| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 6,069 | 6,837 | 13,391 | |
| 2020 | R | 6,604 | 7,035 | 14,130 | |
| 2016 | R | 4,781 | 5,833 | 11,964 | |
| 2012 | R | 5,211 | 5,229 | 10,873 | |
| 2008 | D | 5,906 | 5,103 | 11,380 | |
| 2004 | R | 5,691 | 6,119 | 12,002 | |
| 2000 | R | 4,616 | 5,356 | 10,664 | |
| 1996 | D | 4,967 | 3,662 | 9,952 | |
| 1992 | D | 4,663 | 3,242 | 10,973 | |
| 1988 | D | 5,141 | 4,462 | 9,834 | |
| 1984 | R | 5,526 | 6,905 | 12,472 | |
| 1980 | R | 4,336 | 4,703 | 10,235 | |
| 1976 | D | 4,560 | 4,258 | 9,240 | |
| 1972 | R | 3,749 | 4,537 | 8,775 | |
| 1968 | D | 3,918 | 3,842 | 8,306 | |
| 1964 | D | 5,890 | 2,695 | 8,597 | |
| 1960 | D | 4,426 | 4,355 | 8,784 | |
| 1956 | R | 4,165 | 4,332 | 8,497 | |
| 1952 | R | 2,517 | 4,362 | 6,914 | |
| 1948 | R | 2,438 | 2,740 | 5,296 | |
| 1944 | R | 2,313 | 2,429 | 4,786 | |
| 1940 | D | 3,001 | 2,553 | 5,576 | |
| 1936 | D | 3,573 | 1,278 | 5,184 | |
| 1932 | D | 2,776 | 1,740 | 4,664 | |
| 1928 | R | 1,699 | 2,746 | 4,513 | |
| 1924 | R | 1,185 | 2,409 | 4,681 | |
| 1920 | R | 1,434 | 2,698 | 4,334 | |
| 1916 | D | 2,287 | 2,243 | 4,719 | |
| 1912 | D | 929 | 775 | 2,594 | |
| 1908 | R | 764 | 1,309 | 2,291 | |
| 1904 | R | 536 | 2,092 | 3,107 | |
| 1900 | R | 1,038 | 1,576 | 2,747 | |
| 1896 | R | 1,367 | 1,701 | 3,129 | |
| 1892 | R | 497 | 1,059 | 2,125 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Wasco County straddles the Cascade Range, mixing irrigated-agriculture communities east of the mountains with the more liberal river town of The Dalles, a tension that has compressed its Republican presidential margin to single digits over the past decade.
The Democratic margin in Wasco County has rarely exceeded forty-four points in modern history; the Republican margin has rarely exceeded fifty points. 2024 delivered the county to the Republican candidate by six points.
Wasco County's demographics resemble the country more than they resemble most counties. A 75% non-Hispanic-white share, a 12% poverty rate, and a median household income of $64,175 — all within the broad national range. The county's voting pattern over the last decade is most similar to that of Gates County and Hill County.