| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 8,212 | 11,152 | 19,752 | |
| 2020 | R | 9,372 | 10,823 | 20,671 | |
| 2016 | R | 8,368 | 9,584 | 19,623 | |
| 2012 | D | 11,323 | 8,168 | 19,865 | |
| 2008 | D | 10,920 | 7,929 | 19,119 | |
| 2004 | D | 9,542 | 9,020 | 18,717 | |
| 2000 | D | 8,058 | 7,483 | 16,076 | |
| 1996 | D | 7,674 | 5,858 | 15,386 | |
| 1992 | D | 7,089 | 6,087 | 16,864 | |
| 1988 | D | 7,059 | 6,904 | 14,102 | |
| 1984 | R | 5,986 | 9,069 | 15,168 | |
| 1980 | R | 5,597 | 7,829 | 15,145 | |
| 1976 | R | 6,567 | 7,697 | 14,496 | |
| 1972 | R | 4,917 | 8,436 | 13,642 | |
| 1968 | R | 4,726 | 7,361 | 12,874 | |
| 1964 | D | 8,020 | 5,547 | 13,577 | |
| 1960 | R | 6,135 | 8,555 | 14,698 | |
| 1956 | R | 5,718 | 8,552 | 14,298 | |
| 1952 | R | 5,772 | 9,361 | 15,196 | |
| 1948 | R | 5,466 | 6,003 | 11,615 | |
| 1944 | R | 4,801 | 7,104 | 11,963 | |
| 1940 | R | 5,825 | 8,543 | 14,421 | |
| 1936 | D | 6,593 | 6,332 | 13,313 | |
| 1932 | D | 6,423 | 6,160 | 12,917 | |
| 1928 | R | 4,055 | 8,604 | 12,757 | |
| 1924 | R | 1,963 | 7,731 | 11,917 | |
| 1920 | R | 2,293 | 8,115 | 11,544 | |
| 1916 | R | 2,694 | 3,929 | 7,242 | |
| 1912 | D | 2,679 | 789 | 7,110 | |
| 1908 | R | 3,038 | 3,525 | 7,131 | |
| 1904 | R | 2,555 | 4,036 | 7,076 | |
| 1900 | R | 3,021 | 3,905 | 7,110 | |
| 1896 | R | 2,863 | 3,627 | 6,592 | |
| 1892 | D | 2,964 | 2,726 | 5,874 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Muscatine County, anchored by its industrial river city, voted within single digits of the national average as recently as 2008 but has since moved sharply toward Republican margins, reflecting broader rural and working-class realignment across the Iowa River corridor.
The Democratic margin in Muscatine County has rarely exceeded twenty-seven points in modern history; the Republican margin has rarely exceeded fifty points. 2024 delivered the county to the Republican candidate by fifteen points.
Muscatine County's demographics resemble the country more than they resemble most counties. A 81% non-Hispanic-white share, a 14% poverty rate, and a median household income of $69,396 — all within the broad national range. The county's voting pattern over the last decade is most similar to that of Lafayette County and Whiteside County.