- Lead
- 151,548
- Total
- 381,466
- vs nation
- R+38.3
Illinois 15th Congressional District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 153,152
- Total
- 396,028
- vs nation
- R+43.1
- Lead
- 142,327
- Total
- 371,616
- vs nation
- R+40.4
- Lead
- 86,356
- Total
- 355,374
- vs nation
- R+28.2
- Lead
- 42,701
- Total
- 370,873
- vs nation
- R+18.8
- Lead
- 90,801
- Total
- 375,305
- vs nation
- R+21.7
- Lead
- 55,696
- Total
- 349,708
- vs nation
- R+16.4
- Lead
- 9,228
- Total
- 333,649
- vs nation
- R+11.3
Key facts
- 2024 presidential margin
- R+39.7MIT Election Lab
- Population
- 753,5162024 5-year
- Population density
- 45 / sq mi2024 5-year · TIGER/Line
- Land area
- 16,753 sq miTIGER/Line
- Median household income
- $73,9932024 5-year
- White (non-Hispanic)
- 89.7%2024 5-year
- Black
- 2.9%2024 5-year
- Hispanic / Latino
- 2.8%2024 5-year
- Peak Democratic margin
- D+18.7 in 1912MIT Election Lab
- Peak Republican margin
- R+39.7 in 2024MIT Election Lab
- Most similar
- Congressional District 12, IL · twin score 98.5
presidential history
Party record book
Illinois 15th Congressional 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
Franklin D. Roosevelt1932
57.8%
207,769 votes · D+17.3 · modeled estimate
Runner-up · Lyndon B. Johnson, 1964 · 55.4%
Republican
Donald Trump2024
69.0%
263,049 votes · R+39.7 · modeled estimate
Runner-up · Donald Trump, 2020 · 68.2%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Franklin D. Roosevelt1936
208,973votes
52.8% of the vote · D+7.4 · modeled estimate
Runner-up · Franklin D. Roosevelt, 1932 · 207,769 votes
Republican
Donald Trump2020
270,125votes
68.2% of the vote · R+38.7 · modeled estimate
Runner-up · Donald Trump, 2024 · 263,049 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
William J. Bryan1900
+7.2pts D vs U.S.
Place R+0.3 · U.S. R+7.5 · modeled estimate
Runner-up · John W. Davis, 1924 · +6.7 pts
Republican
Donald Trump2020
+43.1pts R vs U.S.
Place R+38.7 · U.S. D+4.5 · modeled estimate
Runner-up · Donald Trump, 2016 · +40.4 pts
Current officeholders
Federal officeholders only. State and local officeholders are planned for the next data pass.
Senate and governor results are in the Office selector at the top of this page.
U.S. House
Each result reflects the U.S. House district as it was drawn for that election; redistricting has redrawn these lines over time, so they can differ from the current 120th-Congress district shown on the map above.
Illinois' 15th spans a vast swath of rural downstate territory where Republican presidential candidates have carried the district by margins exceeding 40 points in recent cycles, making it among the most lopsided congressional districts in the region.
Across the recorded series it reached a Democratic high of 18.7 points in 1912 and a Republican high of 39.7 points in 2024. Between 2020 and 2024 the district moved 1.1 points toward the Republican candidate; the 2024 margin was 39.7 points.
A population of 753,516, a 90% non-Hispanic-white share, and a median household income of $73,993 describe the district. The district's voting pattern over the last decade is most similar to that of Congressional District 12 and Congressional District 8.
The congressional 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 15th Congressional District. Akashic. https://akashic.app/cd/1715/. Accessed May 20, 2026. License: CC BY 4.0.