Illinois 15th 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
Barack Obama2008
78.7%
78,288 votes · D+57.9 · modeled estimate
Runner-up · Barack Obama, 2012 · 76.3%
Republican
Warren G. Harding1920
64.9%
18,679 votes · R+33.4 · modeled estimate
Runner-up · Calvin Coolidge, 1924 · 55.3%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Barack Obama2008
78,288votes
78.7% of the vote · D+57.9 · modeled estimate
Runner-up · Joe Biden, 2020 · 77,883 votes
Republican
Richard Nixon1972
38,162votes
43.6% of the vote · D+12.5 · modeled estimate
Runner-up · Dwight D. Eisenhower, 1956 · 38,064 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
+53.0pts D vs U.S.
Place D+55.1 · U.S. D+2.1 · modeled estimate
Runner-up · Barack Obama, 2008 · +50.6 pts
Republican
Warren G. Harding1920
+7.2pts R vs U.S.
Place R+33.4 · U.S. R+26.2 · modeled estimate
Runner-up · Calvin Coolidge, 1924 · +1.4 pts
current representation
Current officeholders
DNapoleon HarrisState Senate · 15
State legislative officeholder from OpenStates nightly current-legislator data.
U.S. House elections · 1 House
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.
Source · Akashic county-allocated estimate from certified county returns, House; not precinct-counted.
Year
Vote lead
Democratic
Republican
Total
2024
D
68.5%58,499
31.5%26,930
85,429
Illinois 15th State Senate District sits in the Upper Midwest. In 2024 it voted Democratic.
Across the recorded series it reached a Democratic high of 57.9 points in 2008 and a Republican high of 33.4 points in 1920. Between 2020 and 2024 the district moved 7.2 points toward the Republican candidate; the 2024 margin was 46.3 points.
A population of 217,045, a 28% non-Hispanic-white share, and a median household income of $70,641 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 17 and State Senate District 4.
Akashic
Political twins — state-senate districts
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.
Compare two places, side by side
Twelve curated comparisons line up election history, demographics, and the divergence story for two places at a glance. Browse all comparisons → · Or open the source-auditable district brief for electoral baseline, electorate, current-cycle coverage, geography, official dates, and methodology. Open campaign intelligence report →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
Illinois 15th State Senate District. Akashic. https://akashic.app/sld-upper/17015/. Accessed May 20, 2026. License: CC BY 4.0.
How did Illinois 15th State Senate District vote in 2024?
In 2024, Illinois 15th State Senate District voted Democratic by 46.3 points (D+46.3), carried by the Democratic candidate. Out of 92,012 votes cast, 66,299 went Democratic and 23,692 went Republican.
When did Illinois 15th State Senate District last vote Republican?
The most recent presidential election in which Illinois 15th State Senate District voted Republican was 1924.
How many people live in Illinois 15th State Senate District?
Illinois 15th State Senate District has a population of 217,045 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Illinois 15th State Senate District?
Median household income in Illinois 15th State Senate District is $70,641 — below the national median of $80,734. The Illinois state median is $83,390.
What is the political history of Illinois 15th State Senate District?
Akashic tracks 38 presidential elections in Illinois 15th State Senate District from 1876 to 2024. Of those, 32 went Democratic and 5 went Republican.