Illinois State Senate District 35

State Legislative District Profile (Upper Chamber)

Overview

District ID
il-sd-035
State
Illinois
Chamber
Upper chamber (state senate)
District Code
035
Land Area
944 sq mi
Water Area
2.96 sq mi

Boundary

Boundary of Illinois State Senate District 35

Boundary as GeoJSON

Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.

Counties

CountyOverlapShare of district landShare of county land
McHenry County378.85 sq mi40.1%62.8%
Kane County258.65 sq mi27.4%49.8%
DeKalb County157.47 sq mi16.7%24.9%
Boone County141.54 sq mi15.0%50.4%
Winnebago County7.59 sq mi0.8%1.5%

Showing all 5 counties

Places

PlaceOverlapShare of district landShare of place land
Huntley village14.29 sq mi1.5%97.5%
Sugar Grove village10.20 sq mi1.1%97.2%
Hampshire village9.51 sq mi1.0%95.0%
Sycamore city9.50 sq mi1.0%93.9%
Marengo city8.54 sq mi0.9%95.9%
Harvard city8.36 sq mi0.9%99.7%
Poplar Grove village6.86 sq mi0.7%87.1%
Burlington village6.86 sq mi0.7%100.0%
Gilberts village5.21 sq mi0.6%94.9%
Lake in the Hills village4.41 sq mi0.5%43.2%
Big Rock village4.32 sq mi0.5%100.0%
Rockford city4.11 sq mi0.4%6.3%
Cortland town3.65 sq mi0.4%100.0%
Pingree Grove village3.54 sq mi0.4%87.7%
Lakewood village3.36 sq mi0.4%73.3%
Richmond village2.84 sq mi0.3%66.3%
Greenwood village2.63 sq mi0.3%99.1%
Virgil village2.18 sq mi0.2%100.0%
Maple Park village2.15 sq mi0.2%94.1%
Elgin city2.01 sq mi0.2%5.3%
Woodstock city2.00 sq mi0.2%15.2%
Hebron village1.93 sq mi0.2%98.7%
Candlewick Lake CDP1.85 sq mi0.2%100.0%
Algonquin village1.79 sq mi0.2%14.3%
Wonder Lake village1.77 sq mi0.2%35.6%

Showing top 25 of 54 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
IL District 1199,17745.7%13.2%42.5%
IL District 1644,65020.6%5.9%25.8%
IL District 1441,95119.3%5.6%21.3%
IL District 822,26610.3%3.0%3.4%
IL District 109,0024.1%1.2%6.9%
IL District 1781<0.1%<0.1%<0.1%

Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).

Voters

Registered Voters
162,058
Active Voters
154,014 (95.0%)

Party Registration

This state's voter file does not record party registration.

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2025–202628,958 (17.9%)223 (0.1%)419 (0.3%)
2023–2024119,084 (73.5%)9,524 (5.9%)14,905 (9.2%)
2021–202285,904 (53.0%)9,924 (6.1%)22,379 (13.8%)
2019–2020106,821 (65.9%)19,829 (12.2%)13,985 (8.6%)
2017–201877,857 (48.0%)13,185 (8.1%)16,626 (10.3%)
2015–201683,046 (51.2%)17,627 (10.9%)29,553 (18.2%)
2013–201451,832 (32.0%)1,868 (1.2%)16,289 (10.1%)
2011–201263,108 (38.9%)2,639 (1.6%)16,279 (10.0%)

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
217,029 (± 1,544)
Median Age
40.5
Median Household Income
$109,729 (± $3,291)
High School Graduate or Higher (age 25+)
95.1%
Bachelor's Degree or Higher (age 25+)
39.9%

Population by Age

GroupPeopleShare
Under 1853,50424.7%
18 to 64124,72857.5%
65 and over38,79717.9%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)31,98514.7%
White, not Hispanic165,19376.1%
Black, not Hispanic4,5082.1%
Asian, not Hispanic7,4843.4%
American Indian / Alaska Native, not Hispanic450.0%
Native Hawaiian / Pacific Islander, not Hispanic00.0%
Some other race, not Hispanic6840.3%
Two or more races, not Hispanic7,1303.3%

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
210,195
Citizen Voting Age Population (CVAP)
157,126

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic182,72086.9%
Hispanic27,46813.1%
White166,94879.4%
Black4,2702.0%
Asian6,5433.1%
American Indian / Alaska Native450.0%
Native Hawaiian / Pacific Islander00.0%
Two or More Races6030.3%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic141,39490.0%
Hispanic15,73210.0%
White130,63983.1%
Black3,2662.1%
Asian6,1023.9%
American Indian / Alaska Native9570.6%
Native Hawaiian / Pacific Islander20.0%
Two or More Races4270.3%

Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).