# 2026 US Senate independent candidate challenges > Developing situation record from CLSTR: https://clstr.news/situations/2026-us-senate-independent-candidate-challenges > Updated: 2026-10-29T13:29:43.000Z. Sources: 2. Developments: 2. In the 2026 election cycle, independent candidates have emerged as significant challengers to Republican incumbents in several Senate races. In South Dakota, the race between Republican incumbent Mike Rounds and independent Brian Bengs has seen substantial financial activity. Early reports indicated a surge in Republican-aligned spending, with weekly expenditures for Rounds rising from under $18,000 to over $285,000 in late September. While initial polling showed a close race within the margin of error, Bengs later secured nearly $10 million in funding for his campaign, supported by the Forward Party. Bengs has focused his platform on political corruption and campaign-finance reform, while Republican opponents have characterized him as a liberal candidate. Similarly, in Nebraska, independent Dan Osborn has gained ground against Republican incumbent Pete Ricketts. Once viewed as a secure Republican seat, the race has become more competitive following endorsements from labor groups and the Nebraska Democratic Party. ## Timeline ### 2026-10-29: Independent candidates challenge incumbents in 2026 Senate races Independent candidates Brian Bengs in South Dakota and Dan Osborn in Nebraska are mounting competitive challenges against Republican Senate incumbents in the 2026 election cycle. 2 sources. https://clstr.news/cluster/independent-candidates-challenge-incumbents-in-2026-senate-races ### 2026-10-12: South Dakota Senate race sees surge in Republican campaign spending Republican spending has surged in South Dakota’s Senate race, with nearly $1.2 million supporting Mike Rounds as he faces a close contest against independent candidate Brian Bengs. 3 sources. https://clstr.news/cluster/south-dakota-senate-race-sees-surge-in-republican-campaign-spending --- Cite as: 2026 US Senate independent candidate challenges. CLSTR, https://clstr.news/situations/2026-us-senate-independent-candidate-challenges