- Lead
- 4,122
- Total
- 24,536
- vs nation
- D+18.3
Iowa 15th State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 6,021
- Total
- 26,783
- vs nation
- D+18.0
- Lead
- 5,078
- Total
- 24,806
- vs nation
- D+18.4
- Lead
- 5,910
- Total
- 24,604
- vs nation
- D+20.2
- Lead
- 5,529
- Total
- 23,018
- vs nation
- D+16.7
- Lead
- 3,201
- Total
- 21,518
- vs nation
- D+17.3
- Lead
- 2,875
- Total
- 18,567
- vs nation
- D+15.0
- Lead
- 3,997
- Total
- 16,751
- vs nation
- D+15.3
Key facts
- 2024 presidential margin
- D+16.8MIT Election Lab
- Population
- 63,7432024 5-year
- Population density
- 1,660 / sq mi2024 5-year · TIGER/Line
- Land area
- 38.4 sq miTIGER/Line
- Median household income
- $67,1762024 5-year
- White (non-Hispanic)
- 58.2%2024 5-year
- Black
- 9.0%2024 5-year
- Hispanic / Latino
- 19.9%2024 5-year
- Peak Democratic margin
- D+41.9 in 1964MIT Election Lab
- Peak Republican margin
- R+54.1 in 1904MIT Election Lab
- Most similar
- State Senate District 17, IA · twin score 95.4
presidential history
Party record book
Iowa 15th 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
70.7%
8,675 votes · D+41.9 · modeled estimate
Runner-up · Michael Dukakis, 1988 · 63.8%
Republican
Theodore Roosevelt1904
71.6%
1,347 votes · R+54.1 · modeled estimate
Runner-up · Herbert Hoover, 1928 · 63.5%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
16,112votes
60.2% of the vote · D+22.5 · modeled estimate
Runner-up · Barack Obama, 2012 · 15,032 votes
Republican
Donald Trump2020
10,091votes
37.7% of the vote · D+22.5 · modeled estimate
Runner-up · Donald Trump, 2024 · 10,021 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
+35.8pts D vs U.S.
Place D+28.1 · U.S. R+7.7 · modeled estimate
Runner-up · Walter Mondale, 1984 · +30.9 pts
Republican
Theodore Roosevelt1904
+34.5pts R vs U.S.
Place R+54.1 · U.S. R+19.7 · modeled estimate
Runner-up · Calvin Coolidge, 1924 · +21.2 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.
| Year | Vote lead | Democratic | Republican | Total |
|---|---|---|---|---|
| 2018 | D | 58.4%14,679 | 41.6%10,439 | 25,118 |
Iowa 15th State Senate District sits in the Corn Belt. In 2024 it voted Democratic.
Across the recorded series it reached a Democratic high of 41.9 points in 1964 and a Republican high of 54.1 points in 1904. Between 2020 and 2024 the district moved 5.7 points toward the Republican candidate; the 2024 margin was 16.8 points.
A population of 63,743, a 58% non-Hispanic-white share, and a median household income of $67,176 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 17 and State Senate District 65.
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 15th State Senate District. Akashic. https://akashic.app/sld-upper/19015/. Accessed May 20, 2026. License: CC BY 4.0.