South Dakota 18th State Senate District, South Dakota: Republican loyalist district. In 2024, voted R+23%. Democratic peak: D+46 in 1932.
Key facts
- 2024 presidential margin
- R+23MIT Election Lab
- Political archetype
- Republican loyalistAkashic typology
- Population
- 26,0232024 5-year
- Median household income
- $71,2142024 5-year
- White (non-Hispanic)
- 87.5%2024 5-year
- Black
- 1.6%2024 5-year
- Hispanic / Latino
- 5.6%2024 5-year
- Peak Democratic margin
- D+46 in 1932MIT Election Lab
- Peak Republican margin
- R+44 in 1904MIT Election Lab
Constituent county margins for State Senate District 18, SDOne 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.
38 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| R | 4,388 | 7,090 | 11,801 | ||
| R | 4,545 | 7,001 | 11,876 | ||
| R | 3,748 | 6,020 | 10,491 | ||
| R | 4,733 | 5,862 | 10,870 | ||
| D | 5,491 | 5,432 | 11,204 | ||
| R | 4,806 | 6,464 | 11,482 | ||
| D | 5,309 | 4,048 | 9,615 | ||
| D | 4,286 | 4,229 | 9,781 | ||
| D | 3,889 | 3,750 | 10,407 | ||
| R | 4,267 | 4,581 | 8,934 | ||
| R | 3,397 | 5,685 | 9,141 | ||
| R | 3,088 | 5,870 | 9,830 | ||
| R | 4,431 | 4,483 | 8,996 | ||
| R | 4,319 | 4,797 | 9,142 | ||
| R | 3,077 | 4,362 | 7,844 | ||
| D | 4,193 | 3,517 | 7,709 | ||
| R | 3,383 | 4,540 | 7,923 | ||
| R | 3,317 | 4,514 | 7,832 | ||
| R | 2,462 | 5,368 | 7,830 | ||
| D | 3,289 | 3,286 | 6,641 | ||
| R | 2,667 | 3,651 | 6,318 | ||
| R | 3,453 | 4,601 | 8,054 | ||
| D | 4,875 | 2,992 | 8,301 | ||
| D | 5,451 | 1,953 | 7,523 | ||
| R | 3,093 | 3,412 | 6,535 | ||
| O | 777 | 1,747 | 4,355 | ||
| R | 1,303 | 2,878 | 4,656 | ||
| R | 1,600 | 1,645 | 3,322 | ||
| O | 1,448 | 0 | 3,317 | ||
| R | 1,256 | 1,865 | 3,263 | ||
| R | 850 | 2,264 | 3,233 | ||
| R | 1,446 | 1,877 | 3,362 | ||
| R | 1,512 | 1,635 | 3,167 | ||
| R | 256 | 1,323 | 2,453 | ||
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Demographics
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
35.8%
Irish
10.3%
English
7.4%
American
2.5%
French
2.4%
Italian
1.4%
Polish
1.3%
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: 40.7 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
$71,214
State Senate District 18 ranks near the middle of US counties.
State Senate District 18$71,214
South Dakota$75,081
United States$80,734
Source · American Community Survey 5-year estimates, 2024 release.
Poverty rate
All persons below federal poverty line
12.7%
Children face moderate poverty.
Children under 1815.5%
Working age (18–64)11.7%
Seniors (65+)12.9%
Source · American Community Survey 5-year estimates, 2024 release.
Language at home
Population aged 5 and older
94.5%
speak English only
Spanish3.5%
Other Indo-European1.3%
Other languages0.5%
Asian & Pacific Islander0.3%
Source · ACS 5-year estimates, 2024.
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 42.9% of residents not counted as adherents by any reporting body.
With a 2024 presidential margin of R+34.9, this sparsely populated district of roughly 24,000 residents reflects the deep-red rural voting patterns that define much of western South Dakota's political landscape.
The Republican margin in South Dakota 18th State Senate District reached its widest at forty-four points in 1904. The margin in 2024 was twenty-three points, in line with the district's deep historical pattern.
Its loyalty is rooted in its place. Median household income of $71,214, a 88% non-Hispanic-white share, and a population of 26,023 together describe a district whose political habits are deeply settled.
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.
State Senate District 18, South Dakota. Akashic. https://akashic.app/sld-upper/46018/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
Frequently asked questions
How did State Senate District 18, South Dakota vote in 2024?
In 2024, State Senate District 18, South Dakota voted Republican by 22.9 points (R+23), carried by the Republican candidate. Out of 11,801 votes cast, 4,388 went Democratic and 7,090 went Republican.
What is State Senate District 18, South Dakota's political archetype?
Akashic classifies State Senate District 18, South Dakota as a "Republican loyalist" district based on its long-arc presidential voting pattern. Across 38 elections in the dataset, the district has voted Democratic 8 times, Republican 24 times, and other 2 times.
When did State Senate District 18, South Dakota last vote Democratic?
The most recent presidential election in which State Senate District 18, South Dakota voted Democratic was 2008.
How many people live in State Senate District 18, South Dakota?
State Senate District 18, South Dakota has a population of 26,023 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, South Dakota?
Median household income in State Senate District 18, South Dakota is $71,214 — below the national median of $80,734. The South Dakota state median is $75,081.
What is the political history of State Senate District 18, South Dakota?
Akashic tracks 38 presidential elections in State Senate District 18, South Dakota from 1876 to 2024. Of those, 8 went Democratic and 24 went Republican. The district's archetype — "Republican loyalist" — captures the overall trajectory of that voting record.