| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 9,064 | 27,302 | 37,371 | |
| 2020 | R | 9,391 | 25,897 | 36,501 | |
| 2016 | R | 6,233 | 19,828 | 29,873 | |
| 2012 | R | 7,541 | 19,773 | 28,142 | |
| 2008 | R | 8,621 | 19,032 | 28,344 | |
| 2004 | R | 6,458 | 19,672 | 26,435 | |
| 2000 | R | 5,777 | 15,794 | 22,530 | |
| 1996 | R | 6,826 | 12,393 | 22,896 | |
| 1992 | R | 6,593 | 10,335 | 23,503 | |
| 1988 | R | 7,078 | 13,243 | 20,734 | |
| 1984 | R | 4,567 | 16,974 | 21,771 | |
| 1980 | R | 4,835 | 17,425 | 23,708 | |
| 1976 | R | 6,085 | 12,659 | 19,233 | |
| 1972 | R | 3,344 | 13,075 | 17,673 | |
| 1968 | R | 4,001 | 11,564 | 18,373 | |
| 1964 | R | 7,638 | 11,518 | 19,156 | |
| 1960 | R | 7,413 | 12,171 | 19,584 | |
| 1956 | R | 5,666 | 12,097 | 17,763 | |
| 1952 | R | 4,548 | 14,471 | 19,023 | |
| 1948 | R | 6,019 | 7,833 | 14,061 | |
| 1944 | R | 6,128 | 7,946 | 14,116 | |
| 1940 | R | 7,286 | 9,031 | 16,351 | |
| 1936 | D | 7,476 | 4,966 | 12,828 | |
| 1932 | D | 6,395 | 4,928 | 11,719 | |
| 1928 | R | 2,471 | 6,791 | 9,338 | |
| 1924 | R | 1,641 | 4,630 | 9,071 | |
| 1920 | R | 2,882 | 5,894 | 8,776 | |
| 1916 | D | 3,974 | 3,083 | 7,701 | |
| 1912 | D | 1,741 | 1,074 | 5,348 | |
| 1908 | R | 1,053 | 1,757 | 3,162 | |
| 1904 | — | — | — | — | |
| 1900 | — | — | — | — | |
| 1896 | — | — | — | — | |
| 1892 | — | — | — | — | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Twin Falls County sits in the Snake River Plain and has voted Republican by margins exceeding 40 points in recent cycles, with its mid-sized urban core not meaningfully softening that partisan lean.
The Republican margin in Twin Falls County reached its widest at fifty-seven points in 1984. The margin in 2024 was forty-nine points, in line with the county's deep historical pattern.
Twin Falls County's loyalty is rooted in its place. Median household income of $67,409, a 79% non-Hispanic-white share, and a population of 93,734 together describe a community whose political habits are deeply settled. The county's voting pattern over the last decade is most similar to that of Jerome County and Klamath County.
