| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 65,528 | 58,438 | 125,827 | |
| 2020 | D | 59,524 | 47,680 | 109,395 | |
| 2016 | R | 33,224 | 33,826 | 72,164 | |
| 2012 | R | 25,537 | 31,661 | 59,011 | |
| 2008 | R | 28,431 | 29,638 | 59,052 | |
| 2004 | R | 20,110 | 27,021 | 47,823 | |
| 2000 | R | 11,387 | 20,170 | 34,317 | |
| 1996 | R | 11,580 | 12,865 | 26,840 | |
| 1992 | D | 10,842 | 10,008 | 27,267 | |
| 1988 | R | 11,187 | 11,716 | 23,264 | |
| 1984 | R | 6,663 | 12,467 | 19,187 | |
| 1980 | R | 6,013 | 6,517 | 13,289 | |
| 1976 | D | 7,005 | 5,714 | 12,875 | |
| 1972 | R | 4,068 | 5,406 | 9,519 | |
| 1968 | D | 3,546 | 1,993 | 6,183 | |
| 1964 | D | 3,780 | 1,279 | 5,064 | |
| 1960 | D | 2,916 | 1,606 | 4,529 | |
| 1956 | D | 2,017 | 1,873 | 3,904 | |
| 1952 | R | 2,070 | 2,135 | 4,208 | |
| 1948 | D | 2,239 | 555 | 2,987 | |
| 1944 | D | 1,690 | 495 | 2,428 | |
| 1940 | D | 2,371 | 453 | 2,828 | |
| 1936 | D | 1,964 | 286 | 2,259 | |
| 1932 | D | 1,822 | 220 | 2,050 | |
| 1928 | R | 620 | 1,088 | 1,708 | |
| 1924 | D | 1,616 | 394 | 2,089 | |
| 1920 | D | 1,075 | 242 | 1,656 | |
| 1916 | D | 995 | 123 | 1,133 | |
| 1912 | D | 939 | 60 | 1,065 | |
| 1908 | — | — | — | — | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Hays County has nearly doubled in population since 2010 as Austin's sprawl pushes south, and that demographic churn pushed the 2024 presidential margin to D+5.6 — a notable shift in a county that leaned Republican as recently as 2016.
The Democratic margin in Hays County has rarely exceeded eighty-three points in modern history; the Republican margin has rarely exceeded thirty points. 2024 delivered the county to the Democratic candidate by six points.
Hays County's demographics resemble the country more than they resemble most counties. A 61% non-Hispanic-white share, a 12% poverty rate, and a median household income of $89,097 — all within the broad national range. The county's voting pattern over the last decade is most similar to that of Deschutes County and Haines Borough.
