| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 10,183 | 17,077 | 27,561 | |
| 2020 | R | 8,191 | 14,260 | 22,734 | |
| 2016 | R | 5,748 | 10,531 | 16,784 | |
| 2012 | R | 6,514 | 9,244 | 15,902 | |
| 2008 | R | 7,153 | 8,265 | 15,508 | |
| 2004 | R | 6,145 | 7,679 | 13,881 | |
| 2000 | R | 5,046 | 5,686 | 10,858 | |
| 1996 | D | 4,535 | 3,559 | 8,622 | |
| 1992 | D | 4,270 | 3,065 | 9,058 | |
| 1988 | D | 3,957 | 3,607 | 7,624 | |
| 1984 | R | 3,828 | 4,116 | 7,963 | |
| 1980 | D | 3,329 | 3,019 | 6,463 | |
| 1976 | D | 2,828 | 1,992 | 4,862 | |
| 1972 | R | 1,538 | 2,263 | 3,839 | |
| 1968 | D | 1,684 | 958 | 3,439 | |
| 1964 | D | 2,167 | 980 | 3,149 | |
| 1960 | R | 1,101 | 1,115 | 2,267 | |
| 1956 | R | 929 | 1,426 | 2,397 | |
| 1952 | R | 1,264 | 1,487 | 2,753 | |
| 1948 | D | 812 | 448 | 1,634 | |
| 1944 | D | 1,007 | 190 | 1,436 | |
| 1940 | D | 1,065 | 300 | 1,366 | |
| 1936 | D | 889 | 111 | 1,002 | |
| 1932 | D | 1,192 | 89 | 1,283 | |
| 1928 | D | 504 | 376 | 881 | |
| 1924 | D | 1,239 | 203 | 1,461 | |
| 1920 | D | 674 | 167 | 1,250 | |
| 1916 | D | 636 | 182 | 826 | |
| 1912 | D | 594 | 144 | 858 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Waller County sits on Houston's northwestern fringe, where rapid residential development has not yet shifted its presidential margins, which held at R+25 in 2024 despite population growth exceeding many neighboring counties.
The shift began with civil rights. 2000 marked the realignment in Waller County, by a six points margin. The Republican margin reached its widest at twenty-eight points in 2016. The 2024 margin was twenty-five points.
The political shift has tracked, in Waller County, the political shift of the South more broadly. A 45% non-Hispanic-white share, a median household income of $80,397, and a 15% poverty rate describe the demographic context. The county's voting pattern over the last decade is most similar to that of Saline County and Marshall County.