| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 625 | 1,496 | 2,163 | |
| 2020 | R | 647 | 1,518 | 2,233 | |
| 2016 | R | 563 | 1,355 | 2,089 | |
| 2012 | R | 790 | 1,225 | 2,063 | |
| 2008 | R | 914 | 1,142 | 2,110 | |
| 2004 | R | 885 | 1,470 | 2,394 | |
| 2000 | R | 794 | 1,210 | 2,112 | |
| 1996 | R | 770 | 1,009 | 2,103 | |
| 1992 | R | 822 | 885 | 2,360 | |
| 1988 | R | 1,164 | 1,182 | 2,356 | |
| 1984 | R | 821 | 1,542 | 2,396 | |
| 1980 | R | 626 | 1,719 | 2,565 | |
| 1976 | R | 1,115 | 1,298 | 2,455 | |
| 1972 | R | 917 | 1,637 | 2,554 | |
| 1968 | R | 759 | 1,508 | 2,482 | |
| 1964 | D | 1,554 | 1,312 | 2,866 | |
| 1960 | R | 1,151 | 2,098 | 3,249 | |
| 1956 | R | 1,140 | 2,160 | 3,300 | |
| 1952 | R | 978 | 2,787 | 3,765 | |
| 1948 | R | 1,291 | 1,817 | 3,108 | |
| 1944 | R | 1,019 | 2,649 | 3,668 | |
| 1940 | R | 1,357 | 2,919 | 4,276 | |
| 1936 | D | 2,359 | 2,126 | 4,525 | |
| 1932 | D | 2,505 | 1,644 | 4,181 | |
| 1928 | R | 1,485 | 2,632 | 4,134 | |
| 1924 | R | 1,285 | 2,075 | 3,834 | |
| 1920 | R | 909 | 2,416 | 3,389 | |
| 1916 | R | 1,117 | 1,373 | 2,524 | |
| 1912 | D | 890 | 672 | 2,257 | |
| 1908 | R | 1,150 | 1,357 | 2,560 | |
| 1904 | R | 642 | 1,611 | 2,539 | |
| 1900 | R | 1,179 | 1,532 | 2,793 | |
| 1896 | R | 1,246 | 1,408 | 2,728 | |
| 1892 | D | 1,150 | 234 | 2,360 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Johnson County's roughly 4,500 residents are spread across southeastern Nebraska farmland, and its presidential results have consistently ranked among the state's most lopsided, with Republican candidates routinely clearing 65% of the vote.
The Democratic margin in Johnson County peaked at thirty-nine points in 1892. By 1968 the county had flipped, voting Republican for the first time in many years. The 2024 margin was forty 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 $57,632 sits well below state and national norms, and 10% 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 Greeley County and Sherman County.