| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 17,469 | 22,765 | 40,676 | |
| 2020 | R | 16,894 | 20,899 | 38,479 | |
| 2016 | R | 13,517 | 19,315 | 35,045 | |
| 2012 | R | 15,890 | 17,571 | 33,887 | |
| 2008 | D | 16,796 | 16,402 | 33,465 | |
| 2004 | R | 14,080 | 17,920 | 32,298 | |
| 2000 | R | 10,719 | 14,799 | 26,795 | |
| 1996 | R | 10,345 | 10,685 | 23,616 | |
| 1992 | R | 8,405 | 10,578 | 25,090 | |
| 1988 | R | 6,603 | 14,454 | 21,280 | |
| 1984 | R | 4,743 | 14,200 | 19,027 | |
| 1980 | R | 4,365 | 12,077 | 18,546 | |
| 1976 | R | 6,143 | 9,876 | 16,249 | |
| 1972 | R | 4,610 | 11,536 | 16,312 | |
| 1968 | R | 4,942 | 8,642 | 14,071 | |
| 1964 | D | 8,024 | 5,908 | 13,932 | |
| 1960 | R | 5,630 | 9,156 | 14,786 | |
| 1956 | R | 3,131 | 9,902 | 13,038 | |
| 1952 | R | 3,755 | 9,567 | 13,322 | |
| 1948 | R | 3,822 | 7,152 | 11,039 | |
| 1944 | R | 5,325 | 6,188 | 11,515 | |
| 1940 | R | 5,653 | 6,115 | 11,768 | |
| 1936 | R | 5,150 | 6,219 | 11,522 | |
| 1932 | R | 4,911 | 6,048 | 10,988 | |
| 1928 | R | 3,689 | 6,762 | 10,462 | |
| 1924 | R | 3,217 | 5,996 | 9,399 | |
| 1920 | R | 3,464 | 5,628 | 9,115 | |
| 1916 | R | 2,310 | 2,579 | 5,001 | |
| 1912 | D | 1,862 | 1,741 | 4,728 | |
| 1908 | R | 1,692 | 2,916 | 4,775 | |
| 1904 | R | 1,761 | 2,867 | 4,754 | |
| 1900 | R | 1,819 | 3,099 | 5,054 | |
| 1896 | R | 978 | 3,465 | 4,768 | |
| 1892 | R | 2,472 | 2,663 | 5,267 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Belknap County wraps around Lake Winnipesaukee, drawing seasonal tourism and retirees alongside working-class manufacturing towns. That mix has produced a consistent Republican lean in recent cycles, with the 2024 presidential margin reaching double digits.
The county's recent history is a story of close margins. The Democratic margin reached fifteen points in 1964; the Republican margin reached fifty-two points in 1896. Most other elections have been decided by single-digit points.
Belknap County's demographics — a population of 64,659, a 93% non-Hispanic-white share, a median household income of $92,783 — 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 Berrien County and Sarasota County.