Pennsylvania House of Representatives seat · lines in effect since 2022
Pennsylvania House District 166
A district of about 60,000 people, 62% of adults with a bachelor's degree. It votes D+24.9 relative to the nation for president.
Where it sits among all 203 seats
Every Pennsylvania House of Representatives seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.
Democratic
Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Every race on these lines
Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.
| 2016 | 2018 | 2022 | 2024 | 2026 | |
|---|---|---|---|---|---|
| U.S. Senate | D+7.2 | D+25.3 | No race | No race | No race |
| Governor | No race | D+26.8 | No race | No race | No race |
| Pennsylvania House of Representatives | No race | No race | D+31.9 | D+20.7 | D+35.1 |
Outlined: the race for this seat itselfBlank: no race that year
Source: 99chambers results archive: precinct results allocated to current lines; 2026: civicAPIUpdated Nov 7, 2026, 3:01 PM ET
Who lives here, compared
Grey bars show the spread of all 203 seats. Small marks are other seats in Pennsylvania. The black marker is District 166.
Higher than 92% of seats.
Lower than 78% of seats.
Lower than 64% of seats.
Lower than 68% of seats.
Higher than 80% of seats.
Denser than 81% of seats.
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET
Seats most like this one
Nearest seats on demographics, density and lean.
District 16557% college gradsD+18.0Held DDistrict 42
62% college gradsD+29.7Held DDistrict 153
56% college gradsD+32.4Held DDistrict 168
67% college gradsD+21.2Held D
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Who has held it
These lines took effect in 2022.
- Judy Trombetta (D)
2027– · Won 2026 by 35.1 - Gregory S. Vitali (D)
2023–2027 · Won 2022 by 31.9, 2024 by 20.7
Source: Past results: 99chambers results archive (MEDSL, Klarner, state election offices)