| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 55,215 | 53,585 | 110,824 | |
| 2020 | D | 59,896 | 53,164 | 115,238 | |
| 2016 | D | 52,247 | 52,019 | 111,835 | |
| 2012 | D | 56,460 | 52,578 | 111,009 | |
| 2008 | D | 68,710 | 48,510 | 118,389 | |
| 2004 | R | 52,637 | 55,254 | 108,619 | |
| 2000 | D | 47,703 | 47,581 | 97,474 | |
| 1996 | D | 45,704 | 38,281 | 93,188 | |
| 1992 | D | 46,203 | 38,934 | 104,465 | |
| 1988 | R | 48,056 | 49,481 | 97,864 | |
| 1984 | R | 47,513 | 54,404 | 102,493 | |
| 1980 | R | 44,218 | 50,607 | 103,114 | |
| 1976 | R | 49,156 | 50,358 | 100,324 | |
| 1972 | R | 41,629 | 64,808 | 107,039 | |
| 1968 | D | 47,414 | 47,114 | 106,864 | |
| 1964 | D | 65,844 | 39,872 | 106,346 | |
| 1960 | D | 63,553 | 53,621 | 117,499 | |
| 1956 | R | 54,152 | 57,827 | 112,472 | |
| 1952 | R | 53,269 | 53,537 | 107,632 | |
| 1948 | D | 49,866 | 39,593 | 90,846 | |
| 1944 | D | 47,149 | 39,875 | 87,589 | |
| 1940 | D | 45,620 | 36,164 | 82,158 | |
| 1936 | D | 43,131 | 25,807 | 70,339 | |
| 1932 | D | 38,026 | 28,198 | 68,563 | |
| 1928 | R | 26,846 | 36,844 | 64,006 | |
| 1924 | R | 15,056 | 23,682 | 41,082 | |
| 1920 | R | 12,355 | 17,675 | 31,305 | |
| 1916 | D | 9,709 | 7,961 | 18,505 | |
| 1912 | D | 5,391 | 3,146 | 15,601 | |
| 1908 | R | 8,562 | 11,222 | 20,813 | |
| 1904 | R | 5,967 | 11,166 | 17,854 | |
| 1900 | R | 6,948 | 8,127 | 15,305 | |
| 1896 | R | 6,247 | 7,138 | 13,521 | |
| 1892 | D | 6,077 | 5,220 | 11,619 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Home to South Bend and the University of Notre Dame, St. Joseph County has trended competitive over the last decade, with its 2024 presidential margin landing within 1.5 points — unusually close for a county anchored by a major research university.
The county's recent history is a story of close margins. The Democratic margin reached twenty-five points in 1936; the Republican margin reached twenty-nine points in 1904. Most other elections have been decided by single-digit points.
St. Joseph County's demographics — a population of 273,040, a 71% non-Hispanic-white share, a median household income of $66,868 — situate the county close to national averages on several dimensions. The county's voting pattern over the last decade is most similar to that of Peoria County and Sandoval County.
