Jefferson County, Idaho: Sunbelt Conservative county. In 2024, voted R+73%. Republican peak: R+77 in 1984.
Key facts
- 2024 presidential margin
- R+73MIT Election Lab
- Political typology
- Sunbelt ConservativeAkashic typology
- Population
- 33,1542024 5-year
- Median household income
- $86,6792024 5-year
- White (non-Hispanic)
- 87.5%2024 5-year
- Black
- 0.1%2024 5-year
- Hispanic / Latino
- 11.0%2024 5-year
- Peak Democratic margin
- D+45 in 1936MIT Election Lab
- Peak Republican margin
- R+77 in 1984MIT Election Lab
- Most similar
- Cassia County, ID · similarity 1.00
2024 results by precinct
2024 precinct map of Jefferson CountyPrecinct-level 2024 presidential results for Jefferson 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 | No data |
| 1896 | No data |
| 1900 | No data |
| 1904 | No data |
| 1908 | No data |
| 1912 | No data |
| 1916 | +22.5% |
| 1920 | −41.5% |
| 1924 | −39.1% |
| 1928 | −10.6% |
| 1932 | +35.5% |
| 1936 | +45.0% |
| 1940 | +20.9% |
| 1944 | +20.2% |
| 1948 | +14.8% |
| 1952 | −33.6% |
| 1956 | −20.2% |
| 1960 | −5.0% |
| 1964 | −14.1% |
| 1968 | −41.4% |
| 1972 | −44.4% |
| 1976 | −33.6% |
| 1980 | −72.5% |
| 1984 | −76.6% |
| 1988 | −61.6% |
| 1992 | −35.0% |
| 1996 | −47.3% |
| 2000 | −68.7% |
| 2004 | −74.3% |
| 2008 | −66.1% |
| 2012 | −75.5% |
| 2016 | −65.0% |
| 2020 | −73.6% |
| 2024 | −73.3% |
DemocraticRepublican
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| R | 1,891 | 13,481 | 15,819 | ||
| R | 1,661 | 12,099 | 14,173 | ||
| R | 976 | 8,436 | 11,471 | ||
| R | 1,303 | 9,895 | 11,381 | ||
| R | 1,641 | 8,540 | 10,441 | ||
| R | 1,084 | 7,703 | 8,906 | ||
| R | 1,100 | 6,480 | 7,836 | ||
| R | 1,427 | 4,925 | 7,403 | ||
| R | 978 | 3,471 | 7,116 | ||
| R | 1,198 | 5,295 | 6,649 | ||
| R | 743 | 5,770 | 6,563 | ||
| R | 833 | 5,860 | 6,933 | ||
| R | 1,745 | 3,599 | 5,525 | ||
| R | 715 | 2,983 | 5,110 | ||
| R | 955 | 2,927 | 4,761 | ||
| R | 2,061 | 2,740 | 4,801 | ||
| R | 2,374 | 2,625 | 4,999 | ||
| R | 1,823 | 2,748 | 4,571 | ||
| R | 1,474 | 2,970 | 4,446 | ||
| D | 2,017 | 1,490 | 3,568 | ||
| D | 2,198 | 1,458 | 3,665 | ||
| D | 2,631 | 1,717 | 4,364 | ||
| D | 2,776 | 1,037 | 3,864 | ||
| D | 2,501 | 1,177 | 3,732 | ||
| R | 1,350 | 1,671 | 3,028 | ||
| R | 305 | 1,393 | 2,782 | ||
| R | 741 | 1,794 | 2,535 | ||
| D | 1,606 | 993 | 2,725 | ||
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Demographics
2024 ACS
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
English
32.7%
German
12.7%
American
5.5%
Irish
5.0%
Scottish
5.0%
French
2.5%
Italian
2.3%
Sample size too small to break out by ancestry reliably.
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: 32.8 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
$86,679
Jefferson County ranks in the top 10% of US counties.
Jefferson County$86,679
Idaho$77,800
United States$80,734
Jefferson 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
9.7%
Child poverty is below the national average.
Children under 1812.3%
Working age (18–64)7.7%
Seniors (65+)18.9%
Source · American Community Survey 5-year estimates, 2024 release.
2024 ACS
Language at home
Population aged 5 and older
88.4%
speak English only
Spanish10.0%
Other Indo-European1.0%
Asian & Pacific Islander0.5%
Other languages0.1%
Source · ACS 5-year estimates, 2024.
2020 religion census
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 11.7% of residents not counted as adherents by any reporting body.
Jefferson County's 2024 presidential margin of R+73.2 ranks among the widest in the state, reflecting a predominantly rural, agricultural population with little urban counterweight to the region's strong Republican lean.
The Republican margin here reached seventy-seven points in 1984. The 2024 margin was seventy-three points.
A median household income of $86,679, a 88% non-Hispanic-white share, and a population of 33,154 describe the county. The county's voting pattern over the last decade is most similar to that of Cassia County and Sevier 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.
Jefferson County, Idaho. Akashic. https://akashic.app/county/16051/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
More sunbelt conservative counties
Frequently asked questions
How did Jefferson County, Idaho vote in 2024?
In 2024, Jefferson County, Idaho voted Republican by 73.3 points (R+73), carried by the Republican candidate. Out of 15,819 votes cast, 1,891 went Democratic and 13,481 went Republican.
What is Jefferson County, Idaho's political typology?
Akashic places Jefferson County, Idaho in the "Sunbelt Conservative" typology — Affluent, predominantly white Sunbelt counties — reliably Republican. 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 6 times, Republican 22 times, and other 0 times.
When did Jefferson County, Idaho last vote Democratic?
The most recent presidential election in which Jefferson County, Idaho voted Democratic was 1948.
How many people live in Jefferson County, Idaho?
Jefferson County, Idaho has a population of 33,154 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Jefferson County, Idaho?
Median household income in Jefferson County, Idaho is $86,679 — above the national median of $80,734. The Idaho state median is $77,800.
What is the political history of Jefferson County, Idaho?
Akashic tracks 38 presidential elections in Jefferson County, Idaho from 1876 to 2024. Of those, 6 went Democratic and 22 went Republican. The county's typology — "Sunbelt Conservative" — captures where that record, its demographics, and its recent swing place it among American communities.