- Lead
- 11,623
- Total
- 28,729
- vs nation
- R+39.0
Iowa 13th State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 10,044
- Total
- 29,887
- vs nation
- R+38.1
- Lead
- 8,510
- Total
- 28,925
- vs nation
- R+31.5
- Lead
- 769
- Total
- 29,200
- vs nation
- R+1.2
- Lead
- 1,498
- Total
- 29,401
- vs nation
- R+2.2
- Lead
- 837
- Total
- 30,613
- vs nation
- D+5.2
- Lead
- 1,235
- Total
- 27,893
- vs nation
- D+3.9
- Lead
- 5,169
- Total
- 27,299
- vs nation
- D+10.4
Key facts
- 2024 presidential margin
- R+40.5MIT Election Lab
- Population
- 63,7402024 5-year
- Population density
- 36 / sq mi2024 5-year · TIGER/Line
- Land area
- 1,777 sq miTIGER/Line
- Median household income
- $63,9472024 5-year
- White (non-Hispanic)
- 84.9%2024 5-year
- Black
- 2.3%2024 5-year
- Hispanic / Latino
- 7.5%2024 5-year
- Peak Democratic margin
- D+37.5 in 1964MIT Election Lab
- Peak Republican margin
- R+40.5 in 2024MIT Election Lab
- Most similar
- State Senate District 48, IA · twin score 95.7
presidential history
Party record book
Iowa 13th 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
68.6%
24,764 votes · D+37.5 · modeled estimate
Runner-up · Michael Dukakis, 1988 · 61.5%
Republican
Donald Trump2024
69.5%
19,975 votes · R+40.5 · modeled estimate
Runner-up · Donald Trump, 2020 · 66.0%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Franklin D. Roosevelt1940
24,935votes
54.1% of the vote · D+8.8 · modeled estimate
Runner-up · Lyndon B. Johnson, 1964 · 24,764 votes
Republican
Herbert Hoover1928
25,144votes
63.8% of the vote · R+27.5 · modeled estimate
Runner-up · Warren G. Harding, 1920 · 23,449 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
+31.8pts D vs U.S.
Place D+24.1 · U.S. R+7.7 · modeled estimate
Runner-up · Walter Mondale, 1984 · +30.5 pts
Republican
Donald Trump2024
+39.0pts R vs U.S.
Place R+40.5 · U.S. R+1.5 · modeled estimate
Runner-up · Donald Trump, 2020 · +38.1 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.
The district recorded a Republican presidential margin of R+40.5 in 2024 and D+5.1 in 2008, switching sides at least once in between. About 61,900 residents lived here, with White alone at 85.9% in the 2024 ACS 5-year.
Across the recorded series it reached a Democratic high of 37.5 points in 1964 and a Republican high of 40.5 points in 2024. Between 2020 and 2024 the district moved 6.9 points toward the Republican candidate; the 2024 margin was 40.5 points.
A population of 63,740, a 85% non-Hispanic-white share, and a median household income of $63,947 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 48 and State Senate District 44.
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 13th State Senate District. Akashic. https://akashic.app/sld-upper/19013/. Accessed May 20, 2026. License: CC BY 4.0.