VotePredictor
past elections

California House

Katie Porter (D) vs Mimi Walters (R)

Actual result
D+4.1
Final polls said
R+3.6
3 late polls · ✗
Model predicted
R+3.6
Winner
Dem

"Final polls said" averages polls from the last ~3 weeks — the call right before the vote, and how pollsters are rated. The model's prediction is walk-forward (trained only on earlier races).

Final rankings

How everyone who called this race did, ranked — VotePredictor shown inline (★).

Pollsters — each pollster's final poll vs the result

#PollsterFinal callMissCalled
1Global Strategy GroupD+3.01.1
2The New York Times/Siena CollegeD+1.32.8
3University of California Berkeley Institute of Governmental StudiesD+7.02.9
4GBAOD+1.03.1
5VotePredictorR+3.67.7
6Public Opinion StrategiesR+4.08.1
7TargetPointR+8.012.1

Forecasters — pre-election win probability, scored by Brier

#ForecasterWin probBrierCalled
1Sabato's Crystal BallDem 75%0.062
2FiveThirtyEightDem 65%0.122
3The EconomistDem 59%0.171
4DDHQ/Decision DeskDem 53%0.226
5Cook PoliticalDem 50%0.250
6VotePredictorRep 53%0.279

Polls (7)

PollsterDatenPollMiss
The New York Times/Siena College2018-10-29499D+1.33
Public Opinion Strategies2018-10-16400R+4.08
TargetPoint2018-10-15365R+8.012
The New York Times/Siena College2018-09-23518D+4.91
GBAO2018-09-22400D+1.03
University of California Berkeley Institute of Governmental Studies2018-09-20519D+7.03
Global Strategy Group2018-09-16500D+3.01