2024 results by precinct
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Margin—
Turnout—
Harris +50Trump +50
Real precinct boundaries. Hover for vote totals.
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| 2024 | D | 63,433 | 54,021 | 119,962 | |
| 2020 | D | 68,325 | 57,150 | 129,405 | |
| 2016 | D | 60,756 | 53,857 | 121,436 | |
| 2012 | D | 67,285 | 50,125 | 119,827 | |
| 2008 | D | 76,160 | 47,958 | 125,744 | |
| 2004 | D | 62,410 | 50,203 | 113,189 | |
| 2000 | D | 55,961 | 42,299 | 100,393 | |
| 1996 | D | 53,405 | 33,066 | 94,429 | |
| 1992 | D | 57,625 | 31,951 | 107,541 | |
| 1988 | D | 55,465 | 41,439 | 97,313 | |
| 1984 | D | 52,294 | 51,046 | 104,148 | |
| 1980 | D | 50,046 | 46,063 | 100,673 | |
| 1976 | D | 59,177 | 40,333 | 101,065 | |
| 1972 | R | 46,636 | 50,519 | 98,097 | |
| 1968 | D | 50,726 | 34,442 | 100,874 | |
| 1964 | D | 74,005 | 28,226 | 102,231 | |
| 1960 | D | 67,367 | 42,046 | 109,751 | |
| 1956 | D | 55,295 | 41,528 | 97,106 | |
| 1952 | D | 60,311 | 39,713 | 100,503 | |
| 1948 | D | 54,260 | 30,883 | 85,617 | |
| 1944 | D | 48,325 | 33,557 | 82,209 | |
| 1940 | D | 53,482 | 35,998 | 89,891 | |
| 1936 | D | 54,238 | 26,684 | 83,762 | |
| 1932 | D | 47,305 | 22,744 | 72,571 | |
| 1928 | D | 36,374 | 31,026 | 68,037 | |
| 1924 | R | 14,921 | 23,380 | 50,994 | |
| 1920 | R | 14,032 | 21,681 | 42,231 | |
| 1916 | D | 22,622 | 22,134 | 46,331 | |
| 1912 | D | 10,826 | 8,156 | 25,866 | |
| 1908 | R | 11,342 | 12,619 | 25,934 | |
| 1904 | R | 8,200 | 11,926 | 21,561 | |
| 1900 | D | 9,827 | 9,764 | 20,063 | |
| 1896 | R | 8,345 | 8,960 | 17,583 | |
| 1892 | D | 7,207 | 6,276 | 14,034 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Demographics
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
American
100.0%
African American
22.3%
Multiple ancestry combinations reported; no single grouping above 1%.
American Indian, Alaska Native, Native Hawaiian, and Pacific Islander combined.
Source · American Community Survey 5-year estimates, 2024 release. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.
Age distribution by sex
Median age: 39.9 in this county, 39.1 nationally
Male
Age
Female
85+
75–84
65–74
55–64
45–54
35–44
25–34
18–24
5–17
<5
Source · American Community Survey 5-year estimates, 2024 release.
Median household income
2024 inflation-adjusted dollars
$73,854
St. Clair County ranks near the middle of US counties.
St. Clair County$73,854
Illinois$83,390
United States$80,734
Source · American Community Survey 5-year estimates, 2024 release.
Poverty rate
All persons below federal poverty line
13.6%
Children face moderate poverty.
Children under 1818.0%
Working age (18–64)100.0%
Seniors (65+)18.0%
Source · American Community Survey 5-year estimates, 2024 release.
Language at home
Population aged 5 and older
0.0%
speak English only
Source · ACS 5-year estimates, 2024.
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 53.6% of residents not counted as adherents by any reporting body.
St. Clair County anchors Illinois's Metro East region across the Mississippi from St. Louis, with a diverse population and urban-suburban mix that has returned Democratic presidential margins in the single to low double digits for over two decades.
The Democratic margin in St. Clair County reached its widest at forty-five points in 1964. The margin in 2024 was eight points — still decisive.
St. Clair County's loyalty is rooted in its place. Median household income of $73,854, a 60% non-Hispanic-white share, and a population of 253,694 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 Marquette County and Rock Island County.
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