Johnson County, Iowa: Diversifying Metro county. In 2024, voted D+38%. Democratic peak: D+43 in 2020.
Key facts
- 2024 presidential margin
- D+38MIT Election Lab
- Political typology
- Diversifying MetroAkashic typology
- Population
- 156,6392024 5-year
- Median household income
- $74,9352024 5-year
- White (non-Hispanic)
- 76.4%2024 5-year
- Black
- 7.7%2024 5-year
- Hispanic / Latino
- 6.7%2024 5-year
- Peak Democratic margin
- D+43 in 2020MIT Election Lab
- Peak Republican margin
- R+16 in 1952MIT Election Lab
- Most similar
- Santa Fe County, NM · similarity 0.99
2024 results by precinct
2024 precinct map of Johnson CountyPrecinct-level 2024 presidential results for Johnson 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 | No data |
| 1884 | No data |
| 1888 | No data |
| 1892 | +18.9% |
| 1896 | +4.2% |
| 1900 | +2.7% |
| 1904 | +2.0% |
| 1908 | +9.0% |
| 1912 | +28.6% |
| 1916 | +14.8% |
| 1920 | −6.1% |
| 1924 | −9.1% |
| 1928 | −0.7% |
| 1932 | +22.6% |
| 1936 | +21.5% |
| 1940 | +11.1% |
| 1944 | +13.7% |
| 1948 | +9.0% |
| 1952 | −16.4% |
| 1956 | −12.6% |
| 1960 | −1.7% |
| 1964 | +36.3% |
| 1968 | +8.3% |
| 1972 | +16.8% |
| 1976 | +10.6% |
| 1980 | +15.1% |
| 1984 | +16.3% |
| 1988 | +29.8% |
| 1992 | +28.2% |
| 1996 | +31.7% |
| 2000 | +25.2% |
| 2004 | +29.3% |
| 2008 | +41.5% |
| 2012 | +35.5% |
| 2016 | +37.6% |
| 2020 | +43.2% |
| 2024 | +37.8% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| D | 58,846 | 26,087 | 86,644 | ||
| D | 59,177 | 22,925 | 83,851 | ||
| D | 50,200 | 21,044 | 77,476 | ||
| D | 50,666 | 23,698 | 75,977 | ||
| D | 51,027 | 20,732 | 72,975 | ||
| D | 41,847 | 22,715 | 65,373 | ||
| D | 31,174 | 17,899 | 52,769 | ||
| D | 27,888 | 13,402 | 45,732 | ||
| D | 28,656 | 14,041 | 51,774 | ||
| D | 28,759 | 15,453 | 44,647 | ||
| D | 26,000 | 18,677 | 45,044 | ||
| D | 20,122 | 13,642 | 42,997 | ||
| D | 20,208 | 16,090 | 38,710 | ||
| D | 20,922 | 14,823 | 36,236 | ||
| D | 13,541 | 11,384 | 25,944 | ||
| D | 14,717 | 6,860 | 21,618 | ||
| R | 10,563 | 10,927 | 21,508 | ||
| R | 8,767 | 11,298 | 20,076 | ||
| R | 8,067 | 11,231 | 19,350 | ||
| D | 8,611 | 7,139 | 16,303 | ||
| D | 8,434 | 6,396 | 14,897 | ||
| D | 9,017 | 7,206 | 16,278 | ||
| D | 8,794 | 5,629 | 14,743 | ||
| D | 8,764 | 5,484 | 14,483 | ||
| R | 7,181 | 7,288 | 14,498 | ||
| R | 4,570 | 5,741 | 12,891 | ||
| R | 5,032 | 5,696 | 10,923 | ||
| D | 3,650 | 2,704 | 6,403 | ||
| D | 3,327 | 1,645 | 5,886 | ||
| D | 3,314 | 2,758 | 6,151 | ||
| D | 3,085 | 2,963 | 6,139 | ||
| D | 3,182 | 3,010 | 6,258 | ||
| D | 3,170 | 2,910 | 6,184 | ||
| D | 3,227 | 2,179 | 5,537 | ||
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Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
28.0%
Irish
14.5%
English
11.8%
Italian
3.1%
American
2.9%
Polish
2.2%
Scottish
1.7%
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. 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: 31.0 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
$74,935
Johnson County ranks in the top 25% of US counties.
Johnson County$74,935
Iowa$75,059
United States$80,734
Johnson 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
17.1%
Child poverty is below the national average.
Children under 1811.1%
Working age (18–64)19.5%
Seniors (65+)5.4%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
85.3%
speak English only
Spanish4.3%
Other Indo-European3.9%
Asian & Pacific Islander3.6%
Other languages3.0%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
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 here reached forty-three points in 2020. Between 2020 and 2024 the county moved five points toward the Republican candidate; the 2024 margin was thirty-eight points.
A population of 156,639, a 76% non-Hispanic-white share, and a median household income of $74,935 describe the county. The county's voting pattern over the last decade is most similar to that of Santa Fe County and Bullock 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.
Johnson County, Iowa. Akashic. https://akashic.app/county/19103/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
More diversifying metro counties
Frequently asked questions
How did Johnson County, Iowa vote in 2024?
In 2024, Johnson County, Iowa voted Democratic by 37.8 points (D+38), carried by the Democratic candidate. Out of 86,644 votes cast, 58,846 went Democratic and 26,087 went Republican.
What is Johnson County, Iowa's political typology?
Akashic places Johnson County, Iowa in the "Diversifying Metro" typology — Mid-size metropolitan counties growing more diverse and trending Democratic. 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 28 times, Republican 6 times, and other 0 times.
When did Johnson County, Iowa last vote Republican?
The most recent presidential election in which Johnson County, Iowa voted Republican was 1960.
How many people live in Johnson County, Iowa?
Johnson County, Iowa has a population of 156,639 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Johnson County, Iowa?
Median household income in Johnson County, Iowa is $74,935 — below the national median of $80,734. The Iowa state median is $75,059.
What is the political history of Johnson County, Iowa?
Akashic tracks 38 presidential elections in Johnson County, Iowa from 1876 to 2024. Of those, 28 went Democratic and 6 went Republican. The county's typology — "Diversifying Metro" — captures where that record, its demographics, and its recent swing place it among American communities.