VotePredictor
past elections

Iowa Senate

Theresa Greenfield (D) vs Joni K. Ernst (R)

Actual result
R+6.6
Final polls said
D+1.1
14 late polls · ✗
Model predicted
R+1.8
Winner
Rep

"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
1InsiderAdvantageR+5.61.0
2Selzer & Co.R+4.02.6
3Quinnipiac UniversityR+2.04.6
4VotePredictorR+1.84.8
5The New York Times/Siena CollegeR+1.05.6
6National ResearchR+1.05.6
7Garin-Hart-Yang Research GroupEVEN6.6
8Public Policy PollingD+1.07.6
9Change ResearchD+1.07.6
10CiviqsD+3.09.6
11RMG ResearchD+3.09.6
12Emerson CollegeD+3.19.7
13Data for ProgressD+4.010.6
14YouGovD+4.010.6
15RABA ResearchD+6.012.6
16Monmouth University Polling InstituteD+6.012.6

Forecasters — pre-election win probability, scored by Brier

#ForecasterWin probBrierCalled
1Elections DailyRep 75%0.062
2Sabato's Crystal BallRep 75%0.062
3CNalysisRep 60%0.160
4VotePredictorRep 59%0.169
5FiveThirtyEightRep 58%0.176
6JHK ForecastsRep 52%0.230
7Cook PoliticalDem 50%0.250
8Inside ElectionsDem 50%0.250
9RealClearPoliticsDem 50%0.250
10DDHQ/Decision DeskDem 51%0.260
11The EconomistDem 51%0.260
12Race to the WHDem 52%0.270
13Princeton Election ConsortiumDem 72%0.518

Polls (25)

PollsterDatenPollMiss
Public Policy Polling2020-11-01871D+1.08
Change Research2020-10-311084D+1.08
Civiqs2020-10-31853D+3.010
Emerson College2020-10-30604D+3.110
InsiderAdvantage2020-10-30400R+5.61
Data for Progress2020-10-29951D+4.011
Selzer & Co.2020-10-28814R+4.03
Quinnipiac University2020-10-251225R+2.05
RABA Research2020-10-23693D+6.013
Emerson College2020-10-20435R+4.13
The New York Times/Siena College2020-10-19753R+1.06
InsiderAdvantage2020-10-18400D+4.711
RMG Research2020-10-18800D+3.010
Monmouth University Polling Institute2020-10-17501D+6.013
Data for Progress2020-10-10822D+4.011
YouGov2020-10-081022D+4.011
National Research2020-10-07800R+1.06
Civiqs2020-10-05756D+3.010
Quinnipiac University2020-10-031205D+5.012
Garin-Hart-Yang Research Group2020-09-26400EVEN7
RABA Research2020-09-25780D+12.019
Data for Progress2020-09-25743D+2.09
Monmouth University Polling Institute2020-09-20402D+1.08
The New York Times/Siena College2020-09-19501D+2.09
Selzer & Co.2020-09-16658D+3.010