Overview
- District ID
- il-hd-042
- State
- Illinois
- Chamber
- Lower chamber
- District Code
- 042
- Land Area
- 30.4 sq mi
- Water Area
- 0.6 sq mi
Boundary
Boundary as GeoJSON
Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.
Counties
| County | Overlap | Share of district land | Share of county land |
|---|
| DuPage County | 30.37 sq mi | 100.0% | 9.3% |
Showing all 1 county
Places
Showing all 8 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 6 | 98,488 | 90.6% | 13.1% | 91.9% |
| IL District 3 | 6,686 | 6.2% | 0.9% | 5.2% |
| IL District 11 | 3,503 | 3.2% | 0.5% | 2.9% |
Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).
Voters
- Registered Voters
- 85,207
- Active Voters
- 77,326 (90.8%)
Party Registration
This state's voter file does not record party registration.
Turnout by Cycle
| Cycle | General | Democratic Primary | Republican Primary |
|---|
| 2025–2026 | 19,759 (23.2%) | 532 (0.6%) | 0 (0.0%) |
| 2023–2024 | 58,621 (68.8%) | 11,685 (13.7%) | 7,243 (8.5%) |
| 2021–2022 | 44,603 (52.3%) | 11,366 (13.3%) | 8,460 (9.9%) |
| 2019–2020 | 56,457 (66.3%) | 15,650 (18.4%) | 4,951 (5.8%) |
| 2017–2018 | 43,944 (51.6%) | 11,114 (13.0%) | 7,652 (9.0%) |
| 2015–2016 | 45,193 (53.0%) | 13,595 (16.0%) | 14,210 (16.7%) |
| 2013–2014 | 29,074 (34.1%) | 1,950 (2.3%) | 9,994 (11.7%) |
| 2011–2012 | 35,679 (41.9%) | 2,807 (3.3%) | 9,073 (10.6%) |
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
- 106,038 (± 2,004)
- Median Age
- 39.5
- Median Household Income
- $109,443 (± $4,939)
- High School Graduate or Higher (age 25+)
- 96.2%
- Bachelor's Degree or Higher (age 25+)
- 57.2%
Population by Age
| Group | People | Share |
|---|
| Under 18 | 23,209 | 21.9% |
| 18 to 64 | 63,219 | 59.6% |
| 65 and over | 19,610 | 18.5% |
Population by Race and Hispanic Origin
| Group | People | Share |
|---|
| Hispanic or Latino (any race) | 11,562 | 10.9% |
| White, not Hispanic | 74,510 | 70.3% |
| Black, not Hispanic | 4,541 | 4.3% |
| Asian, not Hispanic | 10,902 | 10.3% |
| American Indian / Alaska Native, not Hispanic | 35 | 0.0% |
| Native Hawaiian / Pacific Islander, not Hispanic | 84 | 0.1% |
| Some other race, not Hispanic | 311 | 0.3% |
| Two or more races, not Hispanic | 4,093 | 3.9% |
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
- 99,891
- Citizen Voting Age Population (CVAP)
- 77,306
Citizen Population by Race/Ethnicity
| Group | Citizens | Share |
|---|
| Non-Hispanic | 90,537 | 90.6% |
| Hispanic | 9,357 | 9.4% |
| White | 74,535 | 74.6% |
| Black | 4,396 | 4.4% |
| Asian | 8,612 | 8.6% |
| American Indian / Alaska Native | 34 | 0.0% |
| Native Hawaiian / Pacific Islander | 83 | 0.1% |
| Two or More Races | 214 | 0.2% |
Citizen Voting Age Population by Race/Ethnicity
| Group | CVAP | Share |
|---|
| Non-Hispanic | 71,306 | 92.2% |
| Hispanic | 5,998 | 7.8% |
| White | 59,507 | 77.0% |
| Black | 4,104 | 5.3% |
| Asian | 7,186 | 9.3% |
| American Indian / Alaska Native | 331 | 0.4% |
| Native Hawaiian / Pacific Islander | 28 | 0.0% |
| Two or More Races | 150 | 0.2% |
Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).
