| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 7,367 | 9,734 | 17,322 | |
| 2020 | R | 7,640 | 8,617 | 16,544 | |
| 2016 | R | 6,563 | 7,952 | 15,627 | |
| 2012 | D | 9,095 | 6,342 | 15,699 | |
| 2008 | D | 9,532 | 6,558 | 16,259 | |
| 2004 | D | 8,585 | 8,143 | 16,925 | |
| 2000 | R | 6,570 | 7,329 | 14,600 | |
| 1996 | D | 7,191 | 4,703 | 14,137 | |
| 1992 | D | 6,559 | 5,271 | 15,804 | |
| 1988 | R | 4,981 | 8,763 | 13,840 | |
| 1984 | R | 4,004 | 10,013 | 14,057 | |
| 1980 | R | 4,749 | 8,724 | 14,520 | |
| 1976 | D | 7,385 | 7,094 | 14,638 | |
| 1972 | R | 5,829 | 9,468 | 15,563 | |
| 1968 | D | 8,261 | 6,822 | 15,497 | |
| 1964 | D | 11,956 | 4,863 | 16,819 | |
| 1960 | D | 10,455 | 7,797 | 18,252 | |
| 1956 | R | 5,871 | 11,465 | 17,338 | |
| 1952 | R | 7,848 | 9,975 | 17,823 | |
| 1948 | D | 7,930 | 7,005 | 15,165 | |
| 1944 | D | 8,709 | 6,209 | 14,922 | |
| 1940 | D | 10,100 | 6,650 | 16,750 | |
| 1936 | D | 8,737 | 6,737 | 15,694 | |
| 1932 | D | 7,928 | 7,189 | 15,205 | |
| 1928 | R | 6,006 | 7,891 | 13,931 | |
| 1924 | R | 4,620 | 6,137 | 11,651 | |
| 1920 | R | 4,985 | 6,114 | 11,228 | |
| 1916 | D | 3,247 | 2,762 | 6,246 | |
| 1912 | D | 2,229 | 1,938 | 5,501 | |
| 1908 | R | 2,216 | 3,294 | 5,646 | |
| 1904 | R | 2,241 | 3,343 | 5,659 | |
| 1900 | R | 2,436 | 3,383 | 5,894 | |
| 1896 | R | 1,489 | 3,253 | 4,928 | |
| 1892 | D | 2,639 | 2,419 | 5,108 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Once a Democratic stronghold anchored by paper-mill towns, Coos County has moved consistently toward Republican presidential candidates since 2000, reflecting broader working-class realignment in rural New England's most sparsely populated corner.
The Democratic margin in Coos County has rarely exceeded forty-two points in modern history; the Republican margin has rarely exceeded forty-three points. 2024 delivered the county to the Republican candidate by fourteen points.
Coos County's demographics resemble the country more than they resemble most counties. A 93% non-Hispanic-white share, a 13% poverty rate, and a median household income of $57,677 — all within the broad national range. The county's voting pattern over the last decade is most similar to that of Cortland County and Isabella County.
