| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 1,348 | 1,526 | 3,019 | |
| 2020 | D | 1,589 | 1,469 | 3,117 | |
| 2016 | R | 1,202 | 1,268 | 2,684 | |
| 2012 | D | 1,616 | 1,178 | 2,859 | |
| 2008 | D | 1,702 | 1,139 | 2,924 | |
| 2004 | R | 1,300 | 1,424 | 2,768 | |
| 2000 | R | 1,246 | 1,410 | 2,759 | |
| 1996 | D | 1,316 | 1,127 | 2,893 | |
| 1992 | D | 1,355 | 971 | 3,046 | |
| 1988 | D | 1,460 | 1,402 | 2,912 | |
| 1984 | R | 1,229 | 1,736 | 2,997 | |
| 1980 | R | 1,107 | 1,686 | 2,995 | |
| 1976 | D | 1,356 | 1,349 | 2,739 | |
| 1972 | R | 1,151 | 1,513 | 2,779 | |
| 1968 | R | 1,198 | 1,291 | 2,655 | |
| 1964 | D | 1,742 | 961 | 2,703 | |
| 1960 | D | 1,569 | 1,290 | 2,876 | |
| 1956 | R | 1,438 | 1,460 | 2,898 | |
| 1952 | R | 1,207 | 1,890 | 3,106 | |
| 1948 | D | 1,669 | 997 | 2,748 | |
| 1944 | D | 1,469 | 990 | 2,479 | |
| 1940 | D | 2,129 | 1,165 | 3,327 | |
| 1936 | D | 2,166 | 851 | 3,074 | |
| 1932 | D | 1,977 | 1,063 | 3,160 | |
| 1928 | R | 1,160 | 1,537 | 2,714 | |
| 1924 | R | 337 | 827 | 1,808 | |
| 1920 | R | 848 | 1,720 | 2,753 | |
| 1916 | D | 1,261 | 857 | 2,190 | |
| 1912 | D | 318 | 204 | 1,137 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Blaine County's Fort Belknap Indian Reservation shapes its electorate in ways that set it apart from surrounding Hi-Line counties, and the 2024 presidential margin of R+5.9 reflects a competitive mix absent in most of rural Montana.
The county's recent history is a story of close margins. The Democratic margin reached forty-three points in 1936; the Republican margin reached thirty-two points in 1920. Most other elections have been decided by single-digit points.
Blaine County's demographics — a population of 6,949, a 44% non-Hispanic-white share, a median household income of $64,813 — 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 Winneshiek County and Pasquotank County.