| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 3,479 | 7,552 | 11,094 | |
| 2020 | R | 4,037 | 7,635 | 11,815 | |
| 2016 | R | 3,874 | 7,393 | 11,419 | |
| 2012 | R | 4,723 | 7,424 | 12,249 | |
| 2008 | R | 4,817 | 7,641 | 12,610 | |
| 2004 | R | 3,272 | 7,138 | 10,474 | |
| 2000 | R | 3,227 | 6,254 | 9,574 | |
| 1996 | R | 2,851 | 4,455 | 7,877 | |
| 1992 | R | 3,213 | 5,358 | 9,326 | |
| 1988 | R | 3,016 | 6,151 | 9,223 | |
| 1984 | R | 2,894 | 5,983 | 8,924 | |
| 1980 | R | 4,015 | 5,190 | 9,334 | |
| 1976 | R | 3,600 | 4,291 | 7,960 | |
| 1972 | R | 871 | 5,669 | 6,602 | |
| 1968 | D | 1,079 | 875 | 7,018 | |
| 1964 | R | 271 | 4,949 | 5,220 | |
| 1960 | D | 1,034 | 606 | 3,208 | |
| 1956 | D | 2,140 | 467 | 3,189 | |
| 1952 | D | 2,767 | 878 | 3,645 | |
| 1948 | D | 171 | 59 | 2,572 | |
| 1944 | D | 2,470 | 78 | 2,548 | |
| 1940 | D | 2,316 | 40 | 2,357 | |
| 1936 | D | 2,445 | 48 | 2,494 | |
| 1932 | D | 1,941 | 47 | 1,989 | |
| 1928 | D | 1,893 | 231 | 2,124 | |
| 1924 | D | 1,518 | 100 | 1,625 | |
| 1920 | D | 902 | 109 | 1,025 | |
| 1916 | D | 966 | 34 | 1,006 | |
| 1912 | D | 606 | 19 | 682 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | D | 487 | 74 | 581 | |
| 1896 | D | 677 | 53 | 740 | |
| 1892 | D | 332 | 4 | 489 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Simpson County's electorate has shifted sharply toward Republican presidential candidates over the past two decades despite a Black population share near 40%, reflecting a broader realignment across rural Mississippi that has compressed Democratic performance even in historically competitive counties.
The unraveling was not abrupt. The Democratic margin in Simpson County peaked at ninety-seven points in 1940; it narrowed steadily over the late twentieth century. The 1972 election delivered the county to the Republican party for the first time in many years, by a margin of seventy-three points. By 2024, the margin had settled into deep Republican territory.
The economic and demographic context is severe. Simpson County's median household income of $56,381 is among the lowest of any county in the United States; 20% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Hancock County and Madison County.