| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 4,058 | 14,020 | 18,265 | |
| 2020 | R | 4,261 | 12,959 | 17,449 | |
| 2016 | R | 3,382 | 10,945 | 14,832 | |
| 2012 | R | 3,381 | 10,857 | 14,397 | |
| 2008 | R | 4,034 | 10,176 | 14,377 | |
| 2004 | R | 3,389 | 9,597 | 13,063 | |
| 2000 | R | 2,996 | 8,645 | 11,809 | |
| 1996 | R | 3,460 | 6,319 | 10,419 | |
| 1992 | R | 3,283 | 5,817 | 10,853 | |
| 1988 | R | 2,960 | 6,041 | 9,037 | |
| 1984 | R | 2,483 | 6,506 | 8,996 | |
| 1980 | R | 2,518 | 4,821 | 7,495 | |
| 1976 | R | 2,635 | 3,820 | 6,500 | |
| 1972 | R | 1,323 | 3,862 | 5,198 | |
| 1968 | R | 1,686 | 3,244 | 5,607 | |
| 1964 | D | 2,938 | 2,019 | 4,962 | |
| 1960 | R | 1,864 | 2,613 | 4,489 | |
| 1956 | R | 933 | 2,975 | 3,923 | |
| 1952 | R | 1,354 | 3,519 | 4,876 | |
| 1948 | R | 1,647 | 1,904 | 3,742 | |
| 1944 | D | 1,387 | 534 | 4,025 | |
| 1940 | R | 1,449 | 1,868 | 3,317 | |
| 1936 | D | 1,993 | 176 | 2,173 | |
| 1932 | D | 3,443 | 99 | 3,545 | |
| 1928 | D | 2,491 | 275 | 2,766 | |
| 1924 | D | 3,568 | 496 | 4,137 | |
| 1920 | D | 796 | 684 | 3,220 | |
| 1916 | R | 1,119 | 1,306 | 2,431 | |
| 1912 | D | 1,111 | 546 | 1,855 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Washington County, home to the historic town of Brenham, posts some of the widest Republican presidential margins in the Brazos Valley region, with ranching and small-town demographics anchoring a consistently lopsided electorate.
The Republican margin in Washington County reached its widest at fifty-five points in 2024. The margin in 2024 was fifty-five points, in line with the county's deep historical pattern.
Washington County's loyalty is rooted in its place. Median household income of $77,825, a 67% non-Hispanic-white share, and a population of 36,647 together describe a community whose political habits are deeply settled. The county's voting pattern over the last decade is most similar to that of Grant County and Brown County.
