| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,265 | 6,639 | 9,018 | |
| 2020 | R | 2,400 | 6,334 | 8,859 | |
| 2016 | R | 2,031 | 5,435 | 7,781 | |
| 2012 | R | 2,471 | 4,556 | 7,163 | |
| 2008 | R | 2,916 | 4,520 | 7,590 | |
| 2004 | R | 2,807 | 4,855 | 7,731 | |
| 2000 | R | 2,658 | 3,793 | 6,611 | |
| 1996 | D | 2,934 | 2,433 | 6,204 | |
| 1992 | D | 2,795 | 2,148 | 6,189 | |
| 1988 | R | 2,748 | 2,983 | 5,753 | |
| 1984 | R | 2,405 | 3,467 | 5,890 | |
| 1980 | D | 3,319 | 2,184 | 5,645 | |
| 1976 | D | 3,582 | 1,911 | 5,551 | |
| 1972 | R | 1,780 | 2,732 | 4,576 | |
| 1968 | D | 2,373 | 1,637 | 4,850 | |
| 1964 | D | 4,179 | 1,054 | 5,246 | |
| 1960 | D | 3,481 | 2,306 | 5,787 | |
| 1956 | D | 3,515 | 2,128 | 5,657 | |
| 1952 | D | 3,367 | 1,866 | 5,240 | |
| 1948 | D | 3,494 | 1,224 | 4,802 | |
| 1944 | D | 3,706 | 1,466 | 5,192 | |
| 1940 | D | 4,228 | 1,707 | 5,954 | |
| 1936 | D | 4,378 | 1,756 | 6,149 | |
| 1932 | D | 4,909 | 1,833 | 6,790 | |
| 1928 | D | 3,164 | 2,909 | 6,078 | |
| 1924 | D | 3,924 | 2,165 | 6,189 | |
| 1920 | D | 4,804 | 2,378 | 7,239 | |
| 1916 | D | 2,778 | 1,409 | 4,246 | |
| 1912 | D | 2,514 | 1,193 | 3,974 | |
| 1908 | D | 2,797 | 1,571 | 4,430 | |
| 1904 | D | 2,688 | 1,538 | 4,299 | |
| 1900 | D | 2,801 | 1,843 | 4,675 | |
| 1896 | D | 2,690 | 1,705 | 4,527 | |
| 1892 | D | 2,172 | 1,273 | 3,664 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Harrison County's R+48.5 margin in 2024 places it among Kentucky's most decisive rural counties. Its roughly 18,000 residents are concentrated in Cynthiana, a small Bluegrass-region seat with a manufacturing and agricultural employment base.
The unraveling was not abrupt. The Democratic margin in Harrison County peaked at sixty points in 1964; it narrowed steadily over the late twentieth century. The 2000 election delivered the county to the Republican party for the first time in many years, by a margin of seventeen points. By 2024, the margin had widened further.
The economic and demographic context is severe. Harrison County's median household income of $66,442 is among the lowest of any county in the United States; 17% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Caldwell County and Sweetwater County.