VotePredictor
past elections

California House

Jim Costa (D) vs Andy Vidak (R)

Actual result
D+3.4
Final polls said
R+2.0
2 late polls · ✗
Model predicted
R+5.6
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
1Normington, Petts & AssociatesD+6.02.6
2VotePredictorR+5.69.0
3SurveyUSAR+10.013.4
4ccAdvertisingR+23.326.7

Polls (4)

PollsterDatenPollMiss
SurveyUSA2010-10-23601R+10.013
Normington, Petts & Associates2010-10-23400D+6.03
ccAdvertising2010-09-29442R+23.327
SurveyUSA2010-09-11561D+2.01