state and national norms, and 14% 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 Clinton County and Greene County.