- Lead
- 25,224
- Total
- 39,702
- vs nation
- D+65.0
Illinois 40th State House District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 30,434
- Total
- 44,399
- vs nation
- D+64.1
- Lead
- 26,776
- Total
- 38,367
- vs nation
- D+67.7
- Lead
- 24,040
- Total
- 34,605
- vs nation
- D+65.6
- Lead
- 26,960
- Total
- 37,280
- vs nation
- D+65.0
- Lead
- 21,955
- Total
- 34,279
- vs nation
- D+66.5
- Lead
- 19,449
- Total
- 31,521
- vs nation
- D+61.2
- Lead
- 17,884
- Total
- 29,466
- vs nation
- D+52.2
Key facts
- 2024 presidential margin
- D+63.5MIT Election Lab
- Population
- 108,6602024 5-year
- Population density
- 19,404 / sq mi2024 5-year · TIGER/Line
- Land area
- 5.6 sq miTIGER/Line
- Median household income
- $94,7722024 5-year
- White (non-Hispanic)
- 37.7%2024 5-year
- Black
- 4.2%2024 5-year
- Hispanic / Latino
- 45.6%2024 5-year
- Peak Democratic margin
- D+72.3 in 2008MIT Election Lab
- Peak Republican margin
- R+21.6 in 1920MIT Election Lab
- Most similar
- State House District 39, IL · twin score 97.9
presidential history
Party record book
Illinois 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
Barack Obama2008
85.2%
31,745 votes · D+72.3 · modeled estimate
Runner-up · Barack Obama, 2012 · 83.5%
Republican
Warren G. Harding1920
54.2%
6,373 votes · R+21.6 · modeled estimate
Runner-up · Calvin Coolidge, 1924 · 44.8%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
36,782votes
82.8% of the vote · D+68.5 · modeled estimate
Runner-up · Kamala Harris, 2024 · 31,997 votes
Republican
Dwight D. Eisenhower1956
12,893votes
40.4% of the vote · D+19.1 · modeled estimate
Runner-up · Richard Nixon, 1972 · 12,217 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
Hillary Clinton2016
+67.7pts D vs U.S.
Place D+69.8 · U.S. D+2.1 · modeled estimate
Runner-up · John Kerry, 2004 · +66.5 pts
Republican
William H. Taft1912
−0.2pts R vs U.S.
Place D+19.8 · U.S. D+19.5 · a third-party candidate carried the Place · modeled estimate
Runner-up · Warren G. Harding, 1920 · −4.6 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 |
|---|---|---|---|---|
| 2024 | D | 73.1%30,478 | 26.9%11,197 | 41,675 |
Illinois 40th State House District sits in the Upper Midwest. In 2024 it voted Democratic.
Across the recorded series it reached a Democratic high of 72.3 points in 2008 and a Republican high of 21.6 points in 1920. Between 2020 and 2024 the district moved 5.0 points toward the Republican candidate; the 2024 margin was 63.5 points.
A population of 108,660, a 38% non-Hispanic-white share, and a median household income of $94,772 describe the district. The district's voting pattern over the last decade is most similar to that of State House District 39 and State House District 4.
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 →
Illinois 40th State House District. Akashic. https://akashic.app/sld-lower/17040/. Accessed May 20, 2026. License: CC BY 4.0.