Election Day, Nov 3 6 daysSenate D 85%House D 97%Governors D 86%Forecast updated Oct 28
2026 forecast · South Dakota at-large

Marty Jackley is all but certain to win South Dakota's at-large District.

Nikki Gronli vs Marty Jackley, an open seat. The model has Jackley ahead by 14.9 points, winning 98 percent of 2,000 simulated elections.

Safe RModel R +14.9Polls R +0.0Updated October 28, 2026
Nikki Gronli
Democrat
42.5%
163,931 projected votes
Marty Jackley
Republican
57.5%
221,586 projected votes
98%Jackley
2%Gronli
Jackley all but certainEach square is one simulated election night, Jackley wins about 98 of 100
RatingSafe R98% chance for Jackley
Model marginR +14.9Polls R +0.0
80 percent rangeR +5.9 to R +23.82,000 simulations
Projected votes385,517Jackley 57.5%

The district map

Every district in the state, shaded by its rating

South Dakota districts

1 districts
Safe DLikely DLean DToss upLean RLikely RSafe R

Vote share

Each candidate's projected share and the range of 80 percent of simulations

Nikki GronliDemocrat · 2% to win
42.5%
Marty JackleyRepublican · 98% to win
57.5%

Scale runs from 25 to 75 percent. The dot is the forecast, the band is the 80 percent range and the brighter tick marks 50 percent.

Projected district vote

385,517 votes
CandidateVotesShare
Marty Jackley R221,58657.5%
Nikki Gronli D163,93142.5%
Total385,517100%

Each candidate's expected vote in the On Point simulation, at the forecast's projected turnout.

The trend

Each side's chance of winning over the forecast's recent updates

0%25%50%75%100%2% Gronli98% Jackley18 updates agoToday

Polling

Every poll in the average, and how the model reads it

The South Dakota governor polling average
30%35%40%45%50%55%60%Sep 1Sep 8Sep 15Sep 22Sep 29Oct 6Oct 13Oct 2038.0Ahlers56.0Rhoden
The line is the On Point average: a robust LOWESS fit through the polls, weighted by recency, sample, voter screen and pollster grade, refit three times so outliers count for lessDot size is each poll's weight todayHollow dot: a lean firm's poll as published; the filled dot is where the average counts it, after its measured lean is taken offHover or use the arrow keys to read any day
What moves the average today
Emerson CollegeOct 20 · 803 LV · Gold99%Rhoden +18.0
Concord Public Opinion Partners (D)Oct 8 · 400 LV · NR0.5%Rhoden +10.0
Mason-Dixon for South Dakota News Watch and USD Chiesman CenterOct 14 · 500 LV · D-<1%Rhoden +20.0

This is the same On Point polling average as the full average page. The forecast reads the polls through its own Election Day projection, shown as the On Point average in the table below, and blends it with partisan lean and fundamentals.

Polls of the race

Full average
PollsterSampleAgeMargin
On Point averageWeighted averageR +0.0

Each margin is the poll as the pollster published it. The forecast counts every poll after its house effect and the undecided split, which is what the trail above shows; hover a margin for the counted value. Lean R and Lean D mark partisan leaning firms.

Model margin
Jackley +14.9
Chance of winning
Nikki Gronli2%
Marty Jackley98%
Simulated vote
Nikki Gronli42.5%
Marty Jackley57.5%
How the model gets there
Partisan leanD +29.0
FundamentalsR +13.2
With pollsR +14.9

How we got here

From the state's partisan lean to the forecast, one stage at a time

D +35R +35Partisan leanthe state's baselineD +29.0Fundamentalsapproval, economy, candidatesR +13.2With pollsaverage R +0.0R +14.9
On Point on YouTubeThe South Dakota House race, explained on YouTubeForecast breakdowns, the polls and election night coverage on the On Point channel.Subscribe
Methodology
Every county is rebuilt by simulating voters going to the polls, 2,000 times, from On Point Polling survey data, past results, and the polling average. How the model works.