- Lead
- 1,361
- Total
- 17,973
- vs nation
- R+6.1
Iowa 40th State House District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 713
- Total
- 17,030
- vs nation
- R+8.6
- Lead
- 983
- Total
- 14,863
- vs nation
- R+8.7
- Lead
- 739
- Total
- 14,448
- vs nation
- R+9.0
- Lead
- 610
- Total
- 13,495
- vs nation
- R+11.8
- Lead
- 1,944
- Total
- 13,054
- vs nation
- R+12.4
- Lead
- 1,503
- Total
- 11,207
- vs nation
- R+13.9
- Lead
- 322
- Total
- 9,876
- vs nation
- R+11.8
Key facts
- 2024 presidential margin
- R+7.6MIT Election Lab
- Population
- 32,0362024 5-year
- Population density
- 866 / sq mi2024 5-year · TIGER/Line
- Land area
- 37 sq miTIGER/Line
- Median household income
- $85,5362024 5-year
- White (non-Hispanic)
- 83.9%2024 5-year
- Black
- 4.6%2024 5-year
- Hispanic / Latino
- 5.4%2024 5-year
- Peak Democratic margin
- D+14.3 in 1964MIT Election Lab
- Peak Republican margin
- R+69.3 in 1904MIT Election Lab
- Most similar
- State House District 91, IA · twin score 86.5
presidential history
Party record book
Iowa 40th State House 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
56.9%
3,882 votes · D+14.3 · modeled estimate
Runner-up · Michael Dukakis, 1988 · 49.3%
Republican
Theodore Roosevelt1904
80.1%
1,089 votes · R+69.3 · modeled estimate
Runner-up · Herbert Hoover, 1928 · 76.2%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Kamala Harris2024
8,152votes
45.4% of the vote · R+7.6 · modeled estimate
Runner-up · Joe Biden, 2020 · 7,951 votes
Republican
Donald Trump2024
9,513votes
52.9% of the vote · R+7.6 · modeled estimate
Runner-up · Donald Trump, 2020 · 8,664 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
+7.0pts D vs U.S.
Place R+0.7 · U.S. R+7.7 · modeled estimate
Runner-up · Walter Mondale, 1984 · +1.6 pts
Republican
Theodore Roosevelt1904
+49.6pts R vs U.S.
Place R+69.3 · U.S. R+19.7 · modeled estimate
Runner-up · William McKinley, 1900 · +42.3 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.
Iowa 40th State House District sits in the Corn Belt. In 2024 it voted Republican.
Across the recorded series it reached a Democratic high of 14.3 points in 1964 and a Republican high of 69.3 points in 1904. Between 2020 and 2024 the district moved 3.4 points toward the Republican candidate; the 2024 margin was 7.6 points.
A population of 32,036, a 84% non-Hispanic-white share, and a median household income of $85,536 describe the district. The district's voting pattern over the last decade is most similar to that of State House District 91 and State House District 17.
The state-house 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 40th State House District. Akashic. https://akashic.app/sld-lower/19040/. Accessed May 20, 2026. License: CC BY 4.0.