| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 6,960 | 16,298 | 23,688 | |
| 2020 | R | 6,974 | 15,489 | 23,172 | |
| 2016 | R | 5,930 | 13,719 | 21,362 | |
| 2012 | R | 7,667 | 12,763 | 21,021 | |
| 2008 | R | 9,480 | 12,183 | 22,080 | |
| 2004 | R | 7,790 | 12,257 | 20,236 | |
| 2000 | R | 6,926 | 9,339 | 16,787 | |
| 1996 | R | 6,220 | 6,276 | 14,574 | |
| 1992 | D | 5,546 | 5,032 | 15,203 | |
| 1988 | R | 5,373 | 7,512 | 12,921 | |
| 1984 | R | 4,238 | 8,413 | 12,651 | |
| 1980 | R | 5,441 | 6,449 | 12,585 | |
| 1976 | D | 5,551 | 5,513 | 11,220 | |
| 1972 | R | 3,044 | 7,228 | 10,272 | |
| 1968 | R | 3,484 | 4,834 | 9,336 | |
| 1964 | D | 6,412 | 4,348 | 10,760 | |
| 1960 | R | 4,712 | 6,970 | 11,682 | |
| 1956 | R | 4,530 | 6,599 | 11,129 | |
| 1952 | R | 4,294 | 6,990 | 11,307 | |
| 1948 | R | 4,888 | 4,903 | 9,805 | |
| 1944 | R | 4,419 | 5,949 | 10,378 | |
| 1940 | R | 5,441 | 6,468 | 11,928 | |
| 1936 | D | 6,294 | 5,797 | 12,113 | |
| 1932 | D | 6,481 | 4,088 | 10,645 | |
| 1928 | R | 4,316 | 7,032 | 11,367 | |
| 1924 | D | 5,526 | 5,248 | 11,006 | |
| 1920 | R | 5,444 | 5,700 | 11,252 | |
| 1916 | D | 3,701 | 2,966 | 6,767 | |
| 1912 | D | 3,468 | 1,772 | 6,559 | |
| 1908 | D | 3,483 | 2,997 | 6,595 | |
| 1904 | D | 3,277 | 2,989 | 6,419 | |
| 1900 | D | 3,612 | 3,051 | 6,816 | |
| 1896 | D | 4,240 | 3,219 | 7,507 | |
| 1892 | D | 3,109 | 2,667 | 6,461 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Home to Warrensburg and the University of Central Missouri, Johnson County sits at the edge of the Kansas City metro but votes decidedly differently — its 2024 presidential margin of R+39.6 reflects deep rural Republican strength despite a sizable college-town presence.
The Republican margin in Johnson County reached its widest at forty-one points in 1972. The margin in 2024 was thirty-nine points, in line with the county's deep historical pattern.
Johnson County's loyalty is rooted in its place. Median household income of $67,272, a 85% non-Hispanic-white share, and a population of 54,732 together describe a community whose political habits are deeply settled. The county's voting pattern over the last decade is most similar to that of De Witt County and Crawford County.
