VotePredictor
past elections

Iowa Senate

Art Small (D) vs Chuck Grassley (R)

Actual result
R+42.3
Final polls said
R+44.7
3 late polls · ✓
Model predicted
R+41.1
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
1VotePredictorR+41.11.2
2Zogby AnalyticsR+46.03.7
3Opinion DynamicsR+47.04.7

Polls (4)

PollsterDatenPollMiss
Zogby Analytics2004-10-30602R+46.04
Opinion Dynamics2004-10-30700R+47.05
Zogby Analytics2004-10-26600R+41.01
Opinion Dynamics2004-09-21700R+40.02