| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 2,376 | 2,329 | 4,870 | |
| 2020 | D | 2,562 | 2,186 | 4,891 | |
| 2016 | D | 2,058 | 1,763 | 4,206 | |
| 2012 | D | 2,860 | 1,448 | 4,460 | |
| 2008 | D | 3,402 | 1,502 | 5,074 | |
| 2004 | D | 2,700 | 1,725 | 4,543 | |
| 2000 | D | 2,672 | 1,493 | 4,534 | |
| 1996 | D | 3,331 | 883 | 5,010 | |
| 1992 | D | 3,174 | 832 | 5,269 | |
| 1988 | D | 3,185 | 1,168 | 4,406 | |
| 1984 | D | 3,539 | 1,901 | 5,505 | |
| 1980 | D | 3,077 | 1,905 | 5,638 | |
| 1976 | D | 3,859 | 2,197 | 6,176 | |
| 1972 | D | 3,979 | 2,373 | 6,604 | |
| 1968 | D | 4,208 | 1,554 | 6,074 | |
| 1964 | D | 4,835 | 1,415 | 6,259 | |
| 1960 | D | 5,149 | 2,188 | 7,344 | |
| 1956 | D | 3,792 | 3,551 | 7,343 | |
| 1952 | D | 4,162 | 3,001 | 7,217 | |
| 1948 | D | 3,862 | 2,036 | 6,212 | |
| 1944 | D | 4,347 | 2,176 | 6,556 | |
| 1940 | D | 4,916 | 2,397 | 7,345 | |
| 1936 | D | 4,813 | 1,640 | 6,549 | |
| 1932 | D | 3,893 | 2,198 | 6,204 | |
| 1928 | D | 3,184 | 2,695 | 5,901 | |
| 1924 | R | 1,611 | 1,937 | 5,467 | |
| 1920 | R | 1,567 | 3,130 | 5,219 | |
| 1916 | D | 4,171 | 1,860 | 6,143 | |
| 1912 | D | 1,197 | 1,060 | 2,860 | |
| 1908 | D | 1,611 | 1,377 | 3,153 | |
| 1904 | R | 1,504 | 1,666 | 3,425 | |
| 1900 | D | 3,395 | 1,636 | 5,193 | |
| 1896 | D | 4,916 | 446 | 5,370 | |
| 1892 | D | 2,152 | 1,930 | 5,441 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Deer Lodge County, home to Anaconda and its smelter legacy, leans modestly Democratic in a heavily Republican state — a holdover from organized labor's deep roots in Montana's copper-mining era.
The county's recent history is a story of close margins. The Democratic margin reached eighty-three points in 1896; the Republican margin reached thirty points in 1920. Most other elections have been decided by single-digit points.
Deer Lodge County's demographics — a population of 9,597, a 90% non-Hispanic-white share, a median household income of $57,527 — 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 Lake County and Silver Bow County.
