| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 9,231 | 22,141 | 32,137 | |
| 2020 | R | 9,158 | 20,886 | 30,641 | |
| 2016 | R | 7,875 | 21,270 | 30,369 | |
| 2012 | R | 9,805 | 19,230 | 29,850 | |
| 2008 | R | 10,693 | 18,405 | 29,742 | |
| 2004 | R | 10,576 | 18,980 | 29,855 | |
| 2000 | R | 10,894 | 14,656 | 26,371 | |
| 1996 | R | 11,025 | 12,136 | 26,001 | |
| 1992 | R | 11,501 | 13,862 | 30,595 | |
| 1988 | R | 11,844 | 17,462 | 29,503 | |
| 1984 | R | 11,143 | 19,763 | 31,223 | |
| 1980 | R | 12,167 | 17,512 | 31,484 | |
| 1976 | D | 15,967 | 15,435 | 31,402 | |
| 1972 | R | 10,808 | 20,687 | 32,048 | |
| 1968 | R | 13,227 | 13,561 | 31,910 | |
| 1964 | D | 20,425 | 12,384 | 32,809 | |
| 1960 | R | 13,701 | 20,489 | 34,190 | |
| 1956 | R | 10,775 | 20,239 | 31,014 | |
| 1952 | R | 14,529 | 19,186 | 33,762 | |
| 1948 | D | 14,398 | 14,375 | 29,335 | |
| 1944 | R | 15,345 | 15,589 | 30,934 | |
| 1940 | D | 18,456 | 14,804 | 33,448 | |
| 1936 | D | 19,721 | 11,191 | 31,203 | |
| 1932 | R | 12,033 | 12,911 | 26,322 | |
| 1928 | R | 9,026 | 19,443 | 28,703 | |
| 1924 | R | 4,442 | 9,042 | 16,370 | |
| 1920 | R | 5,643 | 9,595 | 16,725 | |
| 1916 | R | 4,859 | 5,760 | 11,172 | |
| 1912 | D | 10,593 | 1,396 | 8,593 | |
| 1908 | D | 9,289 | 4,791 | 624 | |
| 1904 | D | 10,880 | 5,232 | 731 | |
| 1900 | R | 4,527 | 5,944 | 126 | |
| 1896 | R | 3,907 | 5,464 | 9,680 | |
| 1892 | R | 3,638 | 4,415 | 8,312 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Anchored by Cumberland in the Appalachian Ridge and Valley region, Allegany County has shifted steadily rightward over two decades, recording an R+40.2 presidential margin in 2024 — among the widest in a state that Democrats carried by double digits.
The Democratic margin in Allegany County peaked at 100 points in 1904. By 1980 the county had flipped, voting Republican for the first time in many years. The 2024 margin was forty points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Allegany County's median household income of $59,603 sits well below state and national norms, and 17% 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 Moniteau County and Whitley County.