O'Brien County, Iowa: Farm Belt county. In 2024, voted R+61%. Republican peak: R+61 in 2024.
Key facts
- 2024 presidential margin
- R+61MIT Election Lab
- Political typology
- Farm BeltAkashic typology
- Population
- 14,1262024 5-year
- Median household income
- $68,3562024 5-year
- White (non-Hispanic)
- 87.5%2024 5-year
- Black
- 1.7%2024 5-year
- Hispanic / Latino
- 7.6%2024 5-year
- Peak Democratic margin
- D+23 in 1912MIT Election Lab
- Peak Republican margin
- R+61 in 2024MIT Election Lab
- Most similar
- Osceola County, IA · similarity 1.00
2024 results by precinct
2024 precinct map of O'Brien CountyPrecinct-level 2024 presidential results for O'Brien 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 | −9.3% |
| 1896 | −21.3% |
| 1900 | −23.7% |
| 1904 | −42.2% |
| 1908 | −17.7% |
| 1912 | +22.9% |
| 1916 | −6.1% |
| 1920 | −54.6% |
| 1924 | −47.9% |
| 1928 | −33.5% |
| 1932 | +16.4% |
| 1936 | +20.8% |
| 1940 | −7.0% |
| 1944 | −12.4% |
| 1948 | −3.8% |
| 1952 | −52.8% |
| 1956 | −34.7% |
| 1960 | −37.4% |
| 1964 | −0.5% |
| 1968 | −42.7% |
| 1972 | −39.2% |
| 1976 | −25.5% |
| 1980 | −35.1% |
| 1984 | −33.4% |
| 1988 | −20.8% |
| 1992 | −23.1% |
| 1996 | −24.4% |
| 2000 | −35.5% |
| 2004 | −38.8% |
| 2008 | −34.9% |
| 2012 | −44.9% |
| 2016 | −59.5% |
| 2020 | −56.8% |
| 2024 | −60.7% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| R | 1,428 | 5,998 | 7,525 | ||
| R | 1,569 | 5,861 | 7,551 | ||
| R | 1,315 | 5,752 | 7,460 | ||
| R | 1,969 | 5,266 | 7,341 | ||
| R | 2,338 | 4,894 | 7,333 | ||
| R | 2,330 | 5,328 | 7,731 | ||
| R | 2,170 | 4,674 | 7,044 | ||
| R | 2,236 | 3,877 | 6,735 | ||
| R | 2,122 | 3,869 | 7,578 | ||
| R | 2,768 | 4,241 | 7,072 | ||
| R | 2,479 | 5,008 | 7,569 | ||
| R | 2,210 | 4,937 | 7,761 | ||
| R | 2,732 | 4,643 | 7,506 | ||
| R | 2,224 | 5,159 | 7,491 | ||
| R | 2,146 | 5,594 | 8,068 | ||
| R | 4,295 | 4,336 | 8,637 | ||
| R | 2,967 | 6,509 | 9,480 | ||
| R | 2,970 | 6,138 | 9,118 | ||
| R | 2,192 | 7,130 | 9,360 | ||
| R | 3,421 | 3,697 | 7,326 | ||
| R | 3,138 | 4,033 | 7,201 | ||
| R | 4,133 | 4,760 | 8,931 | ||
| D | 5,139 | 3,350 | 8,612 | ||
| D | 4,503 | 3,213 | 7,848 | ||
| R | 2,397 | 4,845 | 7,298 | ||
| R | 756 | 4,172 | 7,135 | ||
| R | 1,468 | 5,137 | 6,714 | ||
| R | 1,787 | 2,021 | 3,847 | ||
| O | 1,506 | 620 | 3,870 | ||
| R | 1,326 | 1,912 | 3,314 | ||
| R | 885 | 2,279 | 3,306 | ||
| R | 1,461 | 2,386 | 3,901 | ||
| R | 1,562 | 2,421 | 4,028 | ||
| R | 1,373 | 1,666 | 3,147 | ||
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Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
39.7%
Irish
7.8%
American
5.8%
English
5.6%
Italian
1.1%
French
0.7%
Scottish
0.7%
African American
1.4%
Multiple ancestry combinations reported; no single grouping above 1%.
Sample size too small to break out by ancestry reliably.
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: 39.5 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
$68,356
O'Brien County ranks near the middle of US counties.
O'Brien County$68,356
Iowa$75,059
United States$80,734
O'Brien County ranks near the middle 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
13.3%
Children face moderate poverty.
Children under 1820.7%
Working age (18–64)10.9%
Seniors (65+)10.2%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
92.4%
speak English only
Spanish5.7%
Other languages1.0%
Other Indo-European0.6%
Asian & Pacific Islander0.3%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 34.9% of residents not counted as adherents by any reporting body.
O'Brien County's R+60.7 margin in 2024 places it among the most one-sided presidential counties in Iowa, reflecting the broader rural realignment that has reshaped the state's electoral map over the past decade.
The Republican margin here reached sixty-one points in 2024. Between 2020 and 2024 the county moved four points toward the Republican candidate; the 2024 margin was sixty-one points.
A population of 14,126, a 88% non-Hispanic-white share, and a median household income of $68,356 describe an agricultural county. The county's voting pattern over the last decade is most similar to that of Osceola County and Franklin 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.
O'Brien County, Iowa. Akashic. https://akashic.app/county/19141/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
More farm belt counties
Frequently asked questions
How did O'Brien County, Iowa vote in 2024?
In 2024, O'Brien County, Iowa voted Republican by 60.7 points (R+61), carried by the Republican candidate. Out of 7,525 votes cast, 1,428 went Democratic and 5,998 went Republican.
What is O'Brien County, Iowa's political typology?
Akashic places O'Brien County, Iowa 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 2 times, Republican 31 times, and other 1 times.
When did O'Brien County, Iowa last vote Democratic?
The most recent presidential election in which O'Brien County, Iowa voted Democratic was 1936.
How many people live in O'Brien County, Iowa?
O'Brien County, Iowa has a population of 14,126 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in O'Brien County, Iowa?
Median household income in O'Brien County, Iowa is $68,356 — below the national median of $80,734. The Iowa state median is $75,059.
What is the political history of O'Brien County, Iowa?
Akashic tracks 38 presidential elections in O'Brien County, Iowa from 1876 to 2024. Of those, 2 went Democratic and 31 went Republican. The county's typology — "Farm Belt" — captures where that record, its demographics, and its recent swing place it among American communities.