| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 27,260 | 44,054 | 73,332 | |
| 2020 | R | 26,044 | 40,224 | 67,779 | |
| 2016 | R | 21,129 | 40,998 | 65,071 | |
| 2012 | R | 25,042 | 36,074 | 62,755 | |
| 2008 | R | 26,245 | 34,169 | 61,600 | |
| 2004 | R | 20,387 | 36,917 | 57,904 | |
| 2000 | R | 18,221 | 27,948 | 47,470 | |
| 1996 | R | 16,481 | 21,434 | 42,142 | |
| 1992 | R | 16,495 | 21,977 | 46,208 | |
| 1988 | R | 14,408 | 25,912 | 40,638 | |
| 1984 | R | 13,329 | 27,118 | 40,666 | |
| 1980 | R | 14,118 | 22,901 | 39,083 | |
| 1976 | R | 15,902 | 20,194 | 36,096 | |
| 1972 | R | 10,039 | 24,234 | 34,985 | |
| 1968 | R | 11,266 | 16,050 | 34,053 | |
| 1964 | D | 19,858 | 12,756 | 32,614 | |
| 1960 | R | 15,632 | 17,828 | 33,460 | |
| 1956 | R | 11,562 | 19,455 | 31,017 | |
| 1952 | R | 12,657 | 17,653 | 30,394 | |
| 1948 | R | 10,588 | 11,887 | 22,630 | |
| 1944 | R | 11,365 | 12,227 | 23,592 | |
| 1940 | D | 14,125 | 11,054 | 25,262 | |
| 1936 | D | 14,050 | 10,619 | 24,718 | |
| 1932 | D | 11,370 | 8,929 | 20,527 | |
| 1928 | R | 5,816 | 12,404 | 18,301 | |
| 1924 | R | 4,620 | 7,460 | 13,762 | |
| 1920 | R | 6,852 | 8,757 | 15,995 | |
| 1916 | D | 5,642 | 5,093 | 11,100 | |
| 1912 | D | 9,377 | 1,907 | 9,540 | |
| 1908 | D | 8,833 | 4,518 | 209 | |
| 1904 | D | 10,520 | 4,581 | 188 | |
| 1900 | R | 4,862 | 5,475 | 29 | |
| 1896 | R | 4,382 | 5,428 | 10,133 | |
| 1892 | D | 4,667 | 4,373 | 9,273 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Washington County anchors Maryland's westernmost settled corridor, where rural and small-city voters have backed Republican presidential candidates by double-digit margins in every cycle since 2000, reaching a 22.9-point spread in 2024.
The Democratic margin in Washington County peaked at 100 points in 1904. By 1968 the county had flipped, voting Republican for the first time in many years. The 2024 margin was twenty-three points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Washington County's median household income of $77,747 sits well below state and national norms, and 12% 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 York County and Montour County.