Toby Doeden leads trader consensus in South Dakota’s Republican gubernatorial primary due to recent polling momentum and heavy self-funding that increased his visibility among likely voters ahead of the June 2 vote. Late May surveys from Emerson College and Meeting Street Insights showed Doeden edging or tying U.S. Rep. Dusty Johnson, with Gov. Larry Rhoden and House Speaker Jon Hansen further back in multi-candidate fields. Doeden’s outsider business background and substantial ad spending contrast with Johnson’s established congressional record and Rhoden’s status as the incumbent elevated from lieutenant governor in 2025. The tight polling and high campaign expenditures underscore the competitive dynamics entering primary day.