South Dakota

Brian Bengs (I)vsMike Rounds (R)

incumbent running · Cook: Solid R · Sabato: Safe R · Inside Elections: Solid R

9 in 10

Mike Rounds favored93%

Very likely for Mike Rounds: a 93 percent chance of winning. Polls: Mike Rounds up 3.8.

Seat:Incumbent running
Cook:Solid R
Sabato:Safe R
Inside Elections:Solid R
Odds:Rounds 93%
Margin:Rounds +10.4, give or take 6.0
Polls:9, averaging Rounds +3.8
Latest poll:Zenith Research, Sep 27, Rounds +6.0
Generic ballot:D+8.2
T-minus:16 days

▸ Margin // Uncertainty

Rounds +10.4

The model's best guess at the final margin, give or take 6.0 points. Polls have missed by more than that before.

Projected margin: Rounds +10.4
Uncertainty: 6.0 points, one standard deviation
Likely range: Rounds +18.0 to Rounds +2.8 (80 percent)
Poll average: Rounds +3.8 across 9 polls, worth 0.3 fresh polls after weighting
Starting point: Rounds +22.5 before any polls, give or take 10.0

How polls have done here
8 Senate races here since 1998: the final polls missed by 7.0 points on average, on balance underrating Democrats. Last time, 2022, they were off by 12.5 toward Democrats.

Margins read Democrat minus Republican: Bengs ahead is positive, Rounds ahead is negative.

▸ Movement // 0 daily snapshots

Reading the history

▸ Polls // 9 public polls

Zenith ResearchRounds +6
Sep 27 · unrated · 500 LV47 to 53 · 72% weight
Independent sponsor
Public Policy PollingRounds +3
Sep 09 · B+ · 629 RV42 to 45 · 17% weight
Independent sponsoradjusted Even
Lake Research PartnersBengs +10
Aug 30 · A/B · 500 LV51 to 41 · 6% weight
Democratic sponsoradjusted Bengs +7.0
Impact ResearchTie
Aug 17 · B/C · 500 LV44 to 44 · 6% weight
Independent sponsoradjusted Bengs +1.1
Public Opinion StrategiesRounds +23
Jul 09 · A · 500 LV33 to 56 · 0% weight
Republican sponsoradjusted Rounds +20.0
Public Policy PollingRounds +20
May 30 · B+ · 726 RV23 to 43 · 0% weight
Independent sponsoradjusted Rounds +17.0
Public Policy PollingRounds +12
Feb 18 · B+ · 685 RV35 to 47 · 0% weight
Independent sponsoradjusted Rounds +9.0
Public Policy PollingRounds +13
Nov 14 · B+ · 814 RV31 to 44 · 0% weight
Independent sponsoradjusted Rounds +10.0
Public Policy PollingRounds +13
Jul 31 · B+ · 552 RV28 to 41 · 0% weight
Independent sponsoradjusted Rounds +10.0

Pollster	Grade	Date	Sample	Result	Weight
Zenith ResearchIndependent sponsor	unrated	Sep 27	500LV	Rounds +647 to 53	72%
Public Policy PollingIndependent sponsor	B+	Sep 09	629RV	Rounds +342 to 45adjusted Even	17%
Lake Research PartnersDemocratic sponsor	A/B	Aug 30	500LV	Bengs +1051 to 41adjusted Bengs +7.0	6%
Impact ResearchIndependent sponsor	B/C	Aug 17	500LV	Tie44 to 44adjusted Bengs +1.1	6%
Public Opinion StrategiesRepublican sponsor	A	Jul 09	500LV	Rounds +2333 to 56adjusted Rounds +20.0	0%
Public Policy PollingIndependent sponsor	B+	May 30	726RV	Rounds +2023 to 43adjusted Rounds +17.0	0%
Public Policy PollingIndependent sponsor	B+	Feb 18	685RV	Rounds +1235 to 47adjusted Rounds +9.0	0%
Public Policy PollingIndependent sponsor	B+	Nov 14	814RV	Rounds +1331 to 44adjusted Rounds +10.0	0%
Public Policy PollingIndependent sponsor	B+	Jul 31	552RV	Rounds +1328 to 41adjusted Rounds +10.0	0%

Weight is each poll's share of the average, in percent, after recency, sample size, pollster grade and sponsorship are taken into account. The shares add to 100. Adjusted margins remove the pollster's usual lean. Grades are Silver Bulletin's.

▸ Race file // The facts

The seat: Mike Rounds (R), running for another term.
On the ballot: Brian Bengs (I) vs Mike Rounds (R, incumbent)
Last time: 2020: Mike Rounds (R) 65.7, Dan Ahlers (D) 34.3. Rounds by 31.4.
President: 2024, statewide: Trump 63.4, Harris 34.2. Trump by 29.2.
The raters: Cook Solid R · Sabato Safe R · Inside Elections Solid R

Facts from Ballotpedia and Wikipedia, in our words. The race on Ballotpedia ↗

▸ Candidates // Read more

Independent
Brian Bengs
Bengs on Ballotpedia ↗
Republican
Mike Rounds
Rounds on Ballotpedia ↗

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