| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | R | 3,840 | 9,349 | 13,510 | |
| 2020 | R | 3,837 | 8,958 | 13,161 | |
| 2016 | R | 3,174 | 7,764 | 11,669 | |
| 2012 | R | 4,588 | 6,696 | 11,524 | |
| 2008 | R | 5,595 | 6,374 | 12,185 | |
| 2004 | R | 4,803 | 7,778 | 12,751 | |
| 2000 | D | 6,718 | 4,192 | 11,138 | |
| 1996 | R | 4,722 | 4,995 | 11,055 | |
| 1992 | R | 3,701 | 3,943 | 10,943 | |
| 1988 | R | 4,570 | 5,050 | 9,714 | |
| 1984 | R | 3,528 | 6,108 | 9,678 | |
| 1980 | R | 3,353 | 5,903 | 9,990 | |
| 1976 | D | 4,680 | 4,504 | 9,213 | |
| 1972 | R | 4,601 | 4,936 | 9,564 | |
| 1968 | D | 4,235 | 3,929 | 8,452 | |
| 1964 | D | 5,353 | 3,593 | 8,946 | |
| 1960 | R | 4,304 | 5,309 | 9,613 | |
| 1956 | R | 3,772 | 5,150 | 8,922 | |
| 1952 | R | 2,974 | 5,750 | 8,724 | |
| 1948 | D | 4,042 | 3,349 | 7,441 | |
| 1944 | R | 3,120 | 3,348 | 6,468 | |
| 1940 | R | 3,705 | 4,320 | 8,025 | |
| 1936 | D | 4,256 | 3,005 | 7,620 | |
| 1932 | D | 4,806 | 2,538 | 7,396 | |
| 1928 | R | 3,299 | 3,762 | 7,087 | |
| 1924 | R | 627 | 1,862 | 4,500 | |
| 1920 | R | 867 | 2,706 | 4,522 | |
| 1916 | D | 1,550 | 1,344 | 2,991 | |
| 1912 | D | 1,111 | 0 | 2,467 | |
| 1908 | R | 831 | 1,618 | 2,556 | |
| 1904 | R | 582 | 1,741 | 2,412 | |
| 1900 | R | 805 | 1,225 | 2,102 | |
| 1896 | R | 759 | 1,041 | 1,823 | |
| 1892 | R | 408 | 882 | 1,691 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Codington County anchors South Dakota's northeastern lake district, and its small-city core of Watertown hasn't softened a Republican lean that has held above 40 points in recent presidential cycles.
The Republican margin in Codington County reached its widest at forty-eight points in 1904. The margin in 2024 was forty-one points, in line with the county's deep historical pattern.
Codington County's loyalty is rooted in its place. Median household income of $72,727, a 91% non-Hispanic-white share, and a population of 28,767 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 Yankton County and Clark County.
