| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 310 | 2,418 | 2,742 | |
| 2020 | R | 271 | 2,217 | 2,505 | |
| 2016 | R | 243 | 1,951 | 2,245 | |
| 2012 | R | 279 | 1,882 | 2,201 | |
| 2008 | R | 398 | 1,753 | 2,177 | |
| 2004 | R | 416 | 1,794 | 2,231 | |
| 2000 | R | 548 | 1,738 | 2,314 | |
| 1996 | R | 748 | 1,044 | 2,033 | |
| 1992 | D | 753 | 702 | 1,990 | |
| 1988 | R | 842 | 1,043 | 1,888 | |
| 1984 | R | 688 | 1,262 | 1,960 | |
| 1980 | D | 1,028 | 985 | 2,059 | |
| 1976 | D | 1,012 | 684 | 1,710 | |
| 1972 | R | 388 | 1,089 | 1,483 | |
| 1968 | D | 722 | 645 | 1,663 | |
| 1964 | D | 1,228 | 495 | 1,723 | |
| 1960 | R | 869 | 1,012 | 1,887 | |
| 1956 | R | 735 | 912 | 1,648 | |
| 1952 | R | 875 | 1,089 | 1,966 | |
| 1948 | D | 1,135 | 205 | 1,418 | |
| 1944 | D | 1,428 | 172 | 1,817 | |
| 1940 | D | 1,658 | 287 | 1,946 | |
| 1936 | D | 1,005 | 165 | 1,170 | |
| 1932 | D | 1,434 | 133 | 1,567 | |
| 1928 | R | 442 | 774 | 1,216 | |
| 1924 | D | 1,289 | 175 | 1,515 | |
| 1920 | D | 669 | 247 | 1,201 | |
| 1916 | D | 640 | 129 | 878 | |
| 1912 | D | 573 | 92 | 917 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Mills County's sparse Hill Country ranching economy and population under 6,000 produce some of the state's widest presidential margins, with the 2024 result landing nearly 77 points to the right of the national median.
The unraveling was not abrupt. The Democratic margin in Mills County peaked at eighty-three points in 1932; it narrowed steadily over the late twentieth century. The 1996 election delivered the county to the Republican party for the first time in many years, by a margin of fifteen points. By 2024, the margin had widened further.
The economic and demographic context is severe. Mills County's median household income of $67,620 is among the lowest of any county in the United States; 7% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Coleman County and Coke County.