| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 3,758 | 25,633 | 29,660 | |
| 2020 | R | 4,281 | 24,767 | 29,356 | |
| 2016 | R | 3,622 | 21,405 | 25,485 | |
| 2012 | R | 5,239 | 18,331 | 23,863 | |
| 2008 | R | 5,658 | 17,957 | 24,015 | |
| 2004 | R | 7,092 | 16,904 | 24,169 | |
| 2000 | R | 7,056 | 12,827 | 20,285 | |
| 1996 | R | 6,544 | 9,823 | 18,143 | |
| 1992 | R | 8,245 | 10,519 | 21,585 | |
| 1988 | R | 7,333 | 11,478 | 18,940 | |
| 1984 | R | 7,212 | 12,098 | 19,349 | |
| 1980 | R | 8,820 | 9,673 | 18,690 | |
| 1976 | D | 9,759 | 6,597 | 16,437 | |
| 1972 | R | 3,759 | 9,434 | 13,237 | |
| 1968 | R | 1,274 | 5,314 | 14,859 | |
| 1964 | R | 0 | 6,746 | 11,694 | |
| 1960 | D | 5,844 | 5,585 | 11,441 | |
| 1956 | D | 5,768 | 5,684 | 11,468 | |
| 1952 | D | 5,209 | 3,997 | 9,217 | |
| 1948 | R | 0 | 2,743 | 6,333 | |
| 1944 | D | 4,366 | 2,627 | 7,002 | |
| 1940 | D | 5,432 | 2,810 | 8,259 | |
| 1936 | D | 6,122 | 4,617 | 10,762 | |
| 1932 | D | 4,217 | 3,496 | 7,790 | |
| 1928 | R | 3,957 | 5,761 | 9,720 | |
| 1924 | R | 3,003 | 3,434 | 6,437 | |
| 1920 | R | 3,894 | 4,852 | 8,795 | |
| 1916 | D | 1,787 | 1,190 | 3,024 | |
| 1912 | D | 1,379 | 492 | 2,525 | |
| 1908 | D | 1,395 | 1,103 | 2,556 | |
| 1904 | D | 1,716 | 1,237 | 3,069 | |
| 1900 | D | 1,873 | 1,735 | 3,707 | |
| 1896 | D | 1,586 | 1,446 | 3,106 | |
| 1892 | D | 1,868 | 5 | 3,062 | |
| 1888 | D | 1,326 | 593 | 1,936 | |
| 1884 | D | 1,077 | 465 | 1,542 | |
| 1880 | D | 759 | 252 | 1,011 | |
| 1876 | D | 987 | 447 | 1,434 |
DeKalb County's R+73.8 margin in 2024 places it among the most one-sided counties in the state, reflecting a rural, majority-white population in the Cumberland Plateau foothills where Democratic support has eroded steadily over two decades.
The Democratic margin in DeKalb County peaked at sixty-one points in 1892. By 1980 the county had flipped, voting Republican for the first time in many years. The 2024 margin was seventy-four points, the most Republican-leaning result in the county's modern history.
The economic context is the key. DeKalb County's median household income of $51,204 sits well below state and national norms, and 22% 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 Chester County and Marshall County.