South Dakota · Governor
Open this race on The Map ↗Larry Rhoden is heavily favored to hold the South Dakota governorship. Predicted margin: R+20.4.
high / low: vote share (%) in the middle 80 in 100 simulations
About this field
Not competitive.
Forecast share averages the simulated vote. Win chance counts how often a candidate wins. A wider range of outcomes can give a candidate a higher win chance despite a lower average share.
Forecast history
Latest reading · Sep 13 · first published Sep 9 · 80% range · margin points R+29.5 to R+11.4. Methodology
Hover the line, tap it, or use the arrow keys to inspect its history.
About this series
This comparable series begins on September 9, 2026, when the model version changed to CTMM 2.2. Earlier readings remain in the archive and are not joined as voter movement; faded points before September 9, 2026 are reconstructions, not forecasts issued on those days.
Faded: CTMM 2.2 reconstructed history: computed after the fact with each date's available polls and environment, without expert ratings; not an issued forecast. Issued forecasts begin at the launch marker.
How the margin was built
Follow each contribution to the margin. Wider ribbons mean more percentage points. Tap an input for its calculation and source.
The signed totals combine at the forecast. Displayed values are rounded.
All calculations & sources
How this state voted, 2024 −29.190 points
The state's two-party presidential margin in 2024, 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, two-party, 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 +10.676 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 -18.514 minus starting point -29.190 = 10.676 points.
- Fitted intercept: -6.136 points.
- 2010 White population share used by the frozen historical fit: observed input 85.974. -0.503 × ((85.974 − 77.922) / 12.864) = -0.315 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 -28.390. 4.163 × ((-28.390 − -4.415) / 20.258) = -4.927 points.
- Previous governor election margin: observed input -26.810. 1.755 × ((-26.810 − -3.131) / 19.227) = -2.162 points.
- gov_inc_running_signed: observed input -1.000. 2.531 × ((-1.000 − -0.120) / 0.708) = -3.145 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+29.9, national R+1.5; subtracting the national margin gives relative lean −28.4. Source: FEC compilation of certified state results.
National environment +1.143 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+7.6. This row is its contribution to the race’s prior, not a claim that the country is D+1.1.
- The environment enters once, through the fitted governor elasticity: 0.4216 × (7.600 − 1.882, the environment the governor priors themselves imply) = +2.4; the producer rounds the contribution to +2.4.
- No admitted polling attenuates this contribution here; it reaches the final center in full.
- 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 −2.066 points
A prior-election residual correction, when an admitted model publishes one.
- No separate historical residual correction is published in this governor edition.
Structural safeguards −0.972 points
Bounded corrections that keep the model consistent with structural facts.
- No Senate-style structural calibration is used in the governor model.
The components this edition publishes for this race, in points. “Other factors” closes the sum to the two-party structural lean exactly. Here the structural lean IS the published margin, so the walk sums to the projection exactly; nothing is left over.
| Named factor | Contribution |
|---|---|
| FundamentalsThe admitted fitted baseline. Its surviving variables differ by office; the source detail above identifies those used for this race. | −18.51 |
| Historical calibrationThe House lane's calibration against certified past cycles. | −2.07 |
| National environmentThe national environment’s contribution to the prior. Polling can attenuate its influence; this value is not the national polling margin. | +1.14 |
| Structural terrain safeguardA bounded pull toward presidential terrain in heavily partisan states. | −0.97 |
| Other factors | 0.00 |
Race context
- Forecast votes cast
- 340,397
- Forecast turnout
- 49.6% of the voting-eligible population
- 2024 presidential margin
- R+29.9
Statewide, 50.4% of the voting-eligible population is projected to cast a ballot; the lower figure above is the share projected to vote in this race.
Population profile Select a measure for its source and denominator
U.S. Census Bureau, 2022 American Community Survey 5-year estimates ↗
Coverage
1 quote
- "In politics, as in comedy, timing is everything. That brings us to the curious timing of President Donald Trump’s endorsement of Gov. Larry Rhoden."
COMMENTARY: buff.ly/f5zfRac ↗
South Dakota Searchlight · Official · 23h ago
curated state newsroom · recent Bluesky post · named-race match