| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 3,506 | 2,314 | 5,997 | |
| 2020 | D | 3,992 | 1,979 | 6,087 | |
| 2016 | D | 3,204 | 1,733 | 5,232 | |
| 2012 | D | 2,879 | 1,699 | 4,656 | |
| 2008 | D | 2,463 | 1,634 | 4,140 | |
| 2004 | R | 1,498 | 1,807 | 3,332 | |
| 2000 | R | 1,048 | 1,460 | 2,580 | |
| 1996 | R | 748 | 916 | 1,838 | |
| 1992 | R | 567 | 792 | 1,720 | |
| 1988 | R | 434 | 993 | 1,446 | |
| 1984 | R | 375 | 975 | 1,355 | |
| 1980 | R | 447 | 729 | 1,254 | |
| 1976 | D | 709 | 444 | 1,189 | |
| 1972 | R | 4,208 | 13,259 | 17,890 | |
| 1968 | — | — | — | — | |
| 1964 | — | — | — | — | |
| 1960 | — | — | — | — | |
| 1956 | — | — | — | — | |
| 1952 | — | — | — | — | |
| 1948 | — | — | — | — | |
| 1944 | — | — | — | — | |
| 1940 | — | — | — | — | |
| 1936 | — | — | — | — | |
| 1932 | — | — | — | — | |
| 1928 | — | — | — | — | |
| 1924 | — | — | — | — | |
| 1920 | — | — | — | — | |
| 1916 | — | — | — | — | |
| 1912 | — | — | — | — | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Manassas Park is an enclave of roughly 10,000 residents entirely surrounded by Prince William County, and its dense, majority-minority population has produced consistent double-digit Democratic margins in recent presidential cycles.
The 2008 election was the turning point, when the Democratic candidate carried the county by twenty points. The 2024 margin was twenty points, in line with the county's new direction.
The demographics suggest why. A population of 16,798, a 33% non-Hispanic-white share, and a median household income of $103,250 situate the county in the broader realignment patterns of recent cycles. The county's voting pattern over the last decade is most similar to that of Prince William County and Danville city.
