Voter file loaded July 30, 2026 · figures are from that file, held as a fixed record
St. Clair County, Michigan has 138,498 active registered voters across 62 precincts, as of August 2026.
Party registration
Michigan doesn't register voters by party, so there's no party breakdown to show. Party lean is usually inferred from primary participation; that data is in the voter file and available inside Motion51.
Most reliable-voting precincts
| # | Precinct | Active voters | Supervoters | Supervoter % |
|---|---|---|---|---|
| 1 | CLAY TOWNSHIP P4 | 947 | 659 | 69.59% |
| 2 | COLUMBUS TOWNSHIP P1 | 2,026 | 1,153 | 56.91% |
| 3 | CASCO TOWNSHIP P2 | 1,678 | 952 | 56.73% |
| 4 | CHINA TOWNSHIP P1 | 1,752 | 990 | 56.51% |
| 5 | RILEY TOWNSHIP P1 | 2,817 | 1,578 | 56.02% |
| 6 | EAST CHINA TOWNSHIP P1 | 3,232 | 1,808 | 55.94% |
| 7 | ST CLAIR TOWNSHIP P1 | 3,359 | 1,878 | 55.91% |
| 8 | IRA TOWNSHIP P2 | 2,096 | 1,159 | 55.3% |
| 9 | BERLIN TOWNSHIP P1 | 2,654 | 1,464 | 55.16% |
| 10 | ST CLAIR CITY P1 | 1,487 | 820 | 55.14% |
Supervoters are active registered voters who cast a ballot in at least 3 of the last 4 November general elections (2018–2024). Percentages are precinct totals from the official state voter file — no individual voter information is shown. Precincts with fewer than 400 active voters are excluded.
How St. Clair County voted for president
Election results are public records.
St. Clair County at a glance.
St. Clair County had an estimated 160,308 residents in July 2024, the 13th most populous of Michigan's 83 counties, down 0.1% since the 2020 census. Of those, 128,684 are 18 or older, the voting-age population, and 21.7% are 65 or older. Its 138,498 active registered voters equal about 107.6% of that voting-age population.
It covers 722 square miles of land (222 people per square mile). The largest towns and cities are Port Huron (28,342), Fort Gratiot (11,693), Port Huron (10,669), Marysville (9,868) and Kimball (9,625). The American Community Survey (2020-2024) puts it at a median age of 44.5, a median household income of $71,270, 20.3% of adults 25 and older holding a bachelor's degree or higher and 80.8% of occupied homes owned by the people living in them.
In 2024, 96,519 votes were cast for president, about 75.0% of the voting-age population; the Democratic ticket took 32.0% and the Republican ticket 66.6%. The two-party margin moved from D+2.7 in 2008 to R+34.6 in 2024.
- Population (2024 estimate)
- 160,308
- Population (2020 census base)
- 160,390
- Voting-age population (18+)
- 128,684
- Active voters per 100 adults
- 107.6
- Residents 65 and older
- 21.7%
- People per square mile
- 222
- Land area
- 722 sq mi
- Median age
- 44.5
- Median household income
- $71,270
- Adults 25+ with a bachelor's degree
- 20.3%
- Owner-occupied homes
- 80.8%
Largest towns and cities
- Port Huron 28,342
- Fort Gratiot 11,693
- Port Huron 10,669
- Marysville 9,868
- Kimball 9,625
Presidential vote, 2008–2024
| Year | Democratic | Republican | Margin | Votes cast |
|---|---|---|---|---|
| 2024 | 32.0% | 66.6% | R+34.6 | 96,519 |
| 2020 | 34.1% | 64.3% | R+30.2 | 92,064 |
| 2016 | 31.5% | 62.9% | R+31.4 | 77,994 |
| 2012 | 45.9% | 53.0% | R+7.1 | 73,740 |
| 2008 | 50.3% | 47.6% | D+2.7 | 80,900 |
Sources: U.S. Census Bureau Vintage 2024 population estimates and 2024 Gazetteer; American Community Survey 2020–2024 5-year estimates; certified county presidential returns. Growth, density and turnout are simple arithmetic on those figures.
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