Jefferson County, Colorado

2024 results by precinct

296 precincts · 361,716 votes cast

Harris · D+19

Harris +50

Trump +50

Real precinct boundaries. Hover for vote totals.

38 presidential elections

Year	Won	Margin	Democratic	Republican	Total
2024	D	+19.5%	210,875	140,505	361,716
2020	D	+18.5%	218,393	148,414	377,351
2016	D	+6.9%	160,776	138,177	328,883
2012	D	+4.9%	159,296	144,197	311,052
2008	D	+9.0%	158,153	131,627	295,062
2004	R	−5.2%	126,558	140,644	271,568
2000	R	−8.1%	100,970	120,138	235,491
1996	R	−5.7%	89,494	101,517	209,723
1992	R	−0.8%	80,834	82,705	223,203
1988	R	−14.8%	81,824	110,820	196,511
1984	R	−39.2%	53,700	124,496	180,628
1980	R	−34.1%	41,525	97,008	162,611
1976	R	−23.8%	52,782	87,080	144,073
1972	R	−42.3%	31,555	80,082	114,597
1968	R	−21.8%	31,392	50,847	89,357
1964	D	+12.7%	43,162	33,398	76,812
1960	R	−19.5%	22,962	34,105	57,204
1956	R	−27.9%	14,270	25,398	39,865
1952	R	−26.7%	11,509	19,971	31,674
1948	R	−3.9%	9,145	9,903	19,308
1944	R	−14.8%	7,277	9,815	17,160
1940	R	−6.2%	7,745	8,780	16,625
1936	D	+15.7%	7,283	5,271	12,825
1932	D	+4.2%	6,023	5,522	12,048
1928	R	−39.6%	2,880	6,754	9,775
1924	R	−47.1%	1,271	4,869	7,645
1920	R	−28.3%	1,941	3,593	5,840
1916	D	+23.8%	3,368	2,040	5,574
1912	D	+24.2%	2,309	1,011	5,357
1908	R	−0.7%	2,583	2,623	5,399
1904	R	−24.4%	1,739	2,903	4,778
1900	D	+8.2%	2,138	1,807	4,034
1896	D	+80.6%	3,176	300	3,569
1892	R	−42.9%	0	792	1,848
1888	R	−11.1%	767	970	1,833
1884	R	−6.2%	743	845	1,658
1880	R	−2.5%	790	832	1,679
1876	—	No data	—	—	—

Demographics

Race, ethnicity, and ancestry

Click any group to see the ancestries typically reported within it.

American

100.0%

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. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.

Age distribution by sex

Median age: 40.5 in this county, 39.1 nationally

Male

Age

Female

0.8%

85+

1.1%

2.2%

75–84

2.9%

5.2%

65–74

5.7%

6.4%

55–64

6.8%

6.3%

45–54

6.1%

7.9%

35–44

7.3%

8.0%

25–34

7.3%

3.9%

18–24

3.5%

7.1%

5–17

6.7%

2.4%

2.3%

Source · American Community Survey 5-year estimates, 2024 release.

Median household income

2024 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

Source · American Community Survey 5-year estimates, 2024 release.

Poverty rate

All persons below federal poverty line

6.7%

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

Other Christian

13.7%

Catholic & Orthodox

12.0%

Mainline Protestant

2.8%

Baptist

0.9%

Non-Christian

0.7%

Pentecostal & Holiness

0.5%

Methodist

0.5%

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.

The 2008 election was the turning point, when the Democratic candidate carried the county by nine points. The 2024 margin was nineteen points, in line with the county's new direction.

The demographics suggest why. A population of 579,377, a 80% non-Hispanic-white share, and a median household income of $110,656 situate the county in the broader realignment patterns of recent cycles. The county's voting pattern over the last decade is most similar to that of Arapahoe County and Larimer County.

Most similar counties

Jefferson County changed direction in the last decade.