| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 6,862 | 9,487 | 16,431 | |
| 2020 | D | 9,123 | 8,247 | 17,525 | |
| 2016 | D | 9,289 | 2,224 | 11,740 | |
| 2012 | D | 10,260 | 1,547 | 11,883 | |
| 2008 | D | 8,274 | 1,492 | 9,792 | |
| 2004 | D | 7,199 | 2,552 | 9,781 | |
| 2000 | D | 6,505 | 1,911 | 8,464 | |
| 1996 | D | 6,312 | 756 | 7,260 | |
| 1992 | D | 7,668 | 1,209 | 9,261 | |
| 1988 | D | 6,958 | 1,218 | 8,211 | |
| 1984 | D | 5,047 | 1,658 | 6,713 | |
| 1980 | D | 4,782 | 1,389 | 6,253 | |
| 1976 | D | 4,646 | 664 | 5,325 | |
| 1972 | D | 3,320 | 2,389 | 5,713 | |
| 1968 | D | 3,922 | 1,374 | 5,367 | |
| 1964 | D | 4,056 | 678 | 4,742 | |
| 1960 | D | 4,051 | 280 | 4,333 | |
| 1956 | D | 2,727 | 547 | 3,274 | |
| 1952 | D | 3,055 | 620 | 3,675 | |
| 1948 | D | 1,996 | 179 | 2,188 | |
| 1944 | D | 1,312 | 68 | 1,395 | |
| 1940 | D | 1,200 | 68 | 1,268 | |
| 1936 | D | 2,289 | 320 | 2,618 | |
| 1932 | D | 754 | 32 | 786 | |
| 1928 | D | 736 | 79 | 815 | |
| 1924 | D | 756 | 23 | 779 | |
| 1920 | D | 418 | 89 | 507 | |
| 1916 | D | 516 | 115 | 631 | |
| 1912 | D | 674 | 252 | 928 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Starr County, once among the most reliably Democratic counties in Texas, shifted to R+16 in 2024 — a dramatic realignment in a majority-Hispanic, rural border community where economic concerns increasingly override historical party loyalty.
The Democratic margin in Starr County peaked at ninety-four points in 1924. By 2024 the county had flipped, voting Republican for the first time in many years. The 2024 margin was sixteen points, the most Republican-leaning result in the county's modern history.
The economic context is the key. Starr County's median household income of $37,639 sits well below state and national norms, and 34% of residents live below the federal poverty line. The shift here is part of a broader realignment of working-class places across the country. The county's voting pattern over the last decade is most similar to that of Duval County and Brooks County.