Illinois 21st State Senate District, Illinois: Democratic loyalist district. In 2024, voted D+11%. Democratic peak: D+16 in 2020.
Key facts
- 2024 presidential margin
- D+11MIT Election Lab
- Political archetype
- Democratic loyalistAkashic typology
- Population
- 217,2562024 5-year
- Median household income
- $111,7532024 5-year
- White (non-Hispanic)
- 64.4%2024 5-year
- Black
- 6.1%2024 5-year
- Hispanic / Latino
- 16.7%2024 5-year
- Peak Democratic margin
- D+16 in 2020MIT Election Lab
Constituent county margins for State Senate District 21, ILOne cell per constituent county, colored by 2024 presidential margin from deep red (Republican) through neutral to deep blue (Democratic), ordered bluest first.
R+60D+60
One cell per constituent county. Ordered by 2024 D-vs-R margin (bluest first). Hover for county-level numbers.
5 presidential elections
| Year | Won | Margin | Democratic | Republican | Total |
|---|---|---|---|---|---|
| D | 57,337 | 45,350 | 105,874 | ||
| D | 64,277 | 45,685 | 112,855 | ||
| D | 52,375 | 39,237 | 99,570 | ||
| D | 46,282 | 44,651 | 92,469 | ||
| D | 52,817 | 42,096 | 96,228 |
Demographics
Race, ethnicity, and ancestry
Click any group to see the ancestries typically reported within it.
German
16.2%
Irish
13.0%
Polish
9.8%
Italian
9.7%
English
6.1%
American
2.6%
French
1.5%
Source · American Community Survey 5-year estimates, 2024 release. Hispanic/Latino is an ethnicity that overlaps the race categories, so these shares can total more than 100%. Ancestry is a self-reported, multiple-response item; ancestry percentages do not sum to the parent race percentage.
Age distribution by sex
Median age: 40.0 in this county, 39.1 nationally
Male
Age
Female
85+
75–84
65–74
55–64
45–54
35–44
25–34
18–24
5–17
<5
Source · American Community Survey 5-year estimates, 2024 release.
Median household income
2024 inflation-adjusted dollars
$111,753
State Senate District 21 ranks near the middle of US counties.
State Senate District 21$111,753
Illinois$83,390
United States$80,734
Source · American Community Survey 5-year estimates, 2024 release.
Poverty rate
All persons below federal poverty line
6.7%
Child poverty is below the national average.
Children under 187.5%
Working age (18–64)6.2%
Seniors (65+)9.1%
Source · American Community Survey 5-year estimates, 2024 release.
Language at home
Population aged 5 and older
71.6%
speak English only
Spanish11.8%
Other Indo-European10.5%
Asian & Pacific Islander4.9%
Other languages1.3%
Source · ACS 5-year estimates, 2024.
Religious adherents
Adherents per capita by tradition
Source · 2020 US Religion Census. Remaining 39.7% of residents not counted as adherents by any reporting body.
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.
The Democratic margin in Illinois 21st State Senate District reached its widest at sixteen points in 2020. The margin in 2024 was eleven points — still decisive.
Its loyalty is rooted in its place. Median household income of $111,753, a 64% non-Hispanic-white share, and a population of 217,256 together describe a district whose political habits are deeply settled.
Cite this page
All citations released under CC BY 4.0. Attribution: Akashic Intelligence.
State Senate District 21, Illinois — The Long Memory. Akashic Intelligence — The Long Memory. https://tiers.akashic.app/sld-upper/17021/. Accessed May 20, 2026. License: CC BY 4.0.
License: CC BY 4.0
Frequently asked questions
How did State Senate District 21, Illinois vote in 2024?
In 2024, State Senate District 21, Illinois voted Democratic by 11.3 points (D+11), carried by the Democratic candidate. Out of 105,874 votes cast, 57,337 went Democratic and 45,350 went Republican.
What is State Senate District 21, Illinois's political archetype?
Akashic classifies State Senate District 21, Illinois as a "Democratic loyalist" district based on its long-arc presidential voting pattern. Across 5 elections in the dataset, the district has voted Democratic 5 times, Republican 0 times, and other 0 times.
How many people live in State Senate District 21, Illinois?
State Senate District 21, Illinois 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 State Senate District 21, Illinois?
Median household income in State Senate District 21, Illinois is $111,753 — above the national median of $80,734. The Illinois state median is $83,390.
What is the political history of State Senate District 21, Illinois?
Akashic tracks 5 presidential elections in State Senate District 21, Illinois from 2008 to 2024. Of those, 5 went Democratic and 0 went Republican. The district's archetype — "Democratic loyalist" — captures the overall trajectory of that voting record.