VotePredictor
past elections

Massachusetts Senate

Elizabeth Warren (D) vs Geoff Diehl (R)

Actual result
D+24.2
Final polls said
D+24.4
3 late polls · ✓
Model predicted
D+24.4
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+24.40.3
2University of Massachusetts Lowell Center for Public OpinionD+25.00.8
3MassINC Polling GroupD+22.02.2
4Suffolk UniversityD+21.23.0
5Western New England University Polling InstituteD+30.05.8

Forecasters — pre-election win probability, scored by Brier

#ForecasterWin probBrierCalled
1Cook PoliticalDem 99%0.000
2DDHQ/Decision DeskDem 100%0.000
3FiveThirtyEightDem 100%0.000
4JHK ForecastsDem 100%0.000
5Sabato's Crystal BallDem 99%0.000
6Inside ElectionsDem 99%0.000
7VotePredictorDem 100%0.000

Polls (6)

PollsterDatenPollMiss
MassINC Polling Group2018-10-27502D+22.02
Suffolk University2018-10-26500D+21.23
Western New England University Polling Institute2018-10-18402D+30.06
University of Massachusetts Lowell Center for Public Opinion2018-10-04485D+25.01
MassINC Polling Group2018-09-19506D+26.02
Suffolk University2018-09-15500D+29.45