| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 328 | 1,344 | 1,692 | |
| 2020 | R | 343 | 1,322 | 1,700 | |
| 2016 | R | 340 | 1,150 | 1,573 | |
| 2012 | R | 552 | 927 | 1,530 | |
| 2008 | R | 585 | 950 | 1,572 | |
| 2004 | R | 541 | 1,072 | 1,643 | |
| 2000 | R | 564 | 1,072 | 1,705 | |
| 1996 | R | 567 | 822 | 1,672 | |
| 1992 | R | 568 | 736 | 1,900 | |
| 1988 | R | 839 | 915 | 1,771 | |
| 1984 | R | 701 | 1,144 | 1,862 | |
| 1980 | R | 578 | 1,254 | 1,970 | |
| 1976 | D | 1,078 | 935 | 2,093 | |
| 1972 | R | 811 | 1,099 | 1,910 | |
| 1968 | R | 851 | 955 | 1,986 | |
| 1964 | D | 1,632 | 762 | 2,394 | |
| 1960 | D | 1,427 | 1,131 | 2,558 | |
| 1956 | R | 1,219 | 1,429 | 2,648 | |
| 1952 | R | 1,166 | 1,784 | 2,950 | |
| 1948 | D | 1,608 | 1,003 | 2,611 | |
| 1944 | D | 1,584 | 1,309 | 2,893 | |
| 1940 | D | 1,888 | 1,494 | 3,382 | |
| 1936 | D | 2,701 | 1,294 | 4,043 | |
| 1932 | D | 2,670 | 952 | 3,692 | |
| 1928 | D | 1,733 | 1,675 | 3,435 | |
| 1924 | R | 1,048 | 1,182 | 2,964 | |
| 1920 | R | 848 | 1,582 | 2,595 | |
| 1916 | D | 1,208 | 706 | 2,028 | |
| 1912 | D | 673 | 455 | 1,861 | |
| 1908 | D | 925 | 776 | 1,774 | |
| 1904 | R | 140 | 809 | 1,437 | |
| 1900 | D | 743 | 503 | 1,302 | |
| 1896 | D | 859 | 432 | 1,320 | |
| 1892 | D | 453 | 122 | 1,229 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Sherman County's small, agriculturally rooted population has delivered Republican presidential margins above 60 points, placing it among the most one-sided counties in a state already tilted heavily toward GOP presidential candidates.
The Democratic margin in Sherman County peaked at forty-seven points in 1932. By 1980 the county had flipped, voting Republican for the first time in many years. The 2024 margin was sixty points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Sherman County's median household income of $63,578 sits well below state and national norms, and 9% 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 Mahaska County and Howard County.