| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 152 | 1,285 | 1,447 | |
| 2020 | R | 197 | 1,389 | 1,609 | |
| 2016 | R | 222 | 1,261 | 1,544 | |
| 2012 | R | 253 | 1,248 | 1,534 | |
| 2008 | R | 302 | 1,269 | 1,589 | |
| 2004 | R | 305 | 1,473 | 1,782 | |
| 2000 | R | 341 | 1,385 | 1,744 | |
| 1996 | R | 483 | 970 | 1,634 | |
| 1992 | R | 434 | 922 | 1,683 | |
| 1988 | R | 645 | 1,205 | 1,862 | |
| 1984 | R | 496 | 1,594 | 2,103 | |
| 1980 | R | 632 | 965 | 1,639 | |
| 1976 | D | 1,029 | 936 | 2,007 | |
| 1972 | R | 327 | 1,271 | 1,629 | |
| 1968 | R | 588 | 990 | 2,008 | |
| 1964 | D | 1,058 | 700 | 1,759 | |
| 1960 | R | 835 | 961 | 1,808 | |
| 1956 | D | 1,074 | 1,018 | 2,103 | |
| 1952 | R | 1,197 | 1,464 | 2,673 | |
| 1948 | D | 1,504 | 399 | 1,943 | |
| 1944 | D | 1,118 | 323 | 1,610 | |
| 1940 | D | 1,539 | 427 | 1,974 | |
| 1936 | D | 1,436 | 220 | 1,727 | |
| 1932 | D | 1,935 | 341 | 2,300 | |
| 1928 | R | 539 | 618 | 1,166 | |
| 1924 | D | 506 | 254 | 1,045 | |
| 1920 | D | 478 | 195 | 736 | |
| 1916 | D | 363 | 81 | 490 | |
| 1912 | D | 247 | 18 | 403 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Dallam County, anchored by the feedlot and farming hub of Dalhart, recorded an R+78.3 margin in 2024 — among the widest in the state — reflecting the heavily rural, agricultural character of the Texas Panhandle's western edge.
The unraveling was not abrupt. The Democratic margin in Dallam County peaked at seventy points in 1936; it narrowed steadily over the late twentieth century. The 1980 election delivered the county to the Republican party for the first time in many years, by a margin of twenty points. By 2024, the margin had widened further.
The economic and demographic context is severe. Dallam County's median household income of $71,500 is among the lowest of any county in the United States; 12% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Cheyenne County and Lincoln County.