| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 8,402 | 20,480 | 29,495 | |
| 2020 | R | 9,215 | 20,683 | 30,465 | |
| 2016 | R | 7,694 | 18,750 | 28,351 | |
| 2012 | R | 9,732 | 15,876 | 26,271 | |
| 2008 | R | 13,582 | 17,824 | 31,870 | |
| 2004 | R | 13,238 | 17,111 | 30,588 | |
| 2000 | D | 13,009 | 12,948 | 26,578 | |
| 1996 | D | 14,746 | 8,857 | 26,843 | |
| 1992 | D | 15,480 | 9,687 | 30,341 | |
| 1988 | D | 17,005 | 13,364 | 30,418 | |
| 1984 | R | 14,969 | 19,400 | 34,437 | |
| 1980 | D | 18,813 | 14,251 | 34,602 | |
| 1976 | D | 21,467 | 15,172 | 36,639 | |
| 1972 | R | 12,910 | 22,196 | 35,106 | |
| 1968 | D | 18,872 | 13,703 | 34,809 | |
| 1964 | D | 25,683 | 9,986 | 35,669 | |
| 1960 | D | 20,727 | 18,378 | 39,105 | |
| 1956 | R | 17,541 | 21,860 | 39,401 | |
| 1952 | R | 20,527 | 21,193 | 41,720 | |
| 1948 | D | 21,109 | 14,534 | 35,757 | |
| 1944 | D | 18,028 | 14,408 | 32,436 | |
| 1940 | D | 22,570 | 17,087 | 39,657 | |
| 1936 | D | 24,361 | 14,180 | 38,678 | |
| 1932 | D | 18,081 | 14,641 | 33,354 | |
| 1928 | R | 12,483 | 17,502 | 30,331 | |
| 1924 | R | 13,470 | 15,165 | 30,710 | |
| 1920 | R | 10,206 | 13,784 | 24,759 | |
| 1916 | R | 5,970 | 6,262 | 12,816 | |
| 1912 | D | 4,378 | 1,754 | 10,652 | |
| 1908 | R | 4,004 | 4,946 | 9,439 | |
| 1904 | R | 2,921 | 5,075 | 8,452 | |
| 1900 | D | 3,918 | 2,678 | 6,721 | |
| 1896 | R | 2,485 | 3,027 | 5,551 | |
| 1892 | R | 2,237 | 2,567 | 5,004 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Harrison County's R+40.9 margin in 2024 reflects a broader realignment across north-central West Virginia, where a historically Democratic coal and industrial workforce has shifted decisively toward Republican candidates at every level since the 2000s.
The unraveling was not abrupt. The Democratic margin in Harrison County peaked at forty-four points in 1964; it narrowed steadily over the late twentieth century. The 2004 election delivered the county to the Republican party for the first time in many years, by a margin of thirteen points. By 2024, the margin had widened further.
The economic and demographic context is severe. Harrison County's median household income of $60,377 is among the lowest of any county in the United States; 14% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Ballard County and Foard County.