Jefferson County, Colorado: Realigning Affluent Suburb county. In 2024, voted D+19%. Democratic peak: D+81 in 1896.
Key facts
- 2024 presidential margin
- D+19MIT Election Lab
- Political typology
- Realigning Affluent SuburbAkashic typology
- Population
- 579,3772024 5-year
- Median household income
- $110,6562024 5-year
- White (non-Hispanic)
- 79.5%2024 5-year
- Black
- 1.2%2024 5-year
- Hispanic / Latino
- 16.1%2024 5-year
- Peak Democratic margin
- D+81 in 1896MIT Election Lab
- Peak Republican margin
- R+47 in 1924MIT Election Lab
- Most similar
- Arapahoe County, CO · similarity 0.98
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.
—
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 | −2.5% |
| 1884 | −6.2% |
| 1888 | −11.1% |
| 1892 | −42.9% |
| 1896 | +80.6% |
| 1900 | +8.2% |
| 1904 | −24.4% |
| 1908 | −0.7% |
| 1912 | +24.2% |
| 1916 | +23.8% |
| 1920 | −28.3% |
| 1924 | −47.1% |
| 1928 | −39.6% |
| 1932 | +4.2% |
| 1936 | +15.7% |
| 1940 | −6.2% |
| 1944 | −14.8% |
| 1948 | −3.9% |
| 1952 | −26.7% |
| 1956 | −27.9% |
| 1960 | −19.5% |
| 1964 | +12.7% |
| 1968 | −21.8% |
| 1972 | −42.3% |
| 1976 | −23.8% |
| 1980 | −34.1% |
| 1984 | −39.2% |
| 1988 | −14.8% |
| 1992 | −0.8% |
| 1996 | −5.7% |
| 2000 | −8.1% |
| 2004 | −5.2% |
| 2008 | +9.0% |
| 2012 | +4.9% |
| 2016 | +6.9% |
| 2020 | +18.5% |
| 2024 | +19.5% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| D | 210,875 | 140,505 | 361,716 | ||
| D | 218,393 | 148,414 | 377,351 | ||
| D | 160,776 | 138,177 | 328,883 | ||
| D | 159,296 | 144,197 | 311,052 | ||
| D | 158,153 | 131,627 | 295,062 | ||
| R | 126,558 | 140,644 | 271,568 | ||
| R | 100,970 | 120,138 | 235,491 | ||
| R | 89,494 | 101,517 | 209,723 | ||
| R | 80,834 | 82,705 | 223,203 | ||
| R | 81,824 | 110,820 | 196,511 | ||
| R | 53,700 | 124,496 | 180,628 | ||
| R | 41,525 | 97,008 | 162,611 | ||
| R | 52,782 | 87,080 | 144,073 | ||
| R | 31,555 | 80,082 | 114,597 | ||
| R | 31,392 | 50,847 | 89,357 | ||
| D | 43,162 | 33,398 | 76,812 | ||
| R | 22,962 | 34,105 | 57,204 | ||
| R | 14,270 | 25,398 | 39,865 | ||
| R | 11,509 | 19,971 | 31,674 | ||
| R | 9,145 | 9,903 | 19,308 | ||
| R | 7,277 | 9,815 | 17,160 | ||
| R | 7,745 | 8,780 | 16,625 | ||
| D | 7,283 | 5,271 | 12,825 | ||
| D | 6,023 | 5,522 | 12,048 | ||
| R | 2,880 | 6,754 | 9,775 | ||
| R | 1,271 | 4,869 | 7,645 | ||
| R | 1,941 | 3,593 | 5,840 | ||
| D | 3,368 | 2,040 | 5,574 | ||
| D | 2,309 | 1,011 | 5,357 | ||
| R | 2,583 | 2,623 | 5,399 | ||
| R | 1,739 | 2,903 | 4,778 | ||
| D | 2,138 | 1,807 | 4,034 | ||
| D | 3,176 | 300 | 3,569 | ||
| O | 0 | 792 | 1,848 | ||
| R | 767 | 970 | 1,833 | ||
| R | 743 | 845 | 1,658 | ||
| R | 790 | 832 | 1,679 | ||
| — | — | — | — |
Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
21.0%
English
14.7%
Irish
13.4%
Italian
6.5%
American
3.4%
Polish
3.2%
Scottish
2.8%
African American
1.0%
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: 40.5 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.
2024 ACS
Median household income
Inflation-adjusted dollars
$110,656
Jefferson County ranks in the top 0.5% of US counties.
Jefferson County$110,656
Colorado$95,470
United States$80,734
Jefferson County ranks in the top 0.5% 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
6.7%
Child poverty is below the national average.
Children under 187.0%
Working age (18–64)6.5%
Seniors (65+)7.9%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
90.0%
speak English only
Spanish5.8%
Other Indo-European2.0%
Asian & Pacific Islander1.7%
Other languages0.5%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 68.9% of residents not counted as adherents by any reporting body.
Jefferson County's electorate has trended sharply leftward since the early 2000s, with its mix of educated suburban households and Front Range growth driving a 2024 presidential margin of nearly 20 points — a dramatic reversal from its longtime Republican lean.
Once reliably Republican — a margin of forty-seven points in 1924 at its widest — Jefferson County has trended Democratic. Between 2020 and 2024 the county moved one point toward the Democratic candidate; the 2024 margin was nineteen points.
A median household income of $110,656 — among the higher at this geographic scale — and a population of 579,377 describe the county. The county's voting pattern over the last decade is most similar to that of Arapahoe County and Larimer 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, Colorado. Akashic. https://akashic.app/county/08059/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
More realigning affluent suburb counties
Frequently asked questions
How did Jefferson County, Colorado vote in 2024?
In 2024, Jefferson County, Colorado voted Democratic by 19.5 points (D+19), carried by the Democratic candidate. Out of 361,716 votes cast, 210,875 went Democratic and 140,505 went Republican.
What is Jefferson County, Colorado's political typology?
Akashic places Jefferson County, Colorado in the "Realigning Affluent Suburb" typology — College-educated, affluent suburbs — the one bloc moving toward the Democratic Party. 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 12 times, Republican 24 times, and other 1 times.
When did Jefferson County, Colorado last vote Republican?
The most recent presidential election in which Jefferson County, Colorado voted Republican was 2004.
How many people live in Jefferson County, Colorado?
Jefferson County, Colorado has a population of 579,377 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Jefferson County, Colorado?
Median household income in Jefferson County, Colorado is $110,656 — above the national median of $80,734. The Colorado state median is $95,470.
What is the political history of Jefferson County, Colorado?
Akashic tracks 38 presidential elections in Jefferson County, Colorado from 1876 to 2024. Of those, 12 went Democratic and 24 went Republican. The county's typology — "Realigning Affluent Suburb" — captures where that record, its demographics, and its recent swing place it among American communities.