HarrisDemocratic31.0%119TrumpRepublican65.9%253OtherAll other candidates3.1%12
R+34.9- Lead
- 134
- Total
- 384
- vs nation
- R+33.4
modeled Census-place estimatemodeled estimate
Akashicstate senate district
South Dakota 18th State Senate District
Office (updates table and map)
President margin by year
Place winner margin
Boundary by 2024 margin · Precinct returns · VEST · MIT Election Lab
The precinct map shows the 2024 presidential vote; the timeline scrubs the district’s overall result across 1892–2024, on its current boundaries.
President results by year
Modeled candidate-vote estimate on current district boundaries
BidenDemocratic36.7%4,150TrumpRepublican60.5%6,831OtherAll other candidates2.8%315
R+23.7- Lead
- 2,681
- Total
- 11,296
- vs nation
- R+28.2
modeled Census-place estimatemodeled estimate
ClintonDemocratic34.4%3,444TrumpRepublican58.6%5,863OtherAll other candidates6.9%691
R+24.2- Lead
- 2,419
- Total
- 9,998
- vs nation
- R+26.3
modeled Census-place estimatemodeled estimate
ObamaDemocratic42.4%4,383RomneyRepublican55.1%5,701OtherAll other candidates2.5%255
R+12.7- Lead
- 1,318
- Total
- 10,339
- vs nation
- R+16.6
modeled Census-place estimatemodeled estimate
ObamaDemocratic47.8%5,041McCainRepublican49.8%5,257OtherAll other candidates2.5%259
R+2.0- Lead
- 216
- Total
- 10,557
- vs nation
- R+9.3
modeled Census-place estimatemodeled estimate
KerryDemocratic40.6%4,413BushRepublican57.6%6,261OtherAll other candidates1.8%193
R+17.0- Lead
- 1,848
- Total
- 10,867
- vs nation
- R+14.5
modeled Census-place estimatemodeled estimate
GoreDemocratic41.0%3,739BushRepublican56.3%5,131OtherAll other candidates2.7%242
R+15.3- Lead
- 1,392
- Total
- 9,112
- vs nation
- R+15.8
modeled Census-place estimatemodeled estimate
ClintonDemocratic42.6%3,932DoleRepublican44.2%4,086OtherAll other candidates13.2%1,220
R+1.7- Lead
- 154
- Total
- 9,238
- vs nation
- R+10.2
modeled Census-place estimatemodeled estimate
Key facts
- 2024 presidential margin
- R+34.9MIT Election Lab
- Population
- 24,1392024 5-year
- Population density
- 41 / sq mi2024 5-year · TIGER/Line
- Land area
- 593 sq miTIGER/Line
- Median household income
- $72,6602024 5-year
- White (non-Hispanic)
- 86.9%2024 5-year
- Black
- 1.3%2024 5-year
- Hispanic / Latino
- 5.2%2024 5-year
- Peak Democratic margin
- D+46.1 in 1932MIT Election Lab
- Peak Republican margin
- R+44.1 in 1904MIT Election Lab
- Most similar
- State Senate District 32, ND · twin score 91.4
presidential history
Party record book
South Dakota 18th State Senate District · the strongest Democratic and Republican presidential performances recorded here, measured three ways.
1892–2024 · 20 presidential cycles
Highest vote share
Largest share of the presidential candidate vote cast here.
Democratic
Woodrow Wilson1916
48.1%
1,500 votes · R+1.6 · modeled estimate
Runner-up · Barack Obama, 2008 · 47.8%
Republican
Theodore Roosevelt1904
70.5%
2,145 votes · R+44.1 · modeled estimate
Runner-up · Donald Trump, 2024 · 65.9%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Barack Obama2008
5,041votes
47.8% of the vote · R+2.0 · modeled estimate
Runner-up · John Kerry, 2004 · 4,413 votes
Republican
Donald Trump2020
6,831votes
60.5% of the vote · R+23.7 · modeled estimate
Runner-up · George W. Bush, 2004 · 6,261 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
Woodrow Wilson1912
+23.5pts D vs U.S.
Place D+43.1 · U.S. D+19.5 · a third-party candidate carried the Place · modeled estimate
Runner-up · Michael Dukakis, 1988 · +2.0 pts
Republican
Benjamin Harrison1892
+45.6pts R vs U.S.
Place R+43.9 · U.S. D+1.7 · modeled estimate
Runner-up · Donald Trump, 2024 · +33.4 pts
current representation
Current officeholders
RLauren NelsonState Senate · 18
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.
With a 2024 presidential margin of R+34.9, this sparsely populated district of roughly 24,000 residents reflects the heavily Republican rural voting patterns that define much of western South Dakota's political landscape.
Across the recorded series it reached a Democratic high of 46.1 points in 1932 and a Republican high of 44.1 points in 1904. Between 2020 and 2024 the district moved 11.2 points toward the Republican candidate; the 2024 margin was 34.9 points.
A population of 24,139, a 87% non-Hispanic-white share, and a median household income of $72,660 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 32 and State Senate District 14.
Political twins — state-senate districts
The state-senate districts whose fingerprint — 2000–2024 trajectory, demographics, ancestry, religion — sits closest to this one, and why.
State Senate District 32
North Dakota
91.4twin score
elasticitypopulation scale12-yr trend≠ median age
State Senate District 14
North Dakota
91.4twin score
population scaleelasticity% White≠ 2024 margin
State Senate District 8
South Dakota
90.3twin score
population scale2016–2020 trajectoryelasticity≠ % Catholic
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.
District research tools
Open the source-auditable district brief for electoral baseline, electorate, current-cycle coverage, geography, official dates, and methodology. Open campaign intelligence report → · Browse all comparisons →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
South Dakota 18th State Senate District. Akashic. https://akashic.app/sld-upper/46018/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
South Dakota at the ballot boxAll elections →
Places within South Dakota 18th State Senate District
counties it covers2
Frequently asked questions
How did South Dakota 18th State Senate District vote in 2024?
In 2024, South Dakota 18th State Senate District voted Republican by 34.9 points (R+34.9), carried by the Republican candidate. Out of 384 votes cast, 119 went Democratic and 253 went Republican.
When did South Dakota 18th State Senate District last vote Democratic?
The most recent presidential election in which South Dakota 18th State Senate District voted Democratic was 1964.
How many people live in South Dakota 18th State Senate District?
South Dakota 18th State Senate District has a population of 24,139 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in South Dakota 18th State Senate District?
Median household income in South Dakota 18th State Senate District is $72,660 — below the national median of $80,734. The South Dakota state median is $75,081.
What is the political history of South Dakota 18th State Senate District?
Akashic tracks 38 presidential elections in South Dakota 18th State Senate District from 1876 to 2024. Of those, 3 went Democratic and 29 went Republican.