| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,974 | 10,394 | 13,487 | |
| 2020 | R | 3,298 | 9,784 | 13,203 | |
| 2016 | R | 2,917 | 7,970 | 11,137 | |
| 2012 | R | 3,760 | 6,915 | 10,799 | |
| 2008 | R | 4,614 | 6,902 | 11,689 | |
| 2004 | R | 5,273 | 6,163 | 11,537 | |
| 2000 | D | 5,527 | 4,377 | 10,066 | |
| 1996 | D | 4,948 | 3,269 | 9,030 | |
| 1992 | D | 5,601 | 2,827 | 9,781 | |
| 1988 | D | 3,918 | 3,518 | 7,478 | |
| 1984 | R | 3,812 | 3,875 | 7,739 | |
| 1980 | D | 4,653 | 2,757 | 7,537 | |
| 1976 | D | 5,225 | 1,952 | 7,248 | |
| 1972 | R | 1,875 | 2,914 | 5,051 | |
| 1968 | D | 2,203 | 1,264 | 7,433 | |
| 1964 | D | 4,940 | 1,378 | 6,318 | |
| 1960 | D | 4,879 | 1,598 | 6,513 | |
| 1956 | D | 4,750 | 1,401 | 6,186 | |
| 1952 | D | 4,640 | 1,649 | 6,347 | |
| 1948 | D | 3,676 | 717 | 4,872 | |
| 1944 | D | 4,249 | 751 | 5,000 | |
| 1940 | D | 3,796 | 692 | 4,501 | |
| 1936 | D | 3,760 | 600 | 4,378 | |
| 1932 | D | 2,773 | 619 | 3,417 | |
| 1928 | D | 2,661 | 1,032 | 3,693 | |
| 1924 | D | 2,509 | 677 | 3,261 | |
| 1920 | D | 3,129 | 2,224 | 5,359 | |
| 1916 | D | 3,207 | 1,488 | 4,701 | |
| 1912 | D | 3,081 | 1,596 | 5,098 | |
| 1908 | D | 3,042 | 1,571 | 4,618 | |
| 1904 | D | 2,736 | 1,583 | 4,368 | |
| 1900 | D | 2,790 | 1,703 | 4,542 | |
| 1896 | D | 3,992 | 2,372 | 6,406 | |
| 1892 | D | 2,722 | 1,551 | 5,054 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Giles County sits along the Alabama border with an agricultural economy and a population under 30,000; its 2024 presidential margin of R+55 reflects a decades-long partisan realignment across small-town middle Tennessee.
The unraveling was not abrupt. The Democratic margin in Giles County peaked at seventy-two points in 1936; it narrowed steadily over the late twentieth century. The 2004 election delivered the county to the Republican party for the first time in many years, by a margin of eight points. By 2024, the margin had widened further.
The economic and demographic context is severe. Giles County's median household income of $62,307 is among the lowest of any county in the United States; 13% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Cannon County and Warren County.