House District 166
Collar counties · currently held by D (Greg Vitali, not running) · open seat
Forecast
100%
chance Judith Trombetta (D) wins
- Democrat
- Judith Trombetta
- Republican
- Joseph William Walker
- Rating
- Safe D
- Expected margin
- D+30.2 (90% range D+17.5 to D+43.0)
- Chance of flipping
- 0.0%
- Tipping-point chance
- 0.1% (chance this seat decides control)
How the forecast was built
| Statewide generic legislative margin (environment) | D+6.6 |
| + District partisan lean | +25.7 |
| = Fundamentals before candidates | D+32.3 |
| = Fundamentals margin | D+32.3 |
| No public district polls | |
| External ratings prior (weight 25%) | -2.1 |
| Final expected margin | D+30.2 |
District-level error SD 6.7 pts; total with statewide and regional error ≈ 7.8 pts.
Inputs
Partisan lean (current lines)
| Race | District | Statewide | Lean | Weight |
|---|---|---|---|---|
| 2024 President | D+24.2 | R+1.8 | +25.9 | 0.45 |
| 2022 Governor | D+40.5 | D+15.0 | +25.5 | 0.2 |
| 2022 U.S. Senate | D+29.2 | D+5.0 | +24.2 | 0.2 |
| 2020 President | D+27.2 | D+1.1 | +26.1 | 0.15 |
Last legislative result (2024): D+20.7 vs a statewide legislative environment of R+8.2 → lean +26.1, blended at 30%.
Candidates & money
- Incumbent
- Greg Vitali (D)
- Receipts
- no matched PA DoS filings for both sides
Past results in this district
| Year | Democrat | Republican | Margin |
|---|---|---|---|
| 2024 | Gregory Vitali | Kimberly C Dugery | D+20.7 |
| 2022 | Gregory S. Vitali | Kimberly J Razzano | D+32.2 |
| 2020 | Greg Vitali | Christine E Boyle | D+41.8 |
External ratings
| Source | Rating | Implied P(Dem) | Weight | As of |
|---|---|---|---|---|
| state_navigate | Safe D (solid d) | 100% | 0.25 | 2026-10-15 |
Ratings are blended as a prior, not copied: they moved this seat's expected margin by -2.1 points.