Illinois 31st 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
59.9%
60,637 votes · D+22.6 · modeled estimate
Runner-up · Kamala Harris, 2024 · 58.0%
Republican
Warren G. Harding1920
82.9%
4,957 votes · R+72.3 · modeled estimate
Runner-up · Theodore Roosevelt, 1904 · 79.9%
Most votes
Largest number of votes cast for the party’s presidential nominee here.
Democratic
Joe Biden2020
60,637votes
59.9% of the vote · D+22.6 · modeled estimate
Runner-up · Kamala Harris, 2024 · 53,437 votes
Republican
George W. Bush2004
43,629votes
52.4% of the vote · R+5.5 · modeled estimate
Runner-up · Mitt Romney, 2012 · 40,702 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
+19.7pts D vs U.S.
Place D+18.2 · U.S. R+1.5 · modeled estimate
Runner-up · Joe Biden, 2020 · +18.1 pts
Republican
William McKinley1896
+47.6pts R vs U.S.
Place R+53.7 · U.S. R+6.1 · modeled estimate
Runner-up · Warren G. Harding, 1920 · +46.1 pts
current representation
Current officeholders
DMary Edly-AllenState Senate · 31
State legislative officeholder from OpenStates nightly current-legislator data.
U.S. House elections · 2 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
59.2%55,347
40.8%38,191
93,538
2020
D
60.1%60,282
39.9%39,985
100,267
Illinois 31st State Senate District sits in the Upper Midwest. In 2024 it voted Democratic.
Across the recorded series it reached a Democratic high of 22.6 points in 2020 and a Republican high of 72.3 points in 1920. Between 2020 and 2024 the district moved 4.4 points toward the Republican candidate; the 2024 margin was 18.2 points.
A population of 217,217, a 52% non-Hispanic-white share, and a median household income of $102,203 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 42 and State Senate District 25.
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.
How did Illinois 31st State Senate District vote in 2024?
In 2024, Illinois 31st State Senate District voted Democratic by 18.2 points (D+18.2), carried by the Democratic candidate. Out of 92,110 votes cast, 53,437 went Democratic and 36,677 went Republican.
When did Illinois 31st State Senate District last vote Republican?
The most recent presidential election in which Illinois 31st State Senate District voted Republican was 2004.
How many people live in Illinois 31st State Senate District?
Illinois 31st State Senate District has a population of 217,217 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Illinois 31st State Senate District?
Median household income in Illinois 31st State Senate District is $102,203 — above the national median of $80,734. The Illinois state median is $83,390.
What is the political history of Illinois 31st State Senate District?
Akashic tracks 38 presidential elections in Illinois 31st State Senate District from 1876 to 2024. Of those, 5 went Democratic and 32 went Republican.