| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,527 | 7,810 | 10,581 | |
| 2020 | R | 2,591 | 8,105 | 10,928 | |
| 2016 | R | 2,076 | 6,984 | 9,722 | |
| 2012 | R | 2,658 | 6,260 | 9,141 | |
| 2008 | R | 3,353 | 6,737 | 10,337 | |
| 2004 | R | 3,217 | 7,092 | 10,488 | |
| 2000 | R | 3,549 | 6,176 | 10,232 | |
| 1996 | R | 3,638 | 5,952 | 10,977 | |
| 1992 | R | 3,564 | 4,087 | 11,588 | |
| 1988 | R | 4,417 | 5,394 | 10,042 | |
| 1984 | R | 3,708 | 6,942 | 10,793 | |
| 1980 | R | 3,761 | 6,038 | 10,496 | |
| 1976 | D | 5,385 | 4,645 | 10,340 | |
| 1972 | R | 2,685 | 6,941 | 10,195 | |
| 1968 | R | 3,562 | 5,622 | 10,320 | |
| 1964 | D | 5,574 | 4,760 | 10,450 | |
| 1960 | R | 4,462 | 7,219 | 11,736 | |
| 1956 | R | 4,088 | 7,024 | 11,158 | |
| 1952 | R | 3,567 | 8,134 | 11,797 | |
| 1948 | R | 4,571 | 5,922 | 10,685 | |
| 1944 | R | 4,187 | 6,343 | 10,594 | |
| 1940 | R | 5,988 | 6,585 | 12,698 | |
| 1936 | D | 7,966 | 4,946 | 12,939 | |
| 1932 | D | 6,353 | 4,926 | 11,619 | |
| 1928 | R | 2,108 | 8,951 | 11,240 | |
| 1924 | R | 2,556 | 5,552 | 10,108 | |
| 1920 | R | 3,454 | 5,830 | 9,638 | |
| 1916 | D | 5,519 | 4,079 | 10,361 | |
| 1912 | D | 2,557 | 781 | 6,398 | |
| 1908 | R | 2,772 | 3,235 | 6,306 | |
| 1904 | R | 1,489 | 3,264 | 5,298 | |
| 1900 | R | 2,982 | 3,184 | 6,291 | |
| 1896 | D | 3,048 | 2,515 | 5,619 | |
| 1892 | R | 0 | 4,058 | 7,695 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Sumner County, anchored by the small city of Wellington, delivered a 50-point Republican margin in 2024 — a figure consistent with the deep-red tilt of south-central Kansas's wheat-belt counties.
The Republican margin in Sumner County reached its widest at sixty-one points in 1928. The margin in 2024 was fifty points, in line with the county's deep historical pattern.
Sumner County's loyalty is rooted in its place. Median household income of $63,951, a 90% non-Hispanic-white share, and a population of 22,353 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 Trego County and Nemaha County.
