Idaho 18th State Senate District, Idaho: Tossup district. In 2024, voted R+10%. Republican peak: R+11 in 2012.
Key facts
- 2024 presidential margin
- R+10MIT Election Lab
- Political archetype
- TossupAkashic typology
- Population
- 51,9482024 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 Republican margin
- R+11 in 2012MIT Election Lab
Constituent county margins for State Senate District 18, IDOne cell per constituent county, colored by 2024 presidential margin from deep red (Republican) through neutral to deep blue (Democratic), ordered bluest first.
R+60D+60
One cell per constituent county. Ordered by 2024 D-vs-R margin (bluest first). Hover for county-level numbers.
5 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| R | 11,624 | 14,391 | 26,817 | ||
| R | 12,067 | 13,084 | 25,966 | ||
| R | 7,576 | 9,385 | 19,583 | ||
| R | 7,722 | 9,766 | 18,244 | ||
| R | 8,232 | 9,343 | 18,095 |
Demographics
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%
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.
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.
Median household income
2024 inflation-adjusted dollars
$91,502
State Senate District 18 ranks near the middle of US counties.
State Senate District 18$91,502
Idaho$77,800
United States$80,734
Source · American Community Survey 5-year estimates, 2024 release.
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.
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.
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.
Idaho Senate District 18 covers a dense slice of Ada County where the 2024 presidential margin reached D+22.8 — an outlier in a state that leans heavily Republican statewide, reflecting the district's younger, college-educated urban electorate.
The district's recent history is a story of close margins. the Republican margin reached eleven points in 2012. Most other elections have been decided by single-digit points.
Its demographics — a population of 51,948, a 83% non-Hispanic-white share, a median household income of $91,502 — situate the district close to national averages on several dimensions.
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
State Senate District 18, Idaho — The Long Memory. Akashic Intelligence — The Long Memory. https://tiers.akashic.app/sld-upper/16018/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
Frequently asked questions
How did State Senate District 18, Idaho vote in 2024?
In 2024, State Senate District 18, Idaho voted Republican by 10.3 points (R+10), carried by the Republican candidate. Out of 26,817 votes cast, 11,624 went Democratic and 14,391 went Republican.
What is State Senate District 18, Idaho's political archetype?
Akashic classifies State Senate District 18, Idaho as a "Tossup" district based on its long-arc presidential voting pattern. Across 5 elections in the dataset, the district has voted Democratic 0 times, Republican 5 times, and other 0 times.
How many people live in State Senate District 18, Idaho?
State Senate District 18, Idaho has a population of 51,948 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in State Senate District 18, Idaho?
Median household income in State Senate District 18, Idaho is $91,502 — above the national median of $80,734. The Idaho state median is $77,800.
What is the political history of State Senate District 18, Idaho?
Akashic tracks 5 presidential elections in State Senate District 18, Idaho from 2008 to 2024. Of those, 0 went Democratic and 5 went Republican. The district's archetype — "Tossup" — captures the overall trajectory of that voting record.