| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 1,350 | 8,150 | 9,637 | |
| 2020 | R | 1,608 | 8,450 | 10,192 | |
| 2016 | R | 1,250 | 8,043 | 9,572 | |
| 2012 | R | 1,723 | 7,095 | 9,035 | |
| 2008 | R | 2,407 | 5,948 | 8,517 | |
| 2004 | R | 3,288 | 5,940 | 9,304 | |
| 2000 | R | 3,251 | 4,783 | 8,180 | |
| 1996 | D | 3,348 | 3,262 | 7,664 | |
| 1992 | D | 3,669 | 3,614 | 8,436 | |
| 1988 | R | 3,538 | 4,619 | 8,211 | |
| 1984 | R | 3,078 | 5,225 | 8,349 | |
| 1980 | R | 3,142 | 5,039 | 8,329 | |
| 1976 | R | 3,683 | 4,891 | 8,635 | |
| 1972 | R | 1,840 | 4,907 | 6,792 | |
| 1968 | R | 2,142 | 4,046 | 6,536 | |
| 1964 | R | 3,053 | 3,075 | 6,157 | |
| 1960 | R | 2,622 | 5,317 | 7,939 | |
| 1956 | R | 2,356 | 5,802 | 8,165 | |
| 1952 | R | 2,654 | 5,199 | 7,856 | |
| 1948 | R | 2,378 | 3,993 | 6,392 | |
| 1944 | R | 2,222 | 4,642 | 6,874 | |
| 1940 | R | 3,042 | 5,042 | 8,094 | |
| 1936 | R | 3,106 | 4,305 | 7,430 | |
| 1932 | R | 3,134 | 4,871 | 8,026 | |
| 1928 | R | 1,869 | 5,339 | 7,217 | |
| 1924 | R | 1,480 | 3,078 | 4,991 | |
| 1920 | R | 1,714 | 4,373 | 6,137 | |
| 1916 | R | 1,253 | 2,500 | 3,816 | |
| 1912 | D | 1,034 | 998 | 3,394 | |
| 1908 | R | 1,004 | 2,336 | 3,401 | |
| 1904 | R | 886 | 1,925 | 2,837 | |
| 1900 | R | 1,025 | 1,897 | 2,945 | |
| 1896 | R | 975 | 1,794 | 2,800 | |
| 1892 | R | 785 | 1,340 | 2,222 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
A rural Appalachian county in eastern Kentucky, Johnson delivered an R+70.7 margin in 2024, placing it among the most one-sided presidential results in the state and reflecting a broader realignment across the region's working-class electorate.
The Democratic margin in Johnson County peaked at one points in 1996. By 2000 the county had flipped, voting Republican for the first time in many years. The 2024 margin was seventy-one points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Johnson County's median household income of $44,904 sits well below state and national norms, and 23% 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 Alcorn County and Martin County.