Johnson County, Iowa

2024 results by precinct

65 precincts · 86,644 votes cast

Harris · D+38

Harris +50

Trump +50

Real precinct boundaries. Hover for vote totals.

38 presidential elections

Year	Won	Margin	Democratic	Republican	Total
2024	D	+37.8%	58,846	26,087	86,644
2020	D	+43.2%	59,177	22,925	83,851
2016	D	+37.6%	50,200	21,044	77,476
2012	D	+35.5%	50,666	23,698	75,977
2008	D	+41.5%	51,027	20,732	72,975
2004	D	+29.3%	41,847	22,715	65,373
2000	D	+25.2%	31,174	17,899	52,769
1996	D	+31.7%	27,888	13,402	45,732
1992	D	+28.2%	28,656	14,041	51,774
1988	D	+29.8%	28,759	15,453	44,647
1984	D	+16.3%	26,000	18,677	45,044
1980	D	+15.1%	20,122	13,642	42,997
1976	D	+10.6%	20,208	16,090	38,710
1972	D	+16.8%	20,922	14,823	36,236
1968	D	+8.3%	13,541	11,384	25,944
1964	D	+36.3%	14,717	6,860	21,618
1960	R	−1.7%	10,563	10,927	21,508
1956	R	−12.6%	8,767	11,298	20,076
1952	R	−16.4%	8,067	11,231	19,350
1948	D	+9.0%	8,611	7,139	16,303
1944	D	+13.7%	8,434	6,396	14,897
1940	D	+11.1%	9,017	7,206	16,278
1936	D	+21.5%	8,794	5,629	14,743
1932	D	+22.6%	8,764	5,484	14,483
1928	R	−0.7%	7,181	7,288	14,498
1924	R	−9.1%	4,570	5,741	12,891
1920	R	−6.1%	5,032	5,696	10,923
1916	D	+14.8%	3,650	2,704	6,403
1912	D	+28.6%	3,327	1,645	5,886
1908	D	+9.0%	3,314	2,758	6,151
1904	D	+2.0%	3,085	2,963	6,139
1900	D	+2.7%	3,182	3,010	6,258
1896	D	+4.2%	3,170	2,910	6,184
1892	D	+18.9%	3,227	2,179	5,537
1888	—	No data	—	—	—
1884	—	No data	—	—	—
1880	—	No data	—	—	—
1876	—	No data	—	—	—

Demographics

Race, ethnicity, and ancestry

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

American

100.0%

Polish

1.0%

African American

6.2%

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: 31.0 in this county, 39.1 nationally

Male

Age

Female

0.5%

85+

1.0%

1.7%

75–84

2.1%

3.8%

65–74

4.2%

4.7%

55–64

4.8%

5.0%

45–54

4.8%

6.5%

35–44

6.0%

7.7%

25–34

7.1%

10.0%

18–24

10.8%

7.1%

5–17

6.9%

2.8%

2.5%

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

Median household income

2024 inflation-adjusted dollars

$74,935

Johnson County ranks in the top 25% of US counties.

Johnson County$74,935

Iowa$75,059

United States$80,734

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

Poverty rate

All persons below federal poverty line

17.1%

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

Catholic & Orthodox

11.8%

Mainline Protestant

5.7%

Other Christian

4.4%

Methodist

3.9%

Pentecostal & Holiness

2.0%

Non-Christian

1.7%

Baptist

0.3%

Source · 2020 US Religion Census. Remaining 70.2% of residents not counted as adherents by any reporting body.

Home to the University of Iowa in Iowa City, Johnson County delivers Democratic margins above 35 points in cycles where the rest of the state trends Republican — a pattern driven by a student and academic-professional population that skews younger and more educated than Iowa's norm.

The Democratic margin in Johnson County reached its widest at forty-three points in 2020. The margin in 2024 was thirty-eight points — still decisive.

Johnson County's loyalty is rooted in its place. Median household income of $74,935, a 76% non-Hispanic-white share, and a population of 156,639 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 Santa Fe County and Bullock County.

Most similar counties

Johnson County has voted Democratic for as long as anyone can remember.