state senate districtIllinois 21st State Senate District
presidential margin
2004–2024 · Democratic minus Republican
2004R+9.4
2008D+10.7
2012D+0.9
2016D+18.8
2020D+25.2
2024D+22.0
net swing · 2004→2024D+31.4R+9.4 → D+22.0
vs. U.S. · 2024D+23.5D+22.0 vs R+1.5
presidential returns
2024 turnout 74.3% of 152,910 citizens 18+
Year
Democrat
Republican
Others
Total
CVAP
Turnout
2024
67,384
42,359
3,836
113,579
152,910
74.3%
2020
74,484
43,982
2,656
121,122
152,162†
79.6%
2016
59,520
39,241
9,178
107,939
150,142†
71.9%
2012
50,870
49,980
1,706
102,556
145,454†
70.5%
2008
57,932
46,607
1,490
106,029
145,222†
73.0%
2004
45,113
54,547
911
100,571
144,989†
69.4%
† Citizen voting-age population estimated for prior cycles from the constituent-county ACS trend anchored to the current figure. Source: ACS 5-year, table B05003.
——
D+60R+60
20042024
Boundary by 2024 margin · Precinct returns · VEST · MIT Election Lab
People and households
Who lives here
Exact values for this place, its state, and the United States.
Race · ethnicity · ancestry
Communities and origins
GroupIL SD 21IllinoisUnited States
German18.2%16.1%12.5%
Irish14.7%10.6%9.4%
Italian11.1%5.4%4.8%
Polish11.0%6.0%2.2%
English7.0%6.9%9.5%
American2.9%3.3%5.3%
Swedish2.4%1.5%—
French1.6%0.7%1.6%
Asian Indian6.6%2.1%1.4%
Filipino2.1%1.0%0.9%
Chinese1.7%1.0%1.3%
Pakistani1.3%0.3%—
Korean0.6%0.4%0.4%
Vietnamese0.4%0.2%0.6%
Burmese0.2%——
Taiwanese0.2%——
Mexican6.7%14.4%11.3%
Puerto Rican0.7%1.7%1.8%
Guatemalan0.3%0.3%0.5%
Cuban0.2%0.2%0.7%
Colombian0.2%0.3%0.4%
Venezuelan0.2%——
African American†4.1%12.1%9.9%
African0.3%0.5%0.5%
Jamaican0.2%—0.4%
Hispanic or Latino counts residents of any race; the race groups count only their non-Hispanic residents, so the groups are mutually exclusive and sum to 100%. Expand a row to see ancestries reported within that group.
Age and life stage
Measure
IL SD 21
Illinois
United States
Median age
39.2
39.1
39.1
Age 18–24
8.3%
9.1%
9.2%
Age 65 and older
17.3%
16.9%
17.2%
Household economy
Measure
IL SD 21
Illinois
United States
Median household income
$125,645
$83,390
$84,427
Poverty rate
6.0%
11.8%
12.5%
Bachelor's degree or higher (25+)
51.0%
37.9%
35.6%
Languages at home
Measure
IL SD 21
Illinois
United States
Speaks a non-English language at home
29.2%
24.1%
22.3%
Spanish
11.6%
14.0%
13.6%
Russian, Polish, or other Slavic
3.8%
2.5%
0.7%
Other Indo-European
6.9%
2.6%
2.0%
Other Asian & Pacific Island
2.1%
1.0%
1.1%
Religious landscape
Measure
IL SD 21
Illinois
United States
Catholic
—
24.2%
18.6%
Evangelical Protestant
—
11.7%
16.5%
Unclaimed / not counted
—
49.2%
51.5%
American Community Survey 2024 5-year (CVAP, income, age, poverty, education, language, race, ancestry) · presidential returns from MIT Election Lab through 2024 · 2020 U.S. Religion Census (ASARB) — congregational adherents; unclaimed is the residual not counted by congregations.
Illinois 21st State Senate District
presidential history
Presidential margin, 2004–2024
Democratic minus Republican, by election
Presidential margin over time
Year
Margin (D minus R)
2004
−9.4%
2008
+10.7%
2012
+0.9%
2016
+18.8%
2020
+25.2%
2024
+22.0%
DemocraticRepublican
6 presidential elections
Third column names the leading third-party or independent finisher. Source · MIT Election Lab · ICPSR · VEST (precinct-level 2024). Swing · margin change from the prior cycle. vs U.S. · margin relative to the national result that year. Third-party votes in 2012 are allocated from certified county totals by this place's share of each county's two-party vote — that cycle's precinct source records two-party splits. † 2004 sub-county results are estimated: the source's block-level detail for this cycle was unreliable — either county/municipality-level consolidated reporting (COVID-era) or a precinct-to-block allocation that misplaced votes — so the figures are allocated from the constituent county totals in proportion to the place and scaled to certified totals.
Year
Won
Democratic
Republican
Other
Margin
Swing
vs U.S.
Total
D
59.3%Harris67,384
37.3%Trump42,359
3.4%
D+22.0
R+3.1
D+23.5
113,579
D
61.5%Biden74,484
36.3%Trump43,982
2.2%
D+25.2
D+6.4
D+20.7
121,122
D
55.1%Clinton59,520
36.4%Trump39,241
8.5%
D+18.8
D+17.9
D+16.7
107,939
D
49.6%Obama50,870
48.7%Romney49,980
1.7%
D+0.9
R+9.8
R+3.0
102,556
D
54.6%Obama57,932
44.0%McCain46,607
1.4%
D+10.7
D+20.1
D+3.4
106,029
R
44.9%Kerry45,113
54.2%Bush54,547
0.9%
R+9.4
—
R+6.9
100,571
current representation
Current officeholders
DLaura EllmanState Senate · 21
State legislative officeholder from OpenStates nightly current-legislator data.
With a 2024 presidential margin of R+46.6, this downstate district ranks among the most reliably conservative constituencies in Illinois, reflecting the sharp rural-urban divide that defines the state's political geography.
Across the recorded series it reached a Democratic high of 25.2 points in 2020 and a Republican high of 9.4 points in 2004. Between 2020 and 2024 the district moved 3.1 points toward the Republican candidate; the 2024 margin was 22.0 points.
A population of 217,256, a 68% non-Hispanic-white share, and a median household income of $125,645 describe the district. The district's voting pattern over the last decade is most similar to that of State Senate District 41 and State Senate District 27.
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 →
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
Illinois 21st State Senate District. Akashic. https://akashic.app/sld-upper/17021/. Accessed May 20, 2026. License: CC BY 4.0.
How did Illinois 21st State Senate District vote in 2024?
In 2024, Illinois 21st State Senate District voted Democratic by 22.0 points (D+22.0), carried by the Democratic candidate. Out of 113,579 votes cast, 67,384 went Democratic and 42,359 went Republican.
When did Illinois 21st State Senate District last vote Republican?
The most recent presidential election in which Illinois 21st State Senate District voted Republican was 2004.
How many people live in Illinois 21st State Senate District?
Illinois 21st State Senate District has a population of 217,256 according to the 2024 American Community Survey 5-year estimates from the US Census Bureau.
What is the median household income in Illinois 21st State Senate District?
Median household income in Illinois 21st State Senate District is $125,645 — above the national median of $80,734. The Illinois state median is $83,390.
What is the political history of Illinois 21st State Senate District?
Akashic tracks 6 presidential elections in Illinois 21st State Senate District from 2004 to 2024. Of those, 5 went Democratic and 1 went Republican.
