- Lead
- 20,446
- Total
- 96,954
- vs nation
- D+22.6
Illinois 42nd State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 26,107
- Total
- 102,229
- vs nation
- D+21.1
- Lead
- 17,037
- Total
- 87,918
- vs nation
- D+17.3
- Lead
- 10,114
- Total
- 78,754
- vs nation
- D+9.0
- Lead
- 18,854
- Total
- 82,541
- vs nation
- D+15.6
- Lead
- 411
- Total
- 67,630
- vs nation
- D+3.1
- Lead
- 261
- Total
- 55,012
- vs nation
- R+1.0
- Lead
- 2,046
- Total
- 45,935
- vs nation
- R+4.1
Key facts
- 2024 presidential margin
- D+21.1MIT Election Lab
- Population
- 217,1582024 5-year
- Population density
- 2,473 / sq mi2024 5-year · TIGER/Line
- Land area
- 87.8 sq miTIGER/Line
- Median household income
- $109,8462024 5-year
- White (non-Hispanic)
- 54.4%2024 5-year
- Black
- 8.5%2024 5-year
- Hispanic / Latino
- 22.1%2024 5-year
- Peak Democratic margin
- D+25.5 in 2020MIT Election Lab
- Peak Republican margin
- R+62.4 in 1920MIT Election Lab
- Most similar
- State Senate District 31, IL · twin score 95.4
presidential history
Party record book
Illinois 42nd 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
Joe Biden2020
61.6%
62,949 votes · D+25.5 · modeled estimate
Runner-up · Barack Obama, 2008 · 60.7%
Republican
Warren G. Harding1920
79.3%
6,990 votes · R+62.4 · modeled estimate
Runner-up · Calvin Coolidge, 1924 · 71.9%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
62,949votes
61.6% of the vote · D+25.5 · modeled estimate
Runner-up · Kamala Harris, 2024 · 57,632 votes
Republican
Donald Trump2024
37,186votes
38.4% of the vote · D+21.1 · modeled estimate
Runner-up · Donald Trump, 2020 · 36,842 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
+22.6pts D vs U.S.
Place D+21.1 · U.S. R+1.5 · modeled estimate
Runner-up · Joe Biden, 2020 · +21.1 pts
Republican
Warren G. Harding1920
+36.2pts R vs U.S.
Place R+62.4 · U.S. R+26.2 · modeled estimate
Runner-up · Calvin Coolidge, 1924 · +35.4 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 | 54.4%53,600 | 45.6%44,997 | 98,597 |
| 2020 | D | 57.9%55,940 | 42.1%40,725 | 96,665 |
Illinois 42nd State Senate District sits in the Upper Midwest. In 2024 it voted Democratic.
Across the recorded series it reached a Democratic high of 25.5 points in 2020 and a Republican high of 62.4 points in 1920. Between 2020 and 2024 the district moved 4.4 points toward the Republican candidate; the 2024 margin was 21.1 points.
A population of 217,158, a 54% non-Hispanic-white share, and a median household income of $109,846 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 31 and State Senate District 23.
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 →
Illinois 42nd State Senate District. Akashic. https://akashic.app/sld-upper/17042/. Accessed May 20, 2026. License: CC BY 4.0.