| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 3,725 | 1,542 | 5,307 | |
| 2020 | D | 4,648 | 1,598 | 6,291 | |
| 2016 | D | 4,746 | 1,581 | 6,384 | |
| 2012 | D | 5,421 | 1,586 | 7,027 | |
| 2008 | D | 5,264 | 1,731 | 7,020 | |
| 2004 | D | 4,527 | 1,880 | 6,433 | |
| 2000 | D | 4,415 | 1,629 | 6,088 | |
| 1996 | D | 4,706 | 1,561 | 6,456 | |
| 1992 | D | 4,810 | 1,807 | 7,025 | |
| 1988 | D | 4,390 | 2,212 | 6,630 | |
| 1984 | D | 4,478 | 2,493 | 6,993 | |
| 1980 | D | 5,015 | 2,104 | 7,199 | |
| 1976 | D | 3,457 | 2,191 | 5,689 | |
| 1972 | D | 2,737 | 2,686 | 5,461 | |
| 1968 | D | 2,336 | 303 | 4,807 | |
| 1964 | R | 0 | 1,653 | 2,058 | |
| 1960 | D | 765 | 623 | 1,462 | |
| 1956 | D | 981 | 578 | 1,671 | |
| 1952 | D | 894 | 702 | 1,599 | |
| 1948 | R | 0 | 52 | 1,113 | |
| 1944 | D | 1,075 | 53 | 1,131 | |
| 1940 | D | 1,404 | 46 | 1,451 | |
| 1936 | D | 1,369 | 24 | 1,393 | |
| 1932 | D | 1,293 | 26 | 1,319 | |
| 1928 | D | 1,015 | 191 | 1,206 | |
| 1924 | D | 837 | 28 | 884 | |
| 1920 | D | 1,088 | 15 | 1,106 | |
| 1916 | D | 770 | 8 | 784 | |
| 1912 | D | 701 | 9 | 722 | |
| 1908 | D | 719 | 3 | 728 | |
| 1904 | D | 883 | 16 | 906 | |
| 1900 | D | 1,053 | 204 | 1,281 | |
| 1896 | D | 1,834 | 1,459 | 3,497 | |
| 1892 | D | 3,185 | 781 | 4,026 | |
| 1888 | D | 2,060 | 819 | 2,890 | |
| 1884 | D | 1,525 | 963 | 2,494 | |
| 1880 | D | 1,787 | 1,337 | 3,124 | |
| 1876 | D | 2,234 | 1,370 | 3,604 |
Sumter County's electorate is majority Black, a legacy of the Black Belt's plantation-era demographics, and it has returned Democratic presidential margins exceeding 40 points in recent cycles.
The unraveling was not abrupt. The Democratic margin in Sumter County peaked at ninety-eight points in 1908; it narrowed steadily over the late twentieth century. The 1968 election delivered the county to the Republican party for the first time in many years, by a margin of forty-two points. By 2024, the margin had widened further.
The economic and demographic context is severe. Sumter County's median household income of $33,310 is among the lowest of any county in the United States; 27% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Greene County and Lowndes County.
