| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,995 | 6,439 | 9,600 | |
| 2020 | R | 3,275 | 6,507 | 9,982 | |
| 2016 | R | 2,904 | 5,779 | 9,500 | |
| 2012 | R | 4,460 | 5,035 | 9,697 | |
| 2008 | R | 4,349 | 4,822 | 9,377 | |
| 2004 | R | 4,127 | 5,220 | 9,457 | |
| 2000 | R | 3,907 | 4,476 | 8,671 | |
| 1996 | D | 3,798 | 3,478 | 8,275 | |
| 1992 | D | 3,544 | 3,435 | 8,628 | |
| 1988 | R | 3,754 | 3,951 | 7,758 | |
| 1984 | R | 3,377 | 4,516 | 7,955 | |
| 1980 | R | 3,317 | 4,430 | 8,462 | |
| 1976 | D | 3,882 | 3,848 | 7,887 | |
| 1972 | R | 2,721 | 5,066 | 7,884 | |
| 1968 | R | 2,532 | 4,613 | 7,659 | |
| 1964 | D | 4,223 | 3,247 | 7,482 | |
| 1960 | R | 2,839 | 5,531 | 8,377 | |
| 1956 | R | 2,667 | 5,818 | 8,495 | |
| 1952 | R | 2,438 | 6,424 | 8,931 | |
| 1948 | R | 3,042 | 4,620 | 7,805 | |
| 1944 | R | 2,741 | 5,208 | 7,998 | |
| 1940 | R | 2,837 | 5,893 | 8,749 | |
| 1936 | R | 3,542 | 4,480 | 8,271 | |
| 1932 | D | 4,518 | 3,398 | 8,074 | |
| 1928 | R | 2,053 | 5,160 | 7,278 | |
| 1924 | R | 1,344 | 4,536 | 7,296 | |
| 1920 | R | 1,939 | 5,254 | 7,306 | |
| 1916 | R | 1,728 | 2,470 | 4,259 | |
| 1912 | R | 1,580 | 1,663 | 4,251 | |
| 1908 | R | 1,606 | 2,653 | 4,356 | |
| 1904 | R | 1,259 | 2,647 | 4,106 | |
| 1900 | R | 1,907 | 2,794 | 4,847 | |
| 1896 | R | 2,092 | 2,774 | 4,969 | |
| 1892 | R | 1,710 | 2,390 | 4,382 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Henry County's blend of small manufacturing towns and agricultural land has tracked a steady rightward shift over two decades, with 2024's R+35.9 margin reflecting a pattern consistent across Iowa's non-metro southeast corridor.
The Republican margin in Henry County reached its widest at forty-five points in 1920. The margin in 2024 was thirty-six points, in line with the county's deep historical pattern.
Henry County's loyalty is rooted in its place. Median household income of $67,436, a 88% non-Hispanic-white share, and a population of 20,004 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 Switzerland County and Todd County.
