- Lead
- 24,895
- Total
- 111,812
- vs nation
- R+20.8
Illinois 45th State Senate District
President margin by year
Place winner margin
President results by year
Modeled candidate-vote estimate on current district boundaries
- Lead
- 23,136
- Total
- 115,825
- vs nation
- R+24.4
- Lead
- 22,026
- Total
- 104,883
- vs nation
- R+23.1
- Lead
- 11,550
- Total
- 103,735
- vs nation
- R+15.0
- Lead
- 3,529
- Total
- 107,860
- vs nation
- R+10.5
- Lead
- 21,603
- Total
- 106,706
- vs nation
- R+17.8
- Lead
- 18,229
- Total
- 93,867
- vs nation
- R+19.9
- Lead
- 11,194
- Total
- 86,002
- vs nation
- R+21.5
Key facts
- 2024 presidential margin
- R+22.3MIT Election Lab
- Population
- 217,0912024 5-year
- Population density
- 76 / sq mi2024 5-year · TIGER/Line
- Land area
- 2,863 sq miTIGER/Line
- Median household income
- $78,4092024 5-year
- White (non-Hispanic)
- 84.8%2024 5-year
- Black
- 3.7%2024 5-year
- Hispanic / Latino
- 6.1%2024 5-year
- Peak Democratic margin
- D+6.6 in 1912MIT Election Lab
- Peak Republican margin
- R+65.8 in 1920MIT Election Lab
- Most similar
- State Senate District 37, IL · twin score 91.2
presidential history
Party record book
Illinois 45th 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
47.3%
51,050 votes · R+3.3 · modeled estimate
Runner-up · Lyndon B. Johnson, 1964 · 46.2%
Republican
Warren G. Harding1920
81.1%
38,062 votes · R+65.8 · modeled estimate
Runner-up · Herbert Hoover, 1928 · 75.1%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Barack Obama2008
51,050votes
47.3% of the vote · R+3.3 · modeled estimate
Runner-up · Barack Obama, 2012 · 44,944 votes
Republican
Donald Trump2020
67,975votes
58.7% of the vote · R+20.0 · modeled estimate
Runner-up · Donald Trump, 2024 · 67,495 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
Barack Obama2008
−10.5pts D vs U.S.
Place R+3.3 · U.S. D+7.3 · modeled estimate
Runner-up · Woodrow Wilson, 1912 · −12.9 pts
Republican
Wendell Willkie1940
+39.8pts R vs U.S.
Place R+29.9 · U.S. D+9.9 · modeled estimate
Runner-up · Warren G. Harding, 1920 · +39.6 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 | R | 25.6%22,888 | 74.4%66,559 | 89,447 |
| 2020 | R | 42.3%44,152 | 57.7%60,161 | 104,313 |
Illinois 45th State Senate District sits in the Upper Midwest. In 2024 it voted Republican.
Across the recorded series it reached a Democratic high of 6.6 points in 1912 and a Republican high of 65.8 points in 1920. Between 2020 and 2024 the district moved 2.3 points toward the Republican candidate; the 2024 margin was 22.3 points.
A population of 217,091, a 85% non-Hispanic-white share, and a median household income of $78,409 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 37 and State Senate District 35.
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 45th State Senate District. Akashic. https://akashic.app/sld-upper/17045/. Accessed May 20, 2026. License: CC BY 4.0.