- Lead
- 109
- Total
- 18,787
- vs nation
- D+0.9
Iowa 42nd State House District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 82
- Total
- 18,374
- vs nation
- R+4.0
- Lead
- 841
- Total
- 15,344
- vs nation
- R+7.6
- Lead
- 599
- Total
- 14,809
- vs nation
- R+7.9
- Lead
- 457
- Total
- 13,802
- vs nation
- R+10.6
- Lead
- 1,845
- Total
- 13,312
- vs nation
- R+11.4
- Lead
- 1,395
- Total
- 11,431
- vs nation
- R+12.7
- Lead
- 222
- Total
- 10,137
- vs nation
- R+10.7
Key facts
- 2024 presidential margin
- R+0.6MIT Election Lab
- Population
- 31,9112024 5-year
- Population density
- 2,020 / sq mi2024 5-year · TIGER/Line
- Land area
- 15.8 sq miTIGER/Line
- Median household income
- $102,6562024 5-year
- White (non-Hispanic)
- 87.1%2024 5-year
- Black
- 2.4%2024 5-year
- Hispanic / Latino
- 4.4%2024 5-year
- Peak Democratic margin
- D+15.7 in 1964MIT Election Lab
- Peak Republican margin
- R+62.8 in 1904MIT Election Lab
- Most similar
- State House District 43, IA · twin score 93.0
presidential history
Party record book
Iowa 42nd 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
57.5%
3,993 votes · D+15.7 · modeled estimate
Runner-up · Michael Dukakis, 1988 · 49.7%
Republican
Herbert Hoover1928
75.8%
3,310 votes · R+51.7 · modeled estimate
Runner-up · Theodore Roosevelt, 1904 · 74.0%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Kamala Harris2024
9,183votes
48.9% of the vote · R+0.6 · modeled estimate
Runner-up · Joe Biden, 2020 · 9,003 votes
Republican
Donald Trump2024
9,292votes
49.5% of the vote · R+0.6 · modeled estimate
Runner-up · Donald Trump, 2020 · 8,921 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
+8.1pts D vs U.S.
Place D+0.4 · U.S. R+7.7 · modeled estimate
Runner-up · Walter Mondale, 1984 · +2.7 pts
Republican
Theodore Roosevelt1904
+43.1pts R vs U.S.
Place R+62.8 · U.S. R+19.7 · modeled estimate
Runner-up · Herbert Hoover, 1932 · +39.9 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 of just 0.6 points, this 31,900-person district sits at the competitive edge of Iowa's legislative map, where small shifts in turnout can determine control of a seat.
Across the recorded series it reached a Democratic high of 15.7 points in 1964 and a Republican high of 62.8 points in 1904. Between 2020 and 2024 the district moved 1.0 points toward the Republican candidate; the 2024 margin was 0.6 points.
A population of 31,911, a 87% non-Hispanic-white share, and a median household income of $102,656 describe the district. The district's voting pattern over the last decade is most similar to that of State House District 43 and State House District 41.
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 42nd State House District. Akashic. https://akashic.app/sld-lower/19042/. Accessed May 20, 2026. License: CC BY 4.0.