| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 2,175 | 10,524 | 12,806 | |
| 2020 | R | 2,337 | 10,161 | 12,640 | |
| 2016 | R | 2,038 | 8,059 | 10,343 | |
| 2012 | R | 2,410 | 7,107 | 9,616 | |
| 2008 | R | 2,721 | 6,151 | 8,958 | |
| 2004 | R | 2,688 | 5,394 | 8,125 | |
| 2000 | R | 2,946 | 4,623 | 7,714 | |
| 1996 | R | 2,771 | 2,878 | 6,485 | |
| 1992 | D | 2,846 | 2,494 | 7,011 | |
| 1988 | D | 2,972 | 2,691 | 5,688 | |
| 1984 | R | 2,466 | 3,174 | 5,659 | |
| 1980 | D | 2,376 | 1,726 | 4,193 | |
| 1976 | D | 2,406 | 1,094 | 3,529 | |
| 1972 | R | 1,020 | 1,296 | 2,322 | |
| 1968 | D | 1,235 | 381 | 2,309 | |
| 1964 | D | 1,680 | 343 | 2,026 | |
| 1960 | D | 1,115 | 448 | 1,570 | |
| 1956 | D | 755 | 565 | 1,329 | |
| 1952 | D | 1,043 | 494 | 1,541 | |
| 1948 | D | 509 | 106 | 774 | |
| 1944 | D | 522 | 53 | 720 | |
| 1940 | D | 764 | 119 | 884 | |
| 1936 | D | 564 | 67 | 631 | |
| 1932 | D | 828 | 16 | 848 | |
| 1928 | D | 503 | 296 | 800 | |
| 1924 | D | 585 | 104 | 700 | |
| 1920 | D | 320 | 7 | 691 | |
| 1916 | D | 442 | 255 | 699 | |
| 1912 | D | 377 | 176 | 645 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
San Jacinto County, a heavily forested area northeast of Houston, recorded an R+65.3 presidential margin in 2024—among the widest in the state—reflecting the deep-red realignment that has reshaped small, rural Texas counties over the past two decades.
The unraveling was not abrupt. The Democratic margin in San Jacinto County peaked at ninety-six 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 two points. By 2024, the margin had widened further.
The economic and demographic context is severe. San Jacinto County's median household income of $65,364 is among the lowest of any county in the United States; 18% of residents live below the federal poverty line. The county's voting pattern over the last decade is most similar to that of Polk County and Rains County.