| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 1,973 | 6,447 | 8,523 | |
| 2020 | R | 1,911 | 5,443 | 7,459 | |
| 2016 | R | 1,244 | 4,212 | 5,685 | |
| 2012 | R | 1,220 | 3,638 | 4,973 | |
| 2008 | R | 1,467 | 3,418 | 4,939 | |
| 2004 | R | 1,267 | 3,277 | 4,584 | |
| 2000 | R | 811 | 2,777 | 3,767 | |
| 1996 | R | 1,028 | 1,919 | 3,316 | |
| 1992 | R | 891 | 1,370 | 3,109 | |
| 1988 | R | 1,012 | 1,680 | 2,719 | |
| 1984 | R | 700 | 1,957 | 2,665 | |
| 1980 | R | 794 | 1,434 | 2,301 | |
| 1976 | R | 923 | 1,015 | 1,956 | |
| 1972 | R | 460 | 1,215 | 1,695 | |
| 1968 | D | 620 | 614 | 1,457 | |
| 1964 | D | 1,197 | 290 | 1,488 | |
| 1960 | D | 830 | 557 | 1,394 | |
| 1956 | R | 615 | 796 | 1,418 | |
| 1952 | R | 697 | 919 | 1,618 | |
| 1948 | D | 1,003 | 497 | 1,569 | |
| 1944 | D | 846 | 533 | 1,512 | |
| 1940 | D | 1,042 | 520 | 1,567 | |
| 1936 | D | 1,056 | 313 | 1,372 | |
| 1932 | D | 1,233 | 127 | 1,367 | |
| 1928 | R | 539 | 615 | 1,155 | |
| 1924 | D | 586 | 317 | 1,078 | |
| 1920 | D | 426 | 378 | 1,708 | |
| 1916 | D | 628 | 235 | 885 | |
| 1912 | D | 448 | 126 | 667 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Blanco County's sparse population and deep ranching roots make it one of the more reliably conservative counties in the Texas Hill Country, with presidential margins that have held above R+50 for over a decade.
The unraveling was not abrupt. The Democratic margin in Blanco County peaked at eighty-one points in 1932; it narrowed steadily over the late twentieth century. The 1972 election delivered the county to the Republican party for the first time in many years, by a margin of forty-five points. By 2024, the margin had widened further.
The economic and demographic context is severe. Blanco County's median household income of $92,425 is among the lowest of any county in the United States; 8% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Powder River County and Petroleum County.