| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 4,067 | 5,758 | 10,013 | |
| 2020 | R | 4,306 | 5,657 | 10,140 | |
| 2016 | R | 4,304 | 4,946 | 9,916 | |
| 2012 | D | 5,357 | 4,424 | 9,975 | |
| 2008 | D | 5,519 | 4,340 | 10,031 | |
| 2004 | D | 5,043 | 4,965 | 10,091 | |
| 2000 | R | 4,222 | 4,396 | 8,980 | |
| 1996 | D | 4,183 | 3,221 | 8,214 | |
| 1992 | D | 4,056 | 3,245 | 9,047 | |
| 1988 | D | 4,876 | 3,683 | 8,625 | |
| 1984 | R | 4,103 | 4,715 | 8,889 | |
| 1980 | R | 3,529 | 4,598 | 9,102 | |
| 1976 | D | 4,360 | 4,194 | 8,735 | |
| 1972 | R | 3,718 | 4,785 | 8,648 | |
| 1968 | R | 3,250 | 4,470 | 8,112 | |
| 1964 | D | 5,213 | 3,109 | 8,334 | |
| 1960 | R | 3,671 | 5,232 | 8,904 | |
| 1956 | R | 3,602 | 5,145 | 8,749 | |
| 1952 | R | 3,318 | 6,105 | 9,498 | |
| 1948 | D | 4,324 | 3,888 | 8,385 | |
| 1944 | D | 4,234 | 4,186 | 8,461 | |
| 1940 | D | 4,794 | 4,773 | 9,611 | |
| 1936 | D | 4,745 | 4,037 | 8,996 | |
| 1932 | D | 4,649 | 3,490 | 8,355 | |
| 1928 | R | 2,787 | 5,212 | 8,150 | |
| 1924 | R | 1,428 | 4,414 | 8,239 | |
| 1920 | R | 2,125 | 5,806 | 8,130 | |
| 1916 | R | 1,880 | 2,748 | 4,788 | |
| 1912 | D | 1,631 | 902 | 4,545 | |
| 1908 | R | 1,661 | 2,794 | 4,678 | |
| 1904 | R | 1,212 | 3,137 | 4,649 | |
| 1900 | R | 1,765 | 3,199 | 5,074 | |
| 1896 | R | 2,013 | 2,969 | 5,076 | |
| 1892 | R | 1,776 | 2,359 | 4,447 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Poweshiek County anchors a liberal-arts institution with a national reputation inside a rural Iowa landscape that voted Republican by nearly 17 points in 2024, a gap that illustrates how college towns no longer reliably offset surrounding agricultural precincts.
The Democratic margin in Poweshiek County has rarely exceeded twenty-five points in modern history; the Republican margin has rarely exceeded forty-five points. 2024 delivered the county to the Republican candidate by seventeen points.
Poweshiek County's demographics resemble the country more than they resemble most counties. A 90% non-Hispanic-white share, a 11% poverty rate, and a median household income of $67,391 — all within the broad national range. The county's voting pattern over the last decade is most similar to that of Marshall County and Conejos County.