| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,107 | 6,766 | 9,059 | |
| 2020 | R | 2,283 | 6,938 | 9,498 | |
| 2016 | R | 2,427 | 6,091 | 8,812 | |
| 2012 | R | 2,799 | 5,064 | 8,098 | |
| 2008 | R | 3,034 | 4,922 | 8,180 | |
| 2004 | R | 3,622 | 4,311 | 8,044 | |
| 2000 | R | 3,270 | 3,657 | 7,161 | |
| 1996 | D | 3,585 | 2,367 | 6,833 | |
| 1992 | D | 3,951 | 2,563 | 7,578 | |
| 1988 | R | 2,818 | 4,046 | 6,941 | |
| 1984 | R | 3,056 | 4,720 | 7,827 | |
| 1980 | D | 3,709 | 3,619 | 7,636 | |
| 1976 | D | 5,044 | 2,173 | 7,217 | |
| 1972 | R | 2,045 | 4,107 | 6,152 | |
| 1968 | D | 1,747 | 1,667 | 5,107 | |
| 1964 | D | 3,127 | 1,535 | 4,683 | |
| 1960 | D | 1,938 | 1,490 | 3,523 | |
| 1956 | D | 1,697 | 1,520 | 3,245 | |
| 1952 | D | 2,021 | 1,728 | 3,765 | |
| 1948 | D | 1,565 | 523 | 2,249 | |
| 1944 | D | 1,311 | 593 | 1,911 | |
| 1940 | D | 1,429 | 318 | 1,756 | |
| 1936 | D | 1,432 | 318 | 1,772 | |
| 1932 | D | 1,557 | 284 | 1,908 | |
| 1928 | D | 1,292 | 766 | 2,074 | |
| 1924 | D | 1,029 | 311 | 1,572 | |
| 1920 | D | 1,579 | 996 | 2,755 | |
| 1916 | D | 1,479 | 571 | 2,050 | |
| 1912 | D | 927 | 189 | 1,504 | |
| 1908 | D | 1,164 | 544 | 1,867 | |
| 1904 | D | 1,047 | 507 | 1,620 | |
| 1900 | D | 1,317 | 552 | 1,884 | |
| 1896 | D | 1,831 | 491 | 2,331 | |
| 1892 | D | 1,479 | 514 | 2,246 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Johnson County delivered a 51-point presidential margin in 2024, consistent with the broader shift toward lopsided GOP margins across rural Arkansas hill country over the past two decades.
The unraveling was not abrupt. The Democratic margin in Johnson County peaked at sixty-seven points in 1932; 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 five points. By 2024, the margin had widened further.
The economic and demographic context is severe. Johnson County's median household income of $45,995 is among the lowest of any county in the United States; 20% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Yell County and Van Buren County.
