South Dakota Senate
Candidates
| Candidate | Party | Poll avg | Latest poll | Raised | Cash | Outside for / against |
|---|---|---|---|---|---|---|
| Mike Rounds incumbent | R | 53% (6) | 41% | $5.1M | $1.3M | $1.1M / — |
| Brian Bengs | I | 41.3% (6) | 43% | $1.9M | $70k | — |
Unweighted mean of the latest general-election poll from each of 6 pollsters since 2026-09-20.
Tracking the poll average daily since November 3, 2026; a chart appears after three days.
Polls 11 in the window
| Field dates | Pollster | Sample | Result | D − R |
|---|---|---|---|---|
| Oct 26 from Oct 22 | Concord Public Opinion Partners for Education Reform Now Advocacy D-sponsored | 448 LV | Brian Bengs I 43 · Mike Rounds R 41 | — |
| Oct 21 from Oct 19 | Emerson College for KELO-TV | 803 LV | Mike Rounds R 54 · Brian Bengs I 46 | — |
| Oct 19 from Oct 17 | Quantus Insights | 657 LV | Mike Rounds R 59.4 · Brian Bengs I 37.3 | — |
| Oct 16 from Oct 12 | Public Opinion Strategies R-sponsored | 500 LV | Mike Rounds R 54 · Brian Bengs I 37 | — |
| Oct 14 from Oct 12 | Mason-Dixon Polling & Research, Inc. for Chiesman Center for Democracy at the University of South Dakota | South Dakota News Watch | 500 LV | Mike Rounds R 56.4 · Brian Bengs I 37.4 | — |
| Oct 8 from Oct 6 | Concord Public Opinion Partners for Education Reform Now Advocacy D-sponsored | 400 LV | Brian Bengs I 43 · Mike Rounds R 42 | — |
| Sep 27 from Sep 24 | Zenith Research I-sponsored | 500 LV | Mike Rounds R 53 · Brian Bengs I 47 | — |
| Sep 9 from Sep 8 | Public Policy Polling I-sponsored | 629 RV | Mike Rounds R 45 · Brian Bengs I 42 | — |
| Aug 30 from Aug 26 | Lake Research Partners D-sponsored | 500 LV | Brian Bengs I 51 · Mike Rounds R 41 | — |
| Aug 17 from Aug 13 | Impact Research I-sponsored | 500 LV | Mike Rounds R 44 · Brian Bengs I 44 | — |
| Jul 9 from Jul 6 | Public Opinion Strategies for National Republican Senatorial Committee R-sponsored | 500 LV | Mike Rounds R 56 · Brian Bengs I 33 | — |
Money
FEC candidate committee totals for the 2026 cycle, through October 14, 2026. Outside for / against is Schedule E independent spending by other committees to support or oppose the candidate. Each figure links to the candidate's FEC page.
Platform ad spend
Meta's Ad Library Report, Google's Ads Transparency Center and Snap's political-ads library. An advertiser is tied to a candidate only when its name carries the candidate's surname together with this state or the candidate's full name; outside groups that do not name a candidate appear in the state and district totals, not here.
No advertiser on either platform names a candidate in this race.
Meta in South Dakota: $125k Oct 25, 2026 - Oct 31, 2026 · Google in South Dakota: $4.3M lifetime · Snap targeted at South Dakota: $15k in 2026.
All senate races → · The races hub → · JSON
Polls: PollResults.org (New York Times poll data), CC BY 4.0 (1,579 poll questions in the window). Money: FEC candidate totals and Schedule E independent-expenditure totals for the 2026 cycle. Platform ad spend: Meta Ad Library Report (U.S., 7-day preset, read from the report page), Google Ads Transparency Center CSV bundle and Snap political ads library, via Corvus Intel. Snapshot 2026-11-04 00:20 UTC, refreshed every six hours. No model wrote these figures, and no prediction-market price is used. Read how we work, or see the Politics desk for the analysis built on top of them. JSON.