| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,513 | 3,565 | 6,153 | |
| 2020 | R | 2,687 | 2,958 | 5,697 | |
| 2016 | R | 2,479 | 2,652 | 5,216 | |
| 2012 | D | 2,653 | 2,467 | 5,160 | |
| 2008 | D | 2,755 | 2,437 | 5,232 | |
| 2004 | D | 2,648 | 2,396 | 5,122 | |
| 2000 | D | 1,896 | 1,704 | 3,661 | |
| 1996 | D | 1,858 | 1,104 | 3,123 | |
| 1992 | D | 1,846 | 899 | 3,052 | |
| 1988 | D | 1,722 | 1,172 | 2,914 | |
| 1984 | D | 1,526 | 1,186 | 2,726 | |
| 1980 | D | 1,774 | 797 | 2,605 | |
| 1976 | D | 1,774 | 640 | 2,427 | |
| 1972 | R | 844 | 1,302 | 2,162 | |
| 1968 | D | 988 | 466 | 2,211 | |
| 1964 | R | 498 | 939 | 1,437 | |
| 1960 | D | 680 | 347 | 1,027 | |
| 1956 | D | 485 | 102 | 869 | |
| 1952 | D | 624 | 577 | 1,201 | |
| 1948 | D | 30 | 0 | 743 | |
| 1944 | D | 307 | 1 | 354 | |
| 1940 | D | 419 | 11 | 430 | |
| 1936 | D | 656 | 0 | 664 | |
| 1932 | D | 530 | 0 | 535 | |
| 1928 | D | 615 | 20 | 636 | |
| 1924 | D | 520 | 15 | 551 | |
| 1920 | D | 557 | 0 | 557 | |
| 1916 | D | 637 | 0 | 639 | |
| 1912 | — | — | — | — | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
McCormick County sits along the Georgia border wrapped around the Savannah River reservoir, with a population under 10,000 that voted Republican by 17 points in 2024 despite a substantial Black residential share that historically kept margins closer.
The Democratic margin in McCormick County has rarely exceeded 100 points in modern history; the Republican margin has rarely exceeded thirty-one points. 2024 delivered the county to the Republican candidate by seventeen points.
McCormick County's demographics resemble the country more than they resemble most counties. A 56% non-Hispanic-white share, a 18% poverty rate, and a median household income of $55,798 — all within the broad national range. The county's voting pattern over the last decade is most similar to that of Twiggs County and Jefferson County.