| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 5,571 | 8,799 | 14,607 | |
| 2020 | R | 5,958 | 8,294 | 14,546 | |
| 2016 | R | 5,356 | 7,208 | 13,691 | |
| 2012 | D | 6,763 | 6,405 | 13,346 | |
| 2008 | D | 6,940 | 5,741 | 12,871 | |
| 2004 | R | 6,025 | 6,665 | 12,779 | |
| 2000 | R | 5,169 | 5,675 | 11,175 | |
| 1996 | D | 5,023 | 4,213 | 10,172 | |
| 1992 | D | 4,774 | 4,482 | 11,714 | |
| 1988 | R | 4,961 | 5,079 | 10,099 | |
| 1984 | R | 4,084 | 6,895 | 11,055 | |
| 1980 | R | 3,527 | 6,706 | 11,318 | |
| 1976 | R | 4,203 | 6,252 | 10,685 | |
| 1972 | R | 3,122 | 6,333 | 9,611 | |
| 1968 | R | 2,481 | 5,604 | 8,523 | |
| 1964 | D | 5,045 | 3,880 | 8,939 | |
| 1960 | R | 3,234 | 6,504 | 9,742 | |
| 1956 | R | 2,892 | 5,930 | 8,831 | |
| 1952 | R | 2,363 | 6,806 | 9,183 | |
| 1948 | R | 3,502 | 3,837 | 7,433 | |
| 1944 | R | 2,764 | 4,861 | 7,642 | |
| 1940 | R | 3,103 | 5,374 | 8,495 | |
| 1936 | D | 5,058 | 3,220 | 8,470 | |
| 1932 | D | 5,411 | 2,520 | 7,994 | |
| 1928 | R | 3,146 | 3,879 | 7,043 | |
| 1924 | R | 911 | 3,532 | 7,310 | |
| 1920 | R | 902 | 6,287 | 7,269 | |
| 1916 | R | 1,132 | 2,684 | 3,847 | |
| 1912 | D | 1,944 | 1,013 | 3,764 | |
| 1908 | D | 1,925 | 1,656 | 3,656 | |
| 1904 | R | 1,783 | 1,927 | 3,792 | |
| 1900 | R | 1,929 | 2,178 | 4,152 | |
| 1896 | R | 1,704 | 2,116 | 3,917 | |
| 1892 | D | 1,933 | 1,555 | 3,580 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Bremer County's 2024 presidential margin of R+22.1 reflects a steady rightward shift in this northeastern Iowa county, where small manufacturing towns and agricultural land have both trended away from their earlier competitive patterns.
The county's recent history is a story of close margins. The Democratic margin reached thirty-six points in 1932; the Republican margin reached seventy-four points in 1920. Most other elections have been decided by single-digit points.
Bremer County's demographics — a population of 25,204, a 93% non-Hispanic-white share, a median household income of $86,784 — situate the county close to national averages on several dimensions. The county's voting pattern over the last decade is most similar to that of Monroe County and Sargent County.