Nikki Gronli holds a trader consensus lead at 52.5% implied probability for the South Dakota At-Large Democratic primary, propelled by a May poll from South Dakota News Watch showing her at 41%—more than double Scott Schlagel's 13%—along with EMILY's List endorsement and top fundraising of over $250,000 as reported in recent FEC filings. Schlagel, a Navy veteran and entrepreneur, maintains second place at 10.5% on his military service and local business profile, while Billy Mawhiney sits at 2% amid limited visibility. With the June 4 primary nearing and early voting open, turnout among sparse Democratic voters in the deep-red state remains a key uncertainty for this open-seat contest.