| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 10,966 | 15,922 | 27,306 | |
| 2020 | R | 10,998 | 14,142 | 25,608 | |
| 2016 | R | 10,051 | 12,350 | 24,368 | |
| 2012 | D | 13,594 | 10,255 | 24,248 | |
| 2008 | D | 14,875 | 9,068 | 24,320 | |
| 2004 | D | 12,864 | 12,208 | 25,264 | |
| 2000 | D | 10,691 | 10,240 | 21,956 | |
| 1996 | D | 9,203 | 7,021 | 19,215 | |
| 1992 | D | 8,914 | 7,678 | 23,157 | |
| 1988 | R | 9,421 | 10,049 | 19,580 | |
| 1984 | R | 7,892 | 13,430 | 21,460 | |
| 1980 | R | 8,406 | 13,298 | 23,824 | |
| 1976 | R | 9,639 | 12,016 | 22,207 | |
| 1972 | R | 6,915 | 11,873 | 19,061 | |
| 1968 | R | 5,414 | 10,789 | 17,264 | |
| 1964 | D | 9,309 | 7,872 | 17,211 | |
| 1960 | R | 7,678 | 11,564 | 19,258 | |
| 1956 | R | 5,208 | 11,648 | 16,958 | |
| 1952 | R | 4,197 | 14,327 | 18,556 | |
| 1948 | R | 6,575 | 8,299 | 15,089 | |
| 1944 | R | 6,091 | 10,226 | 16,345 | |
| 1940 | R | 7,458 | 11,143 | 18,759 | |
| 1936 | D | 9,170 | 7,196 | 17,503 | |
| 1932 | D | 9,701 | 5,986 | 15,919 | |
| 1928 | R | 6,630 | 10,052 | 16,794 | |
| 1924 | R | 1,518 | 5,714 | 14,169 | |
| 1920 | R | 1,971 | 9,638 | 11,911 | |
| 1916 | R | 3,459 | 4,718 | 8,382 | |
| 1912 | D | 3,615 | 3,283 | 7,886 | |
| 1908 | R | 3,696 | 4,989 | 9,056 | |
| 1904 | R | 2,886 | 5,804 | 8,995 | |
| 1900 | R | 3,254 | 5,609 | 9,172 | |
| 1896 | R | 3,683 | 5,315 | 9,260 | |
| 1892 | R | 3,685 | 4,217 | 8,396 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Grant County sits along the Mississippi River bluffs and has shifted from a competitive battleground to a reliably Republican-leaning county over the past decade, moving roughly 20 points toward the GOP since Barack Obama carried it twice.
The Democratic margin in Grant County has rarely exceeded twenty-four points in modern history; the Republican margin has rarely exceeded sixty-four points. 2024 delivered the county to the Republican candidate by eighteen points.
Grant County's demographics resemble the country more than they resemble most counties. A 94% non-Hispanic-white share, a 13% poverty rate, and a median household income of $66,858 — all within the broad national range. The county's voting pattern over the last decade is most similar to that of Lafayette County and LaPorte County.