| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 48,452 | 39,673 | 90,375 | |
| 2020 | D | 50,064 | 38,646 | 91,326 | |
| 2016 | D | 41,125 | 36,200 | 83,868 | |
| 2012 | D | 39,847 | 37,404 | 79,422 | |
| 2008 | D | 47,062 | 36,849 | 85,251 | |
| 2004 | R | 37,643 | 37,801 | 76,046 | |
| 2000 | D | 28,811 | 28,426 | 59,609 | |
| 1996 | D | 24,984 | 22,047 | 51,920 | |
| 1992 | D | 26,176 | 19,405 | 57,890 | |
| 1988 | D | 24,370 | 22,948 | 47,458 | |
| 1984 | R | 19,364 | 26,600 | 45,964 | |
| 1980 | D | 18,527 | 16,313 | 38,837 | |
| 1976 | D | 17,674 | 16,373 | 34,893 | |
| 1972 | R | 13,666 | 17,488 | 31,154 | |
| 1968 | R | 11,771 | 11,917 | 25,703 | |
| 1964 | D | 14,758 | 7,695 | 22,453 | |
| 1960 | D | 11,514 | 10,453 | 21,967 | |
| 1956 | D | 10,404 | 8,197 | 18,601 | |
| 1952 | D | 10,206 | 7,545 | 17,785 | |
| 1948 | D | 10,200 | 4,289 | 14,653 | |
| 1944 | D | 9,704 | 4,195 | 13,929 | |
| 1940 | D | 11,615 | 4,869 | 16,543 | |
| 1936 | D | 11,241 | 3,624 | 14,926 | |
| 1932 | D | 11,554 | 3,241 | 14,979 | |
| 1928 | D | 8,422 | 4,876 | 13,319 | |
| 1924 | D | 8,657 | 3,547 | 12,373 | |
| 1920 | D | 8,748 | 4,077 | 12,890 | |
| 1916 | D | 5,601 | 2,180 | 7,838 | |
| 1912 | D | 5,027 | 1,350 | 7,158 | |
| 1908 | D | 5,041 | 2,149 | 7,254 | |
| 1904 | D | 4,375 | 1,857 | 6,327 | |
| 1900 | D | 4,793 | 1,672 | 6,589 | |
| 1896 | D | 5,075 | 1,705 | 6,822 | |
| 1892 | D | 4,054 | 1,495 | 5,806 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Home to the University of Missouri, Boone County posts Democratic margins unusual for rural Missouri — Biden carried it by double digits in 2020, and Harris held similar ground in 2024, anchored by student and faculty turnout in Columbia.
The county's recent history is a story of close margins. The Democratic margin reached fifty-five points in 1932; the Republican margin reached sixteen points in 1984. Most other elections have been decided by single-digit points.
Boone County's demographics — a population of 188,043, a 77% non-Hispanic-white share, a median household income of $72,758 — 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 Chatham County and Missoula County.
