| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 83,253 | 44,982 | 129,774 | |
| 2020 | D | 73,276 | 48,187 | 122,742 | |
| 2016 | D | 50,057 | 45,724 | 99,367 | |
| 2012 | R | 43,761 | 46,774 | 91,531 | |
| 2008 | R | 40,567 | 47,157 | 88,311 | |
| 2004 | R | 21,096 | 42,759 | 64,235 | |
| 2000 | R | 11,971 | 25,815 | 38,867 | |
| 1996 | R | 9,498 | 16,968 | 29,074 | |
| 1992 | R | 7,817 | 12,634 | 24,284 | |
| 1988 | R | 4,348 | 10,882 | 15,304 | |
| 1984 | R | 4,096 | 9,142 | 13,238 | |
| 1980 | D | 5,635 | 5,326 | 11,268 | |
| 1976 | D | 5,717 | 2,622 | 8,339 | |
| 1972 | R | 1,460 | 5,155 | 6,615 | |
| 1968 | D | 2,317 | 2,017 | 7,938 | |
| 1964 | D | 3,583 | 3,125 | 6,709 | |
| 1960 | D | 2,957 | 1,041 | 3,998 | |
| 1956 | D | 2,636 | 848 | 3,484 | |
| 1952 | D | 2,589 | 553 | 3,142 | |
| 1948 | D | 1,400 | 229 | 1,846 | |
| 1944 | D | 1,461 | 152 | 1,613 | |
| 1940 | D | 1,551 | 101 | 1,654 | |
| 1936 | D | 1,362 | 116 | 1,482 | |
| 1932 | D | 1,496 | 21 | 1,532 | |
| 1928 | D | 763 | 360 | 1,123 | |
| 1924 | D | 594 | 53 | 714 | |
| 1920 | D | 608 | 0 | 608 | |
| 1916 | D | 868 | 78 | 1,035 | |
| 1912 | D | 536 | 15 | 678 | |
| 1908 | D | 369 | 194 | 641 | |
| 1904 | D | 464 | 64 | 781 | |
| 1900 | D | 639 | 378 | 1,069 | |
| 1896 | D | 569 | 568 | 1,220 | |
| 1892 | D | 718 | 578 | 1,865 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Henry County has swung dramatically toward Democrats over the past decade as Atlanta's southeastern suburbs diversified, flipping from a reliably Republican exurb to a county carried by nearly 30 points in 2024.
The county's recent history is a story of close margins. The Democratic margin reached 100 points in 1920; the Republican margin reached fifty-six points in 1972. Most other elections have been decided by single-digit points.
Henry County's demographics — a population of 249,960, a 34% non-Hispanic-white share, a median household income of $83,146 — situate the county close to national averages on several dimensions. The county's voting pattern over the last decade is most similar to that of Gwinnett County and Frederick County.
