# South Dakota U.S. Senate 2026 ## Snapshot **Settled June 2: [[Mike Rounds]] (R) vs. [[Julian Beaudion]] (D) — and independent [[Brian Bengs]], who is the one actually polling close.** Rounds beat Navy veteran Justin McNeal roughly 76–24 in the Republican primary (no runoff; the 35% threshold was never in play). Beaudion, a former Highway Patrol trooper endorsed by Joe Biden on June 5, was unopposed for the Democratic nomination. Bengs — the 2022 Democratic nominee, now running unaffiliated — polls at 40% head-to-head against Rounds (PPP, May) versus Beaudion's 31%, which is why Race to the WH and The Economist carry the race at Likely R while Cook, Sabato and Inside Elections hold Solid/Safe R. No Republican has lost a South Dakota Senate race since 2008. ## Incumbent - **[[Mike Rounds]]** (R) — senator since 2015, seeking a third term; governor 2003–2011. Trump-endorsed (July 2025) after helping deliver Republican votes on the public-media rescission — the endorsement was explicitly transactional. $3.98M raised, $2.66M cash on hand through May 13. ## How the nominations were decided (June 2, 2026) ### Republican primary | Candidate | Votes | % | |---|---|---| | **Mike Rounds** | 101,471 | **75.8** | | Justin McNeal | 32,412 | 24.2 | (Exact figures are Wikipedia-final; KOTA and 270toWin confirm the win without percentages.) ### Democratic primary - **[[Julian Beaudion]]** — unopposed. Former state trooper, activist and businessman. ## General election — three candidates - **[[Mike Rounds]]** (R) - **[[Julian Beaudion]]** (D) — $210K raised, $3K cash on hand through May 13. - **[[Brian Bengs]]** (I) — Navy and Air Force veteran, former Northern State University political-science professor, the 2022 Democratic nominee (lost to Thune 70–26). $666K raised, $58K cash on hand. | PPP, May 29–30, 2026 (726 RV, ±3.6) | Rounds | Bengs | Beaudion | |---|---|---|---| | Three-way | 43 | 23 | 18 | | Rounds vs. Bengs | 44 | 40 | — | | Rounds vs. Beaudion | 56 | — | 31 | ## Ratings history - Cook Solid R (Apr 13) · Inside Elections Solid R (Apr 23) · Sabato Safe R (Mar 4) · Race to the WH and The Economist **Likely R** (May 22) — the softest ratings anywhere on the five-state safe-R block, attributable to Bengs. ## Key dates - 2026-06-02 — primaries (held) - 2026-11-03 — general election ## Intel notes - **South Dakota is the third 2026 test of the independent-lane theory**, after Montana (Democrat stayed in) and Idaho (Democrat left). Here the Democrat is a placeholder with $3,000 and the independent is the party's own last nominee — the closest thing to a Democrat-in-all-but-name running unaffiliated. The three-way number (Rounds 43, Bengs 23, Beaudion 18) shows the split; the two-way (44–40) shows the ceiling. Nobody is asking Beaudion to withdraw, and there is no deadline mechanism pushing him. - **The Trump endorsement transaction** — earned by delivering votes to defund public broadcasting — remains the cleanest 2026 example of an endorsement conditioned on a specific legislative act. - **Rounds–Thune**: both South Dakota senators in leadership ([[John Thune]] as Majority Leader) means the state's federal footprint runs through two offices with no daylight between them. ## Related KB entities - [[Mike Rounds]] · [[Julian Beaudion]] · [[Brian Bengs]] · [[John Thune]] - [[MAGA]] — the endorsement transaction - [[MT-Sen-2026]] · [[ID-Sen-2026]] — the other independent-lane races ## Content leads - **Blog**: "The Price of a Trump Endorsement" — Rounds and public media. - **Data**: three-way vs. two-way polling in MT/ID/SD — what the independent lane costs the Democrat. ## Sources - [KOTA — Rounds wins Republican primary (June 3, 2026)](https://www.kotatv.com/2026/06/03/mike-rounds-wins-republican-primary-south-dakota-us-senate-race/) - [South Dakota Searchlight — Rounds fends off primary challenger](https://southdakotasearchlight.com/briefs/us-sen-mike-rounds-of-south-dakota-fends-off-republican-primary-challenger/) - [Wikipedia — 2026 South Dakota Senate election](https://en.wikipedia.org/wiki/2026_United_States_Senate_election_in_South_Dakota) - [South Dakota Searchlight — Rounds wins Trump endorsement after public-media role](https://southdakotasearchlight.com/briefs/rounds-wins-trump-endorsement-after-playing-deal-making-role-in-rescinding-public-media-funds)