- Lead
- 15,320
- Total
- 34,051
- vs nation
- D+46.5
Iowa 18th State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 16,621
- Total
- 36,256
- vs nation
- D+41.4
- Lead
- 13,254
- Total
- 33,807
- vs nation
- D+37.1
- Lead
- 14,641
- Total
- 33,365
- vs nation
- D+40.0
- Lead
- 13,847
- Total
- 31,413
- vs nation
- D+36.8
- Lead
- 10,355
- Total
- 28,569
- vs nation
- D+38.7
- Lead
- 8,955
- Total
- 24,725
- vs nation
- D+35.7
- Lead
- 9,701
- Total
- 22,817
- vs nation
- D+34.0
Key facts
- 2024 presidential margin
- D+45.0MIT Election Lab
- Population
- 63,9782024 5-year
- Population density
- 3,281 / sq mi2024 5-year · TIGER/Line
- Land area
- 19.5 sq miTIGER/Line
- Median household income
- $73,3122024 5-year
- White (non-Hispanic)
- 72.9%2024 5-year
- Black
- 9.4%2024 5-year
- Hispanic / Latino
- 7.0%2024 5-year
- Peak Democratic margin
- D+58.9 in 1964MIT Election Lab
- Peak Republican margin
- R+31.6 in 1924MIT Election Lab
- Most similar
- State Senate District 64, MN · twin score 93.0
presidential history
Party record book
Iowa 18th State Senate District · the strongest Democratic and Republican presidential performances recorded here, measured three ways.
1892–2024 (partial returns from 1876) · 38 presidential cycles · 38 with a vote-share denominator · 34 with a national benchmark
Highest vote share
Largest share of the presidential candidate vote cast here.
Democratic
Lyndon B. Johnson1964
79.2%
13,635 votes · D+58.9 · modeled estimate
Runner-up · Michael Dukakis, 1988 · 73.6%
Republican
Theodore Roosevelt1904
55.1%
1,325 votes · R+28.4 · modeled estimate
Runner-up · Herbert Hoover, 1928 · 52.2%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
26,040votes
71.8% of the vote · D+45.8 · modeled estimate
Runner-up · Kamala Harris, 2024 · 24,386 votes
Republican
Donald Trump2020
9,419votes
26.0% of the vote · D+45.8 · modeled estimate
Runner-up · Donald Trump, 2024 · 9,066 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
Michael Dukakis1988
+55.6pts D vs U.S.
Place D+47.8 · U.S. R+7.7 · modeled estimate
Runner-up · Walter Mondale, 1984 · +52.6 pts
Republican
Theodore Roosevelt1904
+8.7pts R vs U.S.
Place R+28.4 · U.S. R+19.7 · modeled estimate
Runner-up · Calvin Coolidge, 1924 · +6.4 pts
Current officeholders
State legislative officeholder from OpenStates nightly current-legislator data.
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 exceeding 40 points, this rural district ranks among Iowa's most heavily one-sided, reflecting the broad realignment of small-town and agricultural communities that has reshaped the state's electoral map over the past decade.
Across the recorded series it reached a Democratic high of 58.9 points in 1964 and a Republican high of 31.6 points in 1924. Between 2020 and 2024 the district moved 0.9 points toward the Republican candidate; the 2024 margin was 45.0 points.
A population of 63,978, a 73% non-Hispanic-white share, and a median household income of $73,312 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 64 and State Senate District 28.
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.
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 →
Iowa 18th State Senate District. Akashic. https://akashic.app/sld-upper/19018/. Accessed May 20, 2026. License: CC BY 4.0.