VotePredictor
past elections

California House

Jim Costa (D) vs Elizabeth Heng (R)

Actual result
D+15.1
Final polls said
D+11.0
1 late poll · ✓
Model predicted
D+11.0
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
1VotePredictorD+11.04.1
2SurveyUSAD+11.04.1

Forecasters — pre-election win probability, scored by Brier

#ForecasterWin probBrierCalled
1FiveThirtyEightDem 98%0.000
2The EconomistDem 97%0.001
3VotePredictorDem 97%0.001
4DDHQ/Decision DeskDem 95%0.002
5Cook PoliticalDem 90%0.010
6Sabato's Crystal BallDem 90%0.010

Polls (1)

PollsterDatenPollMiss
SurveyUSA2018-09-16515D+11.04