Idaho 21st State Senate District · the strongest Democratic and Republican presidential performances recorded here, measured three ways.
1892–2024 · 34 presidential cycles
Highest vote share
Largest share of the presidential candidate vote cast here.
Democratic
Franklin D. Roosevelt1936
41.7%
799 votes · R+11.7 · modeled estimate
Runner-up · William J. Bryan, 1896 · 40.6%
Republican
Herbert Hoover1928
86.9%
1,390 votes · R+74.2 · modeled estimate
Runner-up · Dwight D. Eisenhower, 1952 · 83.8%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Kamala Harris2024
9,195votes
33.7% of the vote · R+29.9 · modeled estimate
Runner-up · Joe Biden, 2020 · 9,135 votes
Republican
Donald Trump2024
17,355votes
63.6% of the vote · R+29.9 · modeled estimate
Runner-up · Donald Trump, 2020 · 16,607 votes
Best relative to the U.S.
This Place’s margin against the national margin in the same election — positive when it leaned toward the party more than the country did.
Democratic
William J. Bryan1896
−12.7pts D vs U.S.
Place R+18.8 · U.S. R+6.1 · modeled estimate
Runner-up · Kamala Harris, 2024 · −28.4 pts
Republican
William H. Taft1912
+74.4pts R vs U.S.
Place R+54.9 · U.S. D+19.5 · modeled estimate
Runner-up · Barry Goldwater, 1964 · +65.7 pts
current representation
Current officeholders
RTreg BerntState Senate · 21
State legislative officeholder from OpenStates nightly current-legislator data.
U.S. House elections · 3 House
Senate and governor results are in the Office selector at the top of this page.
U.S. House
Each row is a county-allocated estimate of U.S. House votes for this district — county returns apportioned onto its boundary, not precinct-counted. “Vote lead” is the estimated local lead here, not necessarily the winner of the full contest.
Source · Akashic county-allocated estimate from certified county returns, House; not precinct-counted.
Year
Vote lead
Democratic
Republican
Total
2024
R
41.1%11,518
58.9%16,511
28,029
2020
R
43.7%10,974
56.3%14,162
25,136
2018
R
47.6%8,814
52.4%9,722
18,536
Idaho 21st State Senate District sits in the Northern Rockies. In 2024 it voted Republican.
Across the recorded series it reached a Republican high of 74.2 points in 1928. Between 2020 and 2024 the district moved 1.8 points toward the Republican candidate; the 2024 margin was 29.9 points.
A population of 53,066, a 81% non-Hispanic-white share, and a median household income of $88,486 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 20 and State Senate District 22.
Akashic
Political twins — state-senate districts
The state-senate districts whose fingerprint — 2000–2024 trajectory, demographics, ancestry, religion — sits closest to this one, and why.
Twin score (0–100) = weighted cosine between tier-standardized fingerprints: presidential margins 2000–2024 with 12-yr trend and elasticity, ACS income, age, education, population and race, top reported ancestries, and religious adherence — chips name the closest-shared dimensions and the widest gap. Re-weight the groups in the twins explorer.
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 → · Or open the source-auditable district brief for electoral baseline, electorate, current-cycle coverage, geography, official dates, and methodology. Open campaign intelligence report →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
Idaho 21st State Senate District. Akashic. https://akashic.app/sld-upper/16021/. Accessed May 20, 2026. License: CC BY 4.0.
How did Idaho 21st State Senate District vote in 2024?
In 2024, Idaho 21st State Senate District voted Republican by 29.9 points (R+29.9), carried by the Republican candidate. Out of 27,291 votes cast, 9,195 went Democratic and 17,355 went Republican.
How many people live in Idaho 21st State Senate District?
Idaho 21st State Senate District has a population of 53,066 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Idaho 21st State Senate District?
Median household income in Idaho 21st State Senate District is $88,486 — above the national median of $80,734. The Idaho state median is $77,800.
What is the political history of Idaho 21st State Senate District?
Akashic tracks 38 presidential elections in Idaho 21st State Senate District from 1876 to 2024. Of those, 0 went Democratic and 34 went Republican.