South Dakota

U.S. Senate · South Dakota

Election day November 3, 2026 · forecast of November 2, 2026

Our forecast gives the Republicans a 84% chance of winning, with an average lead of 9.6 points.

Competitive. Chance of a final gap under 5 points: 29%.

Projected vote share

Projection by party

Republican 53.9%

Mike Rounds, incumbent
Other 45.7%

What Orbit says

Orbit, our experimental model, picks the same favourite as our main forecast: the Republican, with a 79% chance (84% according to Harfang des neiges).

Model	Favourite	Chance
Harfang des neiges	Republican	84%
Orbit	Republican	79%
50/50 blend	Republican	82%

Figures as of November 2, 2026. The blend averages the two chances; in replays of the 2018 and 2022 Quebec elections, it beat our main forecast on its own.

Every race according to Orbit

Compared with the average

	Republican	Other	Democrat
South Dakota	53.9%	45.7%	0.4%
National averageUnited States	48.3%+5.6	5.7%+40.0	46.0%−45.6

Simple average of the 100 districts, not weighted by population.

Projection track

How the projection has moved

Polls in this district

15 polls

Pollster	Field dates	Sample	Population	Topline	Source
Concord Public Opinion Partners Education Reform Now Advocacy	22–Oct 26, 2026	448	likely voters	Independent and others 43 Republican 41	See the poll
Emerson College KELO-TV	19–Oct 21, 2026	803	likely voters	Republican 54 Independent and others 46	See the poll
Quantus Insights	17–Oct 19, 2026	657	likely voters	Republican 59 Independent and others 37	See the poll
Public Opinion Strategies	12–Oct 16, 2026	500	likely voters	Republican 54 Independent and others 37	See the poll
Mason-Dixon Polling & Research, Inc. Chiesman Center for Democracy at the University of South Dakota \| South Dakota News Watch	12–Oct 14, 2026	500	likely voters	Republican 56 Independent and others 37	See the poll
Concord Public Opinion Partners Education Reform Now Advocacy	6–Oct 8, 2026	400	likely voters	Independent and others 43 Republican 42	See the poll
Zenith Research	24–Sep 27, 2026	500	likely voters	Republican 53 Independent and others 47	See the poll
Public Policy Polling	8–Sep 9, 2026	629	registered voters	Republican 45 Independent and others 42	See the poll
Lake Research Partners	26–Aug 30, 2026	500	likely voters	Independent and others 51 Republican 41	See the poll
Impact Research	13–Aug 17, 2026	500	likely voters	Republican 44 Independent and others 44	See the poll
Public Opinion Strategies National Republican Senatorial Committee	6–Jul 9, 2026	500	likely voters	Republican 56 Independent and others 33	See the poll
Public Policy Polling	29–May 30, 2026	726	registered voters	Republican 43 Independent and others 23 Democrat 18	See the poll
Public Policy Polling	17–Feb 18, 2026	685	registered voters	Republican 49 Democrat 32	See the poll
Public Policy Polling	13–Nov 14, 2025	814	registered voters	Republican 52 Democrat 30	See the poll
Public Policy Polling	30–Jul 31, 2025	552	registered voters	Republican 41 Independent and others 28	See the poll

Each poll as the pollster published it; these are not the Vote-Scope projection. When a pollster tests several ballots (with or without a given candidate), each one is shown as a scenario.

Current member

Mike Rounds · Republican

Primary results

Held June 2, 2026 · Official source

Republican primary	Mike Rounds	75.8%	101,284 votes

Who's running

The candidates

Candidates for the upcoming election.

Republican Incumbent

Mike Rounds
source
Other Challenger

Bengs, Brian

General-election qualification remains to be verified.

Other races in the region

Party ahead and how sure the projection is.

Alaska Democrat, toss-up
Alabama Republican, safe seat
Arkansas Republican, safe seat
Colorado Democrat, safe seat
Delaware Democrat, safe seat
Georgia Democrat, competitive

Watch list

The tightest races

The smallest projected gaps between the top two.

Forecast updated: November 2, 2026