Iowa · Governor

How this state voted, 2024 −13.260 points

The state's presidential margin in 2024 as a share of all votes cast, from our own county sums — the same measurement the model's statewide terrain center is built from. Every pull below is measured from here, not from EVEN, which is why a landslide seat's listed pulls are small numbers and still land where the forecast does.

• 2024 presidential result for this state, as a share of all votes cast, from Call the Map's own county sums.
• Same source as Act I's 2024-president reference mark, so the origin lands on it.

Fitted model, above the terrain shown +14.447 points

What the fitted model adds on top of the starting terrain above — incumbency, past results, campaign finance and the other fitted terms — measured from that terrain rather than from EVEN. It is a comparison with the starting point already shown, not a separate input. The source detail lists the variables the fit uses.

• Fitted baseline 1.187 minus starting point -13.260 = 14.447 points.
• Fitted intercept: -6.136 points.
• 2010 White population share used by the frozen historical fit: observed input 91.107. -0.503 × ((91.107 − 77.922) / 12.864) = -0.515 points.
• gov_midterm_wh: observed input -1.000. -0.987 × ((-1.000 − 0.336) / 0.739) = 1.785 points.
• 2024 presidential lean relative to the national result: observed input -11.945. 4.163 × ((-11.945 − -4.415) / 20.258) = -1.548 points.
• Previous governor election margin: observed input -18.520. 1.755 × ((-18.520 − -3.131) / 19.227) = -1.405 points.
• gov_inc_running_signed: observed input 0.000. 2.531 × ((0.000 − -0.120) / 0.708) = 0.428 points.
• gov_inc_tenure_signed: observed input 0.000. 3.340 × ((0.000 − -0.143) / 0.902) = 0.529 points.
• The displayed arithmetic is rounded; the fitted terms use full precision. The intercept plus these five terms gives the non-ratings baseline.
• No source-verified current Gallup reading supports the former 40% / July 2026 claim. The current Gallup series ends in 2025; the Presidency Project identifies its 2026 observations as other pollsters. Use the unchanged fitted missing-value rule, not a replacement polling scale.
• Certified 2024 presidential baseline: state R+13.4, national R+1.5; subtracting the national margin gives relative lean −11.9. Source: FEC compilation of certified state results.

This race’s polls +1.898 points

What this race’s own recent polling adds beyond its prior. The forecast weights each poll for recency and sample size and counts each pollster once; the weights listed here are those of the polls’ own average.

• Echelon Insights (2026-10-23, n=403): D+4.0 · weight 0.52 in the poll average
• co/efficient (2026-10-19, n=863): D+4.0 · weight 0.72 in the poll average
• New River Strategies/GS Strategy Group (2026-10-13, n=602): D+11.0 · weight 0.56 in the poll average
• National Public Affairs (2026-10-12, n=678): D+5.0 · weight 0.59 in the poll average
• YouGov (2026-10-12, n=2,244): D+6.0 · weight 0.83 in the poll average
• Marist University (2026-10-11, n=1,100): D+7.0 · weight 0.74 in the poll average
• … and 16 more below.
• Poll average D+7.2, from 21 polls · 22 recorded polls. This is the polls’ own average, each poll at its published margin, the figure this page’s poll summary shows. In governor races the forecast then counts a poll sponsored by a party or campaign at full weight and moves its margin 2 points against that party, which puts the average it reads at D+7.5. It then applies a fitted correction of 2.5 points toward Republicans for governor races, measured from past polling error, before blending it with its other evidence. The forecast gives the polls 98% of the weight against its structural prior for this race, which moves the margin 1.9 points away from Republicans from where it stood before the polls. Eligible polls: latest poll: 2026-10-23 (5 days old).

National environment +1.838 points

The contribution to this race’s margin, not the national polling margin itself. The race’s loading, reference level and polling blend determine how much of the national climate reaches its final forecast.

• The national environment in this edition is D+8.4. This row is its contribution to the race’s prior, not a claim that the country is D+1.8.
• This step’s recorded contribution to the margin is +1.8.
• The elasticity is fitted on the pooled panel of contested governor races (2010–2024) with cycle-clustered standard errors; it is a measured response to the national environment, not a judgment floor.

Historical error calibration +1.525 points

A prior-election residual correction, when an admitted model publishes one.

• The forecast’s calibration against past governor results. The recorded contribution is +1.5.

Votes for other candidates −0.150 points

Every step above is measured between the two major-party candidates alone, as if nobody else were on the ballot. The forecast sets 2.3% of the vote aside for other candidates and write-ins, so as a share of every vote cast the gap between the two is smaller by that much. This step is exactly that: the two-party margin times the share going to other candidates. It is the same arithmetic that turns the two-party margin into the two shares printed at the top of the page.