| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 4,735 | 17,184 | 22,120 | |
| 2020 | R | 4,603 | 16,670 | 21,502 | |
| 2016 | R | 3,877 | 14,094 | 18,721 | |
| 2012 | R | 4,273 | 11,939 | 16,416 | |
| 2008 | R | 5,375 | 10,929 | 16,502 | |
| 2004 | R | 4,889 | 11,726 | 16,802 | |
| 2000 | R | 4,835 | 9,400 | 14,614 | |
| 1996 | R | 5,327 | 6,888 | 13,718 | |
| 1992 | R | 4,946 | 6,300 | 14,688 | |
| 1988 | R | 4,790 | 8,170 | 13,075 | |
| 1984 | R | 5,178 | 9,106 | 14,373 | |
| 1980 | R | 5,226 | 7,541 | 13,520 | |
| 1976 | R | 6,210 | 7,698 | 14,109 | |
| 1972 | R | 3,667 | 9,989 | 13,855 | |
| 1968 | R | 5,681 | 8,133 | 14,698 | |
| 1964 | D | 8,811 | 6,006 | 14,856 | |
| 1960 | R | 4,816 | 10,315 | 15,203 | |
| 1956 | R | 5,078 | 8,638 | 13,725 | |
| 1952 | R | 5,889 | 8,620 | 14,556 | |
| 1948 | R | 4,762 | 5,666 | 10,523 | |
| 1944 | R | 5,693 | 6,205 | 11,952 | |
| 1940 | D | 6,993 | 6,352 | 13,379 | |
| 1936 | D | 9,581 | 6,867 | 16,525 | |
| 1932 | R | 3,654 | 5,525 | 9,372 | |
| 1928 | R | 1,270 | 8,932 | 10,270 | |
| 1924 | R | 1,999 | 4,780 | 7,143 | |
| 1920 | R | 2,400 | 3,872 | 6,571 | |
| 1916 | R | 1,965 | 2,105 | 4,444 | |
| 1912 | D | 1,400 | 654 | 4,480 | |
| 1908 | R | 1,799 | 2,902 | 4,886 | |
| 1904 | R | 1,378 | 3,054 | 4,620 | |
| 1900 | R | 1,842 | 2,594 | 4,593 | |
| 1896 | R | 2,052 | 2,662 | 4,910 | |
| 1892 | R | 2,029 | 2,175 | 4,366 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Mifflin County, anchored by Lewistown in the Juniata River valley, delivered a 56-point Republican margin in 2024—among the widest in a state notorious for its sharp rural-urban divide.
The Democratic margin in Mifflin County peaked at nineteen points in 1964. By 1968 the county had flipped, voting Republican for the first time in many years. The 2024 margin was fifty-six points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Mifflin County's median household income of $63,953 sits well below state and national norms, and 16% 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 Taney County and Osage County.