Jefferson County, Missouri: Farm Belt county. In 2024, voted R+37%. Democratic peak: D+41 in 1964.
Key facts
- 2024 presidential margin
- R+37MIT Election Lab
- Political typology
- Farm BeltAkashic typology
- Population
- 229,4582024 5-year
- Median household income
- $82,8512024 5-year
- White (non-Hispanic)
- 89.3%2024 5-year
- Black
- 1.0%2024 5-year
- Hispanic / Latino
- 2.6%2024 5-year
- Peak Democratic margin
- D+41 in 1964MIT Election Lab
- Peak Republican margin
- R+37 in 2024MIT Election Lab
- Most similar
- Washington County, MO · similarity 0.99
2024 results by precinct
2024 precinct map of Jefferson CountyPrecinct-level 2024 presidential results for Jefferson County, with each precinct boundary colored by Democratic-vs-Republican margin.
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Margin—
Turnout—
Harris +50Trump +50
Real precinct boundaries. Hover for vote totals.
presidential history
Presidential margin, 1876–2024
Democratic minus Republican, by election
| Year | Margin (D minus R) |
|---|---|
| 1876 | No data |
| 1880 | No data |
| 1884 | No data |
| 1888 | No data |
| 1892 | +8.3% |
| 1896 | −1.6% |
| 1900 | +0.4% |
| 1904 | −6.2% |
| 1908 | −6.0% |
| 1912 | +4.6% |
| 1916 | −4.5% |
| 1920 | −9.9% |
| 1924 | −5.2% |
| 1928 | −9.1% |
| 1932 | +27.8% |
| 1936 | +23.9% |
| 1940 | +11.9% |
| 1944 | +8.1% |
| 1948 | +25.5% |
| 1952 | +14.3% |
| 1956 | +12.8% |
| 1960 | +13.8% |
| 1964 | +41.1% |
| 1968 | +4.9% |
| 1972 | −22.8% |
| 1976 | +15.7% |
| 1980 | −8.2% |
| 1984 | −26.6% |
| 1988 | −2.7% |
| 1992 | +16.2% |
| 1996 | +12.4% |
| 2000 | +2.4% |
| 2004 | −0.6% |
| 2008 | +2.5% |
| 2012 | −12.7% |
| 2016 | −35.0% |
| 2020 | −33.4% |
| 2024 | −36.6% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| R | 36,965 | 80,796 | 119,833 | ||
| R | 37,856 | 77,046 | 117,286 | ||
| R | 31,568 | 69,036 | 106,995 | ||
| R | 41,564 | 53,978 | 98,024 | ||
| D | 53,467 | 50,804 | 105,704 | ||
| R | 46,057 | 46,624 | 93,264 | ||
| D | 38,616 | 36,766 | 77,204 | ||
| D | 32,073 | 23,877 | 66,102 | ||
| D | 32,569 | 20,637 | 73,501 | ||
| R | 27,738 | 29,279 | 57,232 | ||
| R | 20,026 | 34,525 | 54,551 | ||
| R | 24,042 | 28,546 | 54,882 | ||
| D | 25,159 | 18,261 | 43,915 | ||
| R | 13,787 | 21,947 | 35,734 | ||
| D | 13,230 | 11,708 | 31,053 | ||
| D | 18,916 | 7,887 | 26,803 | ||
| D | 17,054 | 12,910 | 29,964 | ||
| D | 13,868 | 10,712 | 24,580 | ||
| D | 12,808 | 9,607 | 22,437 | ||
| D | 10,280 | 6,085 | 16,435 | ||
| D | 7,953 | 6,758 | 14,745 | ||
| D | 9,553 | 7,517 | 17,115 | ||
| D | 9,158 | 5,575 | 14,974 | ||
| D | 8,130 | 4,559 | 12,844 | ||
| R | 5,231 | 6,285 | 11,538 | ||
| R | 4,356 | 4,870 | 9,963 | ||
| R | 4,684 | 5,730 | 10,595 | ||
| R | 3,021 | 3,310 | 6,489 | ||
| D | 2,368 | 2,127 | 5,208 | ||
| R | 2,698 | 3,050 | 5,865 | ||
| R | 2,560 | 2,909 | 5,585 | ||
| D | 2,798 | 2,775 | 5,640 | ||
| R | 2,785 | 2,876 | 5,699 | ||
| D | 2,617 | 2,207 | 4,937 | ||
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Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
29.2%
Irish
14.6%
English
11.3%
American
6.2%
Italian
5.3%
French
4.4%
Polish
2.1%
African American
0.8%
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. Hispanic/Latino is an ethnicity that overlaps the race categories, so these shares can total more than 100%. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.
2024 ACS
Age distribution by sex
Median age: 40.3 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.
2024 ACS
Median household income
Inflation-adjusted dollars
$82,851
Jefferson County ranks in the top 25% of US counties.
Jefferson County$82,851
Missouri$70,702
United States$80,734
Jefferson County ranks in the top 25% of US counties by median household income.
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Poverty rate
All persons below federal poverty line
9.0%
Child poverty is below the national average.
Children under 1811.6%
Working age (18–64)8.2%
Seniors (65+)9.1%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
96.7%
speak English only
Other Indo-European1.3%
Spanish1.1%
Asian & Pacific Islander0.7%
Other languages0.2%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 64.9% of residents not counted as adherents by any reporting body.
Once a competitive swing county on St. Louis's southern fringe, Jefferson has moved decisively toward Republican presidential candidates since 2000, reflecting a broader realignment among working-class white voters in Missouri's outer suburbs.
The Republican margin here reached thirty-seven points in 2024. Between 2020 and 2024 the county moved three points toward the Republican candidate; the 2024 margin was thirty-seven points.
A population of 229,458, a 89% non-Hispanic-white share, and a median household income of $82,851 describe an agricultural county. The county's voting pattern over the last decade is most similar to that of Washington County and St. Francois County.
Most similar counties
Compare two places, side by side
Twelve curated comparisons line up election history, demographics, and the divergence story for two places at a glance. Browse all comparisons →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
Jefferson County, Missouri. Akashic. https://akashic.app/county/29099/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
More farm belt counties
Frequently asked questions
How did Jefferson County, Missouri vote in 2024?
In 2024, Jefferson County, Missouri voted Republican by 36.6 points (R+37), carried by the Republican candidate. Out of 119,833 votes cast, 36,965 went Democratic and 80,796 went Republican.
What is Jefferson County, Missouri's political typology?
Akashic places Jefferson County, Missouri in the "Farm Belt" typology — Rural Plains and Midwest farm counties — Republican, with modest recent movement. The typology is a data-driven cluster built from vote share, vote swing, race and ethnicity, income, language spoken at home, religion, and ancestry. Across 38 elections in the dataset, the county has voted Democratic 18 times, Republican 16 times, and other 0 times.
When did Jefferson County, Missouri last vote Democratic?
The most recent presidential election in which Jefferson County, Missouri voted Democratic was 2008.
How many people live in Jefferson County, Missouri?
Jefferson County, Missouri has a population of 229,458 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Jefferson County, Missouri?
Median household income in Jefferson County, Missouri is $82,851 — above the national median of $80,734. The Missouri state median is $70,702.
What is the political history of Jefferson County, Missouri?
Akashic tracks 38 presidential elections in Jefferson County, Missouri from 1876 to 2024. Of those, 18 went Democratic and 16 went Republican. The county's typology — "Farm Belt" — captures where that record, its demographics, and its recent swing place it among American communities.