| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 299,630 | 62,622 | 368,182 | |
| 2020 | D | 308,227 | 58,373 | 370,804 | |
| 2016 | D | 251,370 | 51,468 | 317,849 | |
| 2012 | D | 238,224 | 64,392 | 306,858 | |
| 2008 | D | 254,594 | 65,581 | 322,301 | |
| 2004 | D | 200,787 | 73,570 | 276,771 | |
| 2000 | D | 154,509 | 58,807 | 219,980 | |
| 1996 | D | 137,903 | 60,255 | 207,229 | |
| 1992 | D | 124,559 | 70,282 | 215,435 | |
| 1988 | D | 92,521 | 90,179 | 184,250 | |
| 1984 | R | 77,329 | 104,697 | 182,026 | |
| 1980 | D | 82,743 | 74,904 | 167,405 | |
| 1976 | D | 86,872 | 67,160 | 154,032 | |
| 1972 | R | 30,671 | 104,750 | 135,421 | |
| 1968 | R | 27,796 | 52,485 | 104,237 | |
| 1964 | R | 37,154 | 49,448 | 86,602 | |
| 1960 | D | 24,116 | 24,046 | 48,162 | |
| 1956 | D | 29,915 | 15,718 | 45,633 | |
| 1952 | D | 20,865 | 15,588 | 36,453 | |
| 1948 | D | 10,826 | 5,758 | 19,521 | |
| 1944 | D | 12,069 | 2,555 | 14,625 | |
| 1940 | D | 8,862 | 2,081 | 10,988 | |
| 1936 | D | 7,391 | 1,137 | 8,560 | |
| 1932 | D | 5,323 | 633 | 6,039 | |
| 1928 | R | 2,293 | 2,378 | 4,671 | |
| 1924 | D | 2,277 | 590 | 3,241 | |
| 1920 | D | 1,847 | 803 | 2,650 | |
| 1916 | D | 1,690 | 12 | 1,899 | |
| 1912 | D | 837 | 44 | 991 | |
| 1908 | D | 740 | 356 | 1,361 | |
| 1904 | D | 759 | 213 | 1,325 | |
| 1900 | D | 756 | 216 | 1,045 | |
| 1896 | D | 815 | 439 | 1,353 | |
| 1892 | D | 1,370 | 496 | 2,398 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
DeKalb anchors Atlanta's eastern suburbs with a majority-Black population and a college-educated professional base, producing presidential margins above 60 points Democratic in every cycle since 2008.
The unraveling was not abrupt. The Democratic margin in DeKalb County peaked at eighty-eight points in 1916; it narrowed steadily over the late twentieth century. The 1988 election delivered the county to the Republican party for the first time in many years, by a margin of one points. By 2024, the margin had widened further.
The economic and demographic context is severe. DeKalb County's median household income of $80,644 is among the lowest of any county in the United States; 14% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Mercer County and Washtenaw County.
