Overview
- District ID
- pa-hd-166
- State
- Pennsylvania
- Chamber
- Lower chamber
- District Code
- 166
- Land Area
- 13.5 sq mi
- Water Area
- 0 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 |
|---|
| Delaware County | 13.47 sq mi | 100.0% | 7.3% |
Showing all 1 county
Places
Showing all 4 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 |
|---|
| PA District 5 | 63,022 | 100.0% | 8.2% | 100.0% |
Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).
Voters
- Registered Voters
- 48,689
- Active Voters
- 46,762 (96.0%)
Party Registration
| Party | Voters | Share |
|---|
| Democratic | 23,427 | 48.1% |
| Republican | 17,881 | 36.7% |
| Unaffiliated | 6,565 | 13.5% |
| Other parties | 763 | 1.6% |
| No party recorded | 53 | 0.1% |
Turnout by Cycle
| Cycle | General | Democratic Primary | Republican Primary |
|---|
| 2025–2026 | 26,915 (55.3%) | 0 (0.0%) | 0 (0.0%) |
| 2023–2024 | 41,717 (85.7%) | 8,453 (17.4%) | 4,910 (10.1%) |
| 2021–2022 | 33,195 (68.2%) | 0 (0.0%) | 0 (0.0%) |
| 2019–2020 | 35,915 (73.8%) | 10,005 (20.5%) | 5,732 (11.8%) |
| 2017–2018 | 27,461 (56.4%) | 0 (0.0%) | 0 (0.0%) |
| 2015–2016 | 27,996 (57.5%) | 7,709 (15.8%) | 8,428 (17.3%) |
| 2013–2014 | 18,031 (37.0%) | 0 (0.0%) | 0 (0.0%) |
| 2011–2012 | 22,949 (47.1%) | 2,011 (4.1%) | 3,334 (6.8%) |
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 01/05/2026. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".
Demographics
- Total Population
- 63,537 (± 779)
- Median Age
- 40.7
- Median Household Income
- $129,586 (± $5,438)
- High School Graduate or Higher (age 25+)
- 96.5%
- Bachelor's Degree or Higher (age 25+)
- 60.9%
Population by Age
| Group | People | Share |
|---|
| Under 18 | 15,432 | 24.3% |
| 18 to 64 | 35,418 | 55.7% |
| 65 and over | 12,687 | 20.0% |
Population by Race and Hispanic Origin
| Group | People | Share |
|---|
| Hispanic or Latino (any race) | 2,305 | 3.6% |
| White, not Hispanic | 52,509 | 82.6% |
| Black, not Hispanic | 1,597 | 2.5% |
| Asian, not Hispanic | 4,336 | 6.8% |
| American Indian / Alaska Native, not Hispanic | 3 | 0.0% |
| Native Hawaiian / Pacific Islander, not Hispanic | 0 | 0.0% |
| Some other race, not Hispanic | 248 | 0.4% |
| Two or more races, not Hispanic | 2,539 | 4.0% |
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
- 62,311
- Citizen Voting Age Population (CVAP)
- 46,901
Citizen Population by Race/Ethnicity
| Group | Citizens | Share |
|---|
| Non-Hispanic | 60,125 | 96.5% |
| Hispanic | 2,187 | 3.5% |
| White | 52,938 | 85.0% |
| Black | 1,582 | 2.5% |
| Asian | 3,856 | 6.2% |
| American Indian / Alaska Native | 2 | 0.0% |
| Native Hawaiian / Pacific Islander | 0 | 0.0% |
| Two or More Races | 276 | 0.4% |
Citizen Voting Age Population by Race/Ethnicity
| Group | CVAP | Share |
|---|
| Non-Hispanic | 45,497 | 97.0% |
| Hispanic | 1,403 | 3.0% |
| White | 40,641 | 86.7% |
| Black | 1,446 | 3.1% |
| Asian | 3,162 | 6.7% |
| American Indian / Alaska Native | 106 | 0.2% |
| Native Hawaiian / Pacific Islander | 0 | 0.0% |
| Two or More Races | 144 | 0.3% |
Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).
