House · 2026

Pennsylvania’s 7th District

Bob Brooks (D)v.Ryan Mackenzie (R)TOSS-UP

Incumbent: Ryan Mackenzie, currently Republican.

Projected margin

D+0.3

Nine in ten outcomes: D+10 to R+10

Chance of winning

52%

Bob Brooks

Polls alone

D+0.7

1 poll from 1 pollster; latest Jul 2. Weight in projection: 57%.

Fundamentals alone

R+0.2

Weight in projection: 43%.

Polls

The average over time

Each poll is first shifted by its sponsor's and its pollster's measured lean, then weighted by recency and track record. Sample size gets no weight: in 2,000-plus past races it predicted nothing about accuracy. Why.

adjusted weighted average shading: which side the average favors each poll, as published party-aligned pollster or sponsor

Before any poll

What the fundamentals say

A regression on past House races, fit without looking at this year. The national environment term uses the generic ballot after its historical correction (D+5.3).

What each term adds to the estimate

BaselineD+0.8

Partisan leanR+1.5

National environmentD+3.6

IncumbencyR+3.6

Incumbent's last over/under-performanceD+0.7

Fundraising gapR+0.3

Fundamentals estimateR+0.2

Input: partisan lean

R+1.7

Presidential vote relative to the nation, 2024 on this year's lines.

Input: raised from itemized individual donors, through June 30

$664K D · $852K R

FEC filings; the model uses the log of the ratio.

Handicappers, for comparison

Cook: Tossup · Sabato: Tossup · Inside Elections: Tossup

Not an input to the projection.

Table view

The one poll in the average

“Share” is how much of today’s average each poll supplies. It depends on recency, the pollster’s record, whether the poll screens for likely voters, and how many other polls the same firm has in the race. It does not depend on sample size.

Dates	Pollster	Sample	Brooks	Mackenzie	As published	Adjusted	Share of average
Jun 29 – Jul 2	GBAODEM.-ALIGNED for House Majority PAC	550 LV	47	43	D+4	D+0.7 moved 3.3 toward R	100%	source

LV: likely voters. RV: registered voters. A: all adults. “Adjusted” is the published margin after removing the sponsor shift and the pollster’s measured house effect; the small print says how far that moved the poll. Dem.-aligned and Rep.-aligned mark polls paid for by a party, a campaign, or an allied group, or taken by a firm whose published work is mostly for one side. They are shifted by the average lean of such polls, then counted at full weight.