| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 437 | 2,072 | 2,565 | |
| 2020 | R | 461 | 2,168 | 2,678 | |
| 2016 | R | 393 | 1,996 | 2,587 | |
| 2012 | R | 550 | 1,759 | 2,389 | |
| 2008 | R | 736 | 1,999 | 2,796 | |
| 2004 | R | 727 | 2,154 | 2,930 | |
| 2000 | R | 869 | 2,076 | 3,055 | |
| 1996 | R | 836 | 1,941 | 3,159 | |
| 1992 | R | 845 | 1,371 | 3,378 | |
| 1988 | R | 1,235 | 1,941 | 3,268 | |
| 1984 | R | 893 | 2,521 | 3,449 | |
| 1980 | R | 990 | 2,254 | 3,512 | |
| 1976 | R | 1,681 | 1,777 | 3,554 | |
| 1972 | R | 729 | 2,628 | 3,471 | |
| 1968 | R | 1,015 | 2,351 | 3,674 | |
| 1964 | R | 1,813 | 1,969 | 3,810 | |
| 1960 | R | 1,439 | 3,158 | 4,622 | |
| 1956 | R | 1,311 | 3,111 | 4,445 | |
| 1952 | R | 927 | 3,575 | 4,547 | |
| 1948 | R | 1,752 | 2,702 | 4,560 | |
| 1944 | R | 1,573 | 2,849 | 4,468 | |
| 1940 | R | 2,478 | 3,205 | 5,751 | |
| 1936 | D | 3,391 | 2,441 | 5,854 | |
| 1932 | D | 2,860 | 2,116 | 5,145 | |
| 1928 | R | 1,005 | 3,712 | 4,768 | |
| 1924 | R | 1,321 | 2,280 | 4,282 | |
| 1920 | R | 1,486 | 2,593 | 4,206 | |
| 1916 | D | 2,648 | 1,797 | 4,884 | |
| 1912 | D | 1,274 | 365 | 3,138 | |
| 1908 | R | 1,404 | 1,490 | 3,075 | |
| 1904 | R | 597 | 1,459 | 2,364 | |
| 1900 | D | 1,261 | 1,190 | 2,530 | |
| 1896 | D | 1,332 | 812 | 2,173 | |
| 1892 | R | 0 | 1,986 | 3,339 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Harper County's R+64 margin in 2024 places it among the most uniformly Republican counties in Kansas, a pattern consistent with its sparse, agriculturally dependent population on the Oklahoma border.
The Republican margin in Harper County reached its widest at sixty-four points in 2024. The margin in 2024 was sixty-four points, in line with the county's deep historical pattern.
Harper County's loyalty is rooted in its place. Median household income of $53,488, a 89% non-Hispanic-white share, and a population of 5,400 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 Decatur County and Wabaunsee County.
