- Lead
- 12,097
- Total
- 57,550
- vs nation
- D+22.5
Illinois 42nd State House District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 14,691
- Total
- 60,744
- vs nation
- D+19.7
- Lead
- 10,117
- Total
- 54,379
- vs nation
- D+16.5
- Lead
- 2,946
- Total
- 49,748
- vs nation
- D+2.1
- Lead
- 8,090
- Total
- 52,189
- vs nation
- D+8.2
- Lead
- 2,360
- Total
- 49,676
- vs nation
- R+2.3
- Lead
- 3,834
- Total
- 44,784
- vs nation
- R+9.1
- Lead
- 2,542
- Total
- 40,460
- vs nation
- R+14.8
Key facts
- 2024 presidential margin
- D+21.0MIT Election Lab
- Population
- 108,6772024 5-year
- Population density
- 3,575 / sq mi2024 5-year · TIGER/Line
- Land area
- 30.4 sq miTIGER/Line
- Median household income
- $109,4432024 5-year
- White (non-Hispanic)
- 72.0%2024 5-year
- Black
- 4.6%2024 5-year
- Hispanic / Latino
- 8.7%2024 5-year
- Peak Democratic margin
- D+24.2 in 2020MIT Election Lab
- Peak Republican margin
- R+65.0 in 1920MIT Election Lab
- Most similar
- State House District 81, IL · twin score 98.9
presidential history
Party record book
Illinois 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
Joe Biden2020
60.6%
36,786 votes · D+24.2 · modeled estimate
Runner-up · Kamala Harris, 2024 · 58.5%
Republican
Warren G. Harding1920
80.3%
1,449 votes · R+65.0 · modeled estimate
Runner-up · Dwight D. Eisenhower, 1956 · 78.4%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
36,786votes
60.6% of the vote · D+24.2 · modeled estimate
Runner-up · Kamala Harris, 2024 · 33,693 votes
Republican
Ronald Reagan1984
26,702votes
73.7% of the vote · R+48.2 · modeled estimate
Runner-up · George W. Bush, 2004 · 25,749 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
Kamala Harris2024
+22.5pts D vs U.S.
Place D+21.0 · U.S. R+1.5 · modeled estimate
Runner-up · Joe Biden, 2020 · +19.7 pts
Republican
Thomas E. Dewey1948
+49.1pts R vs U.S.
Place R+44.6 · U.S. D+4.5 · modeled estimate
Runner-up · Wendell Willkie, 1940 · +42.0 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 | 56.2%29,618 | 43.8%23,037 | 52,655 |
| 2020 | D | 64.4%32,171 | 35.6%17,771 | 49,942 |
Illinois 42nd State House District sits in the Upper Midwest. In 2024 it voted Democratic.
Across the recorded series it reached a Democratic high of 24.2 points in 2020 and a Republican high of 65.0 points in 1920. Between 2020 and 2024 the district moved 3.2 points toward the Republican candidate; the 2024 margin was 21.0 points.
A population of 108,677, a 72% non-Hispanic-white share, and a median household income of $109,443 describe the district. The district's voting pattern over the last decade is most similar to that of State House District 81 and State House District 45.
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 42nd State House District. Akashic. https://akashic.app/sld-lower/17042/. Accessed May 20, 2026. License: CC BY 4.0.