Overview
- District ID
- il-sd-042
- State
- Illinois
- Chamber
- Upper chamber (state senate)
- District Code
- 042
- Land Area
- 87.8 sq mi
- Water Area
- 1.44 sq mi
Boundary
Boundary as GeoJSON
Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.
Counties
Showing all 4 counties
Places
Showing all 11 places
Overlapping Congressional Districts
| Congressional district | Population in both | Share of this district's population | Share of the congressional district's population | Share of this district's land |
|---|
| IL District 14 | 114,942 | 52.9% | 15.3% | 59.8% |
| IL District 11 | 99,187 | 45.7% | 13.2% | 39.1% |
| IL District 8 | 3,029 | 1.4% | 0.4% | 1.1% |
Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).
Voters
- Registered Voters
- 150,039
- Active Voters
- 135,263 (90.2%)
Party Registration
This state's voter file does not record party registration.
Turnout by Cycle
| Cycle | General | Democratic Primary | Republican Primary |
|---|
| 2025–2026 | 28,973 (19.3%) | 1,651 (1.1%) | 382 (0.3%) |
| 2023–2024 | 97,985 (65.3%) | 11,428 (7.6%) | 8,007 (5.3%) |
| 2021–2022 | 68,274 (45.5%) | 12,800 (8.5%) | 11,535 (7.7%) |
| 2019–2020 | 90,357 (60.2%) | 25,359 (16.9%) | 9,061 (6.0%) |
| 2017–2018 | 66,033 (44.0%) | 14,981 (10.0%) | 9,265 (6.2%) |
| 2015–2016 | 68,396 (45.6%) | 20,528 (13.7%) | 17,470 (11.6%) |
| 2013–2014 | 38,840 (25.9%) | 2,417 (1.6%) | 9,925 (6.6%) |
| 2011–2012 | 50,042 (33.4%) | 3,993 (2.7%) | 10,073 (6.7%) |
Turnout counts today's registered voters with a counted ballot in the cycle's elections (the odd and even year), as a share of today's registered voters. Voters who have since left the rolls are not counted.
Browse the voter list for this district (premium access; sign-in required)
Source: Civitech voter file snapshot as of 12/15/2025. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".
Demographics
- Total Population
- 219,172 (± 3,360)
- Median Age
- 37.5
- Median Household Income
- $109,846 (± $4,611)
- High School Graduate or Higher (age 25+)
- 92.6%
- Bachelor's Degree or Higher (age 25+)
- 47.0%
Population by Age
| Group | People | Share |
|---|
| Under 18 | 54,410 | 24.8% |
| 18 to 64 | 136,722 | 62.4% |
| 65 and over | 28,040 | 12.8% |
Population by Race and Hispanic Origin
| Group | People | Share |
|---|
| Hispanic or Latino (any race) | 47,334 | 21.6% |
| White, not Hispanic | 118,089 | 53.9% |
| Black, not Hispanic | 20,834 | 9.5% |
| Asian, not Hispanic | 23,821 | 10.9% |
| American Indian / Alaska Native, not Hispanic | 90 | 0.0% |
| Native Hawaiian / Pacific Islander, not Hispanic | 6 | 0.0% |
| Some other race, not Hispanic | 1,014 | 0.5% |
| Two or more races, not Hispanic | 7,984 | 3.6% |
Source: U.S. Census Bureau, American Community Survey 2020-2024 ACS 5-year estimates (tables B01001, B01002, B01003, B03002, B15003, B19013) for this state legislative district. Estimates are survey-based; ± figures are 90% margins of error.
Citizen Voting Age Population
- Total Citizen Population
- 197,721
- Citizen Voting Age Population (CVAP)
- 145,569
Citizen Population by Race/Ethnicity
| Group | Citizens | Share |
|---|
| Non-Hispanic | 158,862 | 80.3% |
| Hispanic | 38,858 | 19.7% |
| White | 117,503 | 59.4% |
| Black | 20,225 | 10.2% |
| Asian | 15,686 | 7.9% |
| American Indian / Alaska Native | 89 | 0.0% |
| Native Hawaiian / Pacific Islander | 5 | 0.0% |
| Two or More Races | 369 | 0.2% |
Citizen Voting Age Population by Race/Ethnicity
| Group | CVAP | Share |
|---|
| Non-Hispanic | 120,273 | 82.6% |
| Hispanic | 25,294 | 17.4% |
| White | 92,708 | 63.7% |
| Black | 15,466 | 10.6% |
| Asian | 11,300 | 7.8% |
| American Indian / Alaska Native | 685 | 0.5% |
| Native Hawaiian / Pacific Islander | 9 | 0.0% |
| Two or More Races | 236 | 0.2% |
Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).
