| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 672 | 3,798 | 4,555 | |
| 2020 | R | 704 | 3,856 | 4,675 | |
| 2016 | R | 621 | 3,759 | 4,682 | |
| 2012 | R | 1,166 | 3,152 | 4,455 | |
| 2008 | R | 1,476 | 2,789 | 4,397 | |
| 2004 | R | 1,245 | 3,285 | 4,617 | |
| 2000 | R | 1,011 | 2,984 | 4,353 | |
| 1996 | R | 1,300 | 1,953 | 4,042 | |
| 1992 | R | 1,323 | 2,274 | 5,017 | |
| 1988 | R | 1,843 | 3,013 | 4,902 | |
| 1984 | R | 1,729 | 3,705 | 5,510 | |
| 1980 | R | 1,209 | 3,224 | 4,741 | |
| 1976 | R | 1,298 | 1,982 | 3,316 | |
| 1972 | R | 784 | 2,567 | 3,456 | |
| 1968 | R | 730 | 2,039 | 2,939 | |
| 1964 | R | 1,310 | 1,540 | 2,850 | |
| 1960 | R | 844 | 2,395 | 3,239 | |
| 1956 | R | 666 | 2,555 | 3,227 | |
| 1952 | R | 512 | 2,994 | 3,524 | |
| 1948 | R | 643 | 2,219 | 2,948 | |
| 1944 | R | 445 | 2,504 | 2,956 | |
| 1940 | R | 567 | 3,341 | 3,914 | |
| 1936 | D | 1,924 | 1,142 | 3,619 | |
| 1932 | D | 2,491 | 480 | 2,993 | |
| 1928 | D | 1,619 | 971 | 2,593 | |
| 1924 | R | 70 | 522 | 2,086 | |
| 1920 | R | 172 | 1,786 | 2,047 | |
| 1916 | R | 353 | 730 | 1,138 | |
| 1912 | R | 142 | 147 | 737 | |
| 1908 | R | 96 | 430 | 530 | |
| 1904 | R | 17 | 252 | 270 | |
| 1900 | R | 41 | 269 | 310 | |
| 1896 | R | 28 | 115 | 143 | |
| 1892 | R | 0 | 28 | 85 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Mercer County, anchored by the coal-and-power economy around Beulah, recorded an R+68.6 presidential margin in 2024 — among the widest gaps in a state already dominated by one-party presidential voting.
The Republican margin in Mercer County reached its widest at eighty-seven points in 1904. The margin in 2024 was sixty-nine points, in line with the county's deep historical pattern.
Mercer County's loyalty is rooted in its place. Median household income of $80,946, a 92% non-Hispanic-white share, and a population of 8,337 together describe a community whose political habits are deeply settled. The county's voting pattern over the last decade is most similar to that of McKenzie County and Bottineau County.
