Ada County, Idaho: Industrial Catholic Metro county. In 2024, voted R+10%. Republican peak: R+47 in 1904.
Key facts
- 2024 presidential margin
- R+10MIT Election Lab
- Political typology
- Industrial Catholic MetroAkashic typology
- Population
- 518,9352024 5-year
- Median household income
- $91,5022024 5-year
- White (non-Hispanic)
- 83.1%2024 5-year
- Black
- 1.3%2024 5-year
- Hispanic / Latino
- 9.8%2024 5-year
- Peak Democratic margin
- D+28 in 1896MIT Election Lab
- Peak Republican margin
- R+47 in 1904MIT Election Lab
- Most similar
- Fluvanna County, VA · similarity 0.99
2024 results by precinct
2024 precinct map of Ada CountyPrecinct-level 2024 presidential results for Ada 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 | −41.4% |
| 1896 | +28.2% |
| 1900 | −12.9% |
| 1904 | −47.0% |
| 1908 | −11.7% |
| 1912 | −6.3% |
| 1916 | −0.8% |
| 1920 | −33.6% |
| 1924 | −37.5% |
| 1928 | −44.4% |
| 1932 | +4.5% |
| 1936 | +21.6% |
| 1940 | −1.9% |
| 1944 | −11.4% |
| 1948 | −13.9% |
| 1952 | −45.4% |
| 1956 | −39.9% |
| 1960 | −23.9% |
| 1964 | −12.8% |
| 1968 | −39.0% |
| 1972 | −44.1% |
| 1976 | −31.3% |
| 1980 | −39.1% |
| 1984 | −46.2% |
| 1988 | −28.0% |
| 1992 | −15.5% |
| 1996 | −15.9% |
| 2000 | −27.9% |
| 2004 | −23.3% |
| 2008 | −6.1% |
| 2012 | −11.3% |
| 2016 | −9.2% |
| 2020 | −3.9% |
| 2024 | −10.3% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| R | 116,116 | 143,759 | 267,416 | ||
| R | 120,539 | 130,699 | 259,700 | ||
| R | 75,677 | 93,752 | 195,626 | ||
| R | 77,137 | 97,554 | 180,546 | ||
| R | 82,236 | 93,328 | 180,760 | ||
| R | 58,523 | 94,641 | 155,030 | ||
| R | 40,650 | 75,050 | 123,485 | ||
| R | 43,040 | 61,811 | 117,743 | ||
| R | 31,941 | 49,000 | 110,166 | ||
| R | 30,525 | 54,951 | 87,334 | ||
| R | 21,760 | 60,036 | 82,924 | ||
| R | 21,324 | 55,205 | 86,544 | ||
| R | 21,125 | 41,135 | 63,889 | ||
| R | 12,687 | 36,665 | 54,311 | ||
| R | 11,529 | 30,185 | 47,881 | ||
| R | 19,639 | 25,404 | 45,043 | ||
| R | 17,017 | 27,703 | 44,720 | ||
| R | 11,328 | 26,387 | 37,715 | ||
| R | 10,281 | 27,415 | 37,736 | ||
| R | 11,253 | 14,972 | 26,705 | ||
| R | 10,667 | 13,410 | 24,144 | ||
| R | 12,381 | 12,861 | 25,293 | ||
| D | 12,027 | 7,581 | 20,574 | ||
| D | 8,836 | 8,055 | 17,522 | ||
| R | 3,921 | 10,279 | 14,308 | ||
| R | 2,255 | 7,220 | 13,255 | ||
| R | 4,173 | 8,419 | 12,619 | ||
| R | 5,207 | 5,299 | 10,966 | ||
| O | 2,569 | 3,198 | 9,994 | ||
| R | 3,721 | 4,778 | 9,002 | ||
| R | 1,466 | 4,536 | 6,525 | ||
| R | 2,072 | 2,706 | 4,931 | ||
| D | 1,531 | 851 | 2,409 | ||
| O | 0 | 1,170 | 2,827 | ||
| — | — | — | — | ||
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Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
English
19.8%
German
18.0%
Irish
11.4%
American
4.3%
Italian
4.2%
Scottish
3.0%
French
2.3%
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: 38.4 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
$91,502
Ada County ranks in the top 10% of US counties.
Ada County$91,502
Idaho$77,800
United States$80,734
Ada County ranks in the top 10% 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
8.3%
Child poverty is below the national average.
Children under 188.5%
Working age (18–64)8.3%
Seniors (65+)8.6%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
90.7%
speak English only
Spanish4.6%
Other Indo-European2.2%
Asian & Pacific Islander1.6%
Other languages1.0%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 52.5% of residents not counted as adherents by any reporting body.
Ada County anchors Idaho's Treasure Valley and has grown rapidly through in-migration, yet its 2024 presidential margin of R+10.3 suggests that newcomer growth has not flipped its partisan lean the way similar Sun Belt metros have.
Its margins are typically close. The Democratic margin reached twenty-eight points in 1896; the Republican margin reached forty-seven points in 1904. Between 2020 and 2024 the county moved six points toward the Republican candidate; the 2024 margin was ten points.
Its demographics sit near national norms: a 83% non-Hispanic-white share, a median household income of $91,502, and a 8% poverty rate. The county's voting pattern over the last decade is most similar to that of Fluvanna County and Lancaster 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.
Ada County, Idaho. Akashic. https://akashic.app/county/16001/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
More industrial catholic metro counties
Frequently asked questions
How did Ada County, Idaho vote in 2024?
In 2024, Ada County, Idaho voted Republican by 10.3 points (R+10), carried by the Republican candidate. Out of 267,416 votes cast, 116,116 went Democratic and 143,759 went Republican.
What is Ada County, Idaho's political typology?
Akashic places Ada County, Idaho in the "Industrial Catholic Metro" typology — Mid-size industrial metros with Catholic ethnic roots — among the most competitive, swing-prone ground in the country. 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 3 times, Republican 29 times, and other 2 times.
When did Ada County, Idaho last vote Democratic?
The most recent presidential election in which Ada County, Idaho voted Democratic was 1936.
How many people live in Ada County, Idaho?
Ada County, Idaho has a population of 518,935 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Ada County, Idaho?
Median household income in Ada County, Idaho is $91,502 — above the national median of $80,734. The Idaho state median is $77,800.
What is the political history of Ada County, Idaho?
Akashic tracks 38 presidential elections in Ada County, Idaho from 1876 to 2024. Of those, 3 went Democratic and 29 went Republican. The county's typology — "Industrial Catholic Metro" — captures where that record, its demographics, and its recent swing place it among American communities.