Who is forecasted today to win the Iowa 3rd District House race?
Updated Monday, October 26, 2026 · 8 days to Election Day · VotePredictor
Zach Nunn is favored. The VotePredictor forecast gives Nunn a 62% chance of beating Sarah Trone Garriott, with a predicted margin of Nunn +1.8. That is still close to a toss-up: Nunn wins about three times in five, and Garriott in the other 38%.
What the forecast is built on
On its 2026 lines the district's 2024 presidential lean is R+2.5 relative to the nation. The House model starts from that lean, adds the national environment as a uniform swing, and weighs incumbency (Zach Nunn holds the seat) and fundraising in the win probability.
- District polls: 1 poll averaging Nunn +6.0, blended with the model by how much each is worth.
- The published forecast: Nunn +1.8, a 62% chance for Nunn.
Misses of a few points are common, so a 1.8-point lead is a 62% chance and not a lock.
How the forecast has moved
Daily tracking of this race began on Oct 26; the trend fills in from here.
The polls
1 poll is in today's forecast. Margins are Democrat minus Republican.
The polls behind it
1 poll · newest firstWhat everyone else says
Rating shops
| Forecaster | Rating | As of |
|---|---|---|
| Cook Political Report | Lean D | Oct 26, 2026 |
| Sabato's Crystal Ball | Lean D | Oct 20, 2026 |
| Inside Elections | Tilt D | Oct 15, 2026 |
0 of 3 rating shops favor Nunn and 3 favor Garriott.
Can you trust this forecast?
Every VotePredictor forecast is scored after the election against the same outcomes as everyone else's. Across 615 past races (Senate, governor, House and president), our final forecasts rank #2 of every forecaster that covered them all (Brier score 0.075, lower is better); FiveThirtyEight is first at 0.074. The full record is on the forecaster rankings and methodology pages.
This article is regenerated every day from the VotePredictor forecast, the poll database, the prediction markets and the rating shops' latest published ratings. Live numbers are on the race page.