| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 3,766 | 6,790 | 10,750 | |
| 2020 | R | 4,169 | 6,420 | 10,774 | |
| 2016 | R | 3,970 | 5,510 | 10,377 | |
| 2012 | D | 5,911 | 4,450 | 10,535 | |
| 2008 | D | 6,050 | 4,139 | 10,338 | |
| 2004 | D | 5,608 | 4,797 | 10,475 | |
| 2000 | D | 5,045 | 4,092 | 9,410 | |
| 1996 | D | 4,997 | 3,043 | 8,951 | |
| 1992 | D | 4,166 | 3,313 | 9,654 | |
| 1988 | D | 4,778 | 3,495 | 8,321 | |
| 1984 | R | 4,129 | 4,965 | 9,152 | |
| 1980 | R | 3,605 | 5,041 | 9,422 | |
| 1976 | R | 4,258 | 4,794 | 9,223 | |
| 1972 | R | 3,609 | 5,277 | 9,048 | |
| 1968 | R | 3,670 | 4,541 | 8,674 | |
| 1964 | D | 5,621 | 3,187 | 8,823 | |
| 1960 | R | 4,251 | 5,179 | 9,433 | |
| 1956 | R | 3,513 | 5,512 | 9,035 | |
| 1952 | R | 3,019 | 6,431 | 9,484 | |
| 1948 | R | 4,127 | 4,310 | 8,523 | |
| 1944 | R | 3,841 | 4,653 | 8,508 | |
| 1940 | R | 4,649 | 5,630 | 10,309 | |
| 1936 | D | 5,025 | 4,734 | 9,894 | |
| 1932 | D | 5,004 | 4,401 | 9,500 | |
| 1928 | R | 3,099 | 5,885 | 9,004 | |
| 1924 | R | 1,780 | 5,459 | 8,651 | |
| 1920 | R | 1,600 | 6,334 | 7,997 | |
| 1916 | R | 1,808 | 3,000 | 4,855 | |
| 1912 | D | 1,866 | 1,271 | 4,719 | |
| 1908 | R | 1,889 | 2,552 | 4,577 | |
| 1904 | R | 1,545 | 2,798 | 4,592 | |
| 1900 | R | 2,053 | 2,958 | 5,194 | |
| 1896 | R | 2,233 | 2,865 | 5,181 | |
| 1892 | R | 2,166 | 2,498 | 4,817 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Buchanan County's population of roughly 21,000 is anchored by Independence, the county seat, and sustained by agriculture and small manufacturing. Its R+28 margin in 2024 reflects a decades-long rural realignment that has outpaced neighboring counties.
The county's recent history is a story of close margins. The Democratic margin reached twenty-eight points in 1964; the Republican margin reached fifty-nine points in 1920. Most other elections have been decided by single-digit points.
Buchanan County's demographics — a population of 20,694, a 96% non-Hispanic-white share, a median household income of $78,236 — 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 Worth County and Jackson County.