| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 1,765 | 1,653 | 3,427 | |
| 2020 | D | 2,264 | 1,384 | 3,666 | |
| 2016 | D | 2,173 | 974 | 3,225 | |
| 2012 | D | 2,141 | 762 | 2,917 | |
| 2008 | D | 2,692 | 874 | 3,587 | |
| 2004 | D | 2,365 | 1,188 | 3,566 | |
| 2000 | D | 2,678 | 1,032 | 3,753 | |
| 1996 | D | 2,242 | 604 | 2,991 | |
| 1992 | D | 3,172 | 844 | 4,380 | |
| 1988 | D | 2,735 | 900 | 3,651 | |
| 1984 | D | 2,546 | 1,338 | 3,892 | |
| 1980 | D | 2,102 | 1,173 | 3,323 | |
| 1976 | D | 1,721 | 890 | 2,624 | |
| 1972 | R | 1,078 | 1,172 | 2,262 | |
| 1968 | D | 896 | 584 | 1,660 | |
| 1964 | D | 1,184 | 501 | 1,688 | |
| 1960 | D | 886 | 648 | 1,537 | |
| 1956 | R | 427 | 705 | 1,139 | |
| 1952 | R | 503 | 954 | 1,460 | |
| 1948 | D | 863 | 384 | 1,318 | |
| 1944 | D | 554 | 328 | 977 | |
| 1940 | D | 736 | 340 | 1,079 | |
| 1936 | D | 704 | 296 | 1,021 | |
| 1932 | D | 843 | 241 | 1,090 | |
| 1928 | R | 258 | 626 | 884 | |
| 1924 | D | 289 | 180 | 493 | |
| 1920 | D | 231 | 108 | 343 | |
| 1916 | D | 193 | 74 | 268 | |
| 1912 | D | 292 | 131 | 481 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Dimmit County, anchored by Carrizo Springs and stretching across the Eagle Ford Shale formation, shifted from D+32 in 2020 to D+3.3 in 2024, a swing that tracks a broader realignment among predominantly Hispanic border communities.
The unraveling was not abrupt. The Democratic margin in Dimmit County peaked at fifty-five points in 1932; it narrowed steadily over the late twentieth century. The 1976 election delivered the county to the Republican party for the first time in many years, by a margin of thirty-two points. By 2024, the margin had settled into deep Republican territory.
The economic and demographic context is severe. Dimmit County's median household income of $38,808 is among the lowest of any county in the United States; 41% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Zavala County and Charles City County.