| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 9,110 | 19,557 | 28,857 | |
| 2020 | R | 9,939 | 18,871 | 29,322 | |
| 2016 | R | 8,083 | 16,699 | 26,255 | |
| 2012 | R | 11,273 | 13,282 | 25,040 | |
| 2008 | R | 12,094 | 14,619 | 27,184 | |
| 2004 | R | 11,675 | 16,024 | 28,310 | |
| 2000 | R | 12,224 | 14,147 | 27,705 | |
| 1996 | D | 11,910 | 10,085 | 26,626 | |
| 1992 | R | 10,880 | 12,052 | 29,939 | |
| 1988 | R | 12,694 | 15,104 | 28,022 | |
| 1984 | R | 10,346 | 18,827 | 29,258 | |
| 1980 | R | 11,497 | 14,105 | 27,888 | |
| 1976 | R | 12,875 | 15,362 | 28,377 | |
| 1972 | R | 9,487 | 20,194 | 29,767 | |
| 1968 | R | 10,940 | 15,192 | 27,665 | |
| 1964 | D | 20,136 | 10,159 | 30,317 | |
| 1960 | R | 14,977 | 17,758 | 32,768 | |
| 1956 | R | 8,789 | 22,246 | 31,035 | |
| 1952 | R | 11,599 | 20,980 | 32,668 | |
| 1948 | R | 12,577 | 14,688 | 28,338 | |
| 1944 | R | 12,381 | 15,656 | 28,085 | |
| 1940 | R | 13,013 | 17,590 | 30,657 | |
| 1936 | R | 12,847 | 15,941 | 29,129 | |
| 1932 | R | 11,194 | 15,158 | 26,790 | |
| 1928 | R | 10,654 | 18,624 | 29,709 | |
| 1924 | R | 6,464 | 15,625 | 23,563 | |
| 1920 | R | 6,507 | 14,310 | 21,924 | |
| 1916 | R | 6,271 | 7,934 | 14,580 | |
| 1912 | D | 5,122 | 4,665 | 13,580 | |
| 1908 | R | 5,918 | 8,202 | 14,679 | |
| 1904 | R | 5,827 | 8,319 | 14,645 | |
| 1900 | R | 5,401 | 8,100 | 14,022 | |
| 1896 | R | 5,027 | 8,096 | 13,545 | |
| 1892 | R | 5,526 | 6,219 | 12,454 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Herkimer's population of roughly 64,000 spans the Mohawk Valley and Adirondack foothills, and its 2024 presidential margin of R+36.4 reflects a long-running rural realignment that has widened steadily over successive election cycles.
The Democratic margin in Herkimer County peaked at thirty-three points in 1964. By 2000 the county had flipped, voting Republican for the first time in many years. The 2024 margin was thirty-six points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Herkimer County's median household income of $68,515 sits well below state and national norms, and 13% of residents live below the federal poverty line. The shift here is part of a broader realignment of working-class places across the country. The county's voting pattern over the last decade is most similar to that of Fulton County and Waseca County.