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 | 107,558 | 52,274 | 163,779 | |
| 2020 | D | 122,532 | 51,641 | 175,600 | |
| 2016 | D | 104,775 | 46,193 | 158,058 | |
| 2012 | D | 104,377 | 47,355 | 155,355 | |
| 2008 | D | 107,926 | 50,223 | 160,039 | |
| 2004 | D | 91,580 | 56,604 | 149,510 | |
| 2000 | D | 83,256 | 46,670 | 135,559 | |
| 1996 | D | 77,641 | 40,559 | 131,726 | |
| 1992 | D | 71,383 | 50,473 | 145,260 | |
| 1988 | D | 68,712 | 65,384 | 135,345 | |
| 1984 | R | 66,398 | 71,195 | 138,121 | |
| 1980 | D | 60,888 | 53,450 | 128,582 | |
| 1976 | D | 69,621 | 58,453 | 130,856 | |
| 1972 | R | 62,180 | 69,303 | 133,191 | |
| 1968 | D | 63,218 | 45,354 | 125,529 | |
| 1964 | D | 86,985 | 35,081 | 122,214 | |
| 1960 | D | 74,166 | 46,924 | 121,269 | |
| 1956 | R | 52,684 | 56,029 | 109,105 | |
| 1952 | D | 57,751 | 50,423 | 108,662 | |
| 1948 | D | 49,690 | 37,794 | 89,436 | |
| 1944 | D | 52,383 | 36,844 | 89,371 | |
| 1940 | D | 50,121 | 37,190 | 87,533 | |
| 1936 | D | 47,702 | 29,283 | 77,564 | |
| 1932 | R | 30,284 | 33,715 | 66,879 | |
| 1928 | R | 27,908 | 41,056 | 69,338 | |
| 1924 | R | 14,639 | 30,689 | 51,551 | |
| 1920 | R | 15,713 | 29,626 | 46,683 | |
| 1916 | R | 10,621 | 14,213 | 25,493 | |
| 1912 | D | 7,773 | 5,676 | 21,120 | |
| 1908 | R | 9,289 | 14,941 | 25,329 | |
| 1904 | R | 8,527 | 14,900 | 24,467 | |
| 1900 | R | 7,858 | 13,874 | 22,498 | |
| 1896 | R | 5,970 | 13,847 | 20,718 | |
| 1892 | R | 9,348 | 9,795 | 19,671 | |
| 1888 | — | — | — | — | |
| 1884 | — | — | — | — | |
| 1880 | — | — | — | — | |
| 1876 | — | — | — | — |
Demographics
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
American
100.0%
Polish
0.6%
African American
14.8%
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: 39.5 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
$100,645
Mercer County ranks in the top 5% of US counties.
Mercer County$100,645
New Jersey$103,556
United States$80,734
Source · American Community Survey 5-year estimates, 2024 release.
Poverty rate
All persons below federal poverty line
10.3%
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 52.1% of residents not counted as adherents by any reporting body.
Mercer County anchors New Jersey's political center of gravity around Trenton, returning Democratic presidential margins above 30 points in recent cycles while housing a mix of urban wards, suburban townships, and Princeton's academic community.
The Democratic margin in Mercer County reached its widest at forty-two points in 1964. The margin in 2024 was thirty-four points — still decisive.
Mercer County's loyalty is rooted in its place. Median household income of $100,645, a 46% non-Hispanic-white share, and a population of 385,864 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 DeKalb County and Norfolk city.
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