| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 3,400 | 6,068 | 9,639 | |
| 2020 | R | 3,547 | 6,009 | 9,742 | |
| 2016 | R | 3,084 | 5,205 | 9,002 | |
| 2012 | R | 4,144 | 4,569 | 8,866 | |
| 2008 | D | 4,202 | 4,188 | 8,546 | |
| 2004 | R | 3,841 | 4,544 | 8,454 | |
| 2000 | R | 3,230 | 3,894 | 7,413 | |
| 1996 | D | 3,354 | 3,042 | 7,035 | |
| 1992 | R | 2,560 | 2,656 | 6,965 | |
| 1988 | D | 3,338 | 3,247 | 6,685 | |
| 1984 | R | 2,815 | 4,352 | 7,251 | |
| 1980 | R | 2,606 | 4,153 | 7,522 | |
| 1976 | R | 3,367 | 3,926 | 7,411 | |
| 1972 | R | 2,578 | 4,202 | 6,964 | |
| 1968 | R | 2,586 | 4,133 | 7,111 | |
| 1964 | D | 4,261 | 2,828 | 7,102 | |
| 1960 | R | 2,828 | 4,944 | 7,790 | |
| 1956 | R | 2,753 | 4,875 | 7,777 | |
| 1952 | R | 2,514 | 5,625 | 8,362 | |
| 1948 | R | 3,030 | 3,659 | 6,978 | |
| 1944 | R | 3,119 | 3,959 | 7,340 | |
| 1940 | R | 3,649 | 4,696 | 8,488 | |
| 1936 | D | 4,163 | 3,360 | 7,712 | |
| 1932 | D | 4,376 | 2,628 | 7,499 | |
| 1928 | R | 3,075 | 4,091 | 7,196 | |
| 1924 | R | 1,458 | 3,549 | 6,837 | |
| 1920 | R | 2,019 | 4,892 | 6,997 | |
| 1916 | R | 1,763 | 2,484 | 4,290 | |
| 1912 | D | 1,841 | 1,237 | 4,022 | |
| 1908 | R | 1,907 | 2,230 | 4,241 | |
| 1904 | R | 1,891 | 2,303 | 4,361 | |
| 1900 | R | 1,983 | 2,336 | 4,433 | |
| 1896 | R | 1,956 | 2,391 | 4,446 | |
| 1892 | D | 2,157 | 1,672 | 3,967 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Iowa County sits in a stretch of small agricultural communities where population has drifted downward for decades, a pattern that correlates strongly with the lopsided presidential margins the county has recorded in recent elections.
The Republican margin in Iowa County reached its widest at forty-one points in 1920. The margin in 2024 was twenty-eight points, in line with the county's deep historical pattern.
Iowa County's loyalty is rooted in its place. Median household income of $71,223, a 94% non-Hispanic-white share, and a population of 16,507 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 Marshall County and Franklin County.
