Incumbent Lindsey Graham leads trader consensus at 81% implied probability for the South Carolina Republican Senate primary on June 9, buoyed by his fundraising dominance—over $19 million raised—longstanding incumbency advantages, and President Trump's recent endorsement praising him as a key ally while criticizing challenger Mark Lynch. Early primary polls, such as Quantus Insights showing Graham at 58% versus Lynch's 15%, underscore his edge among GOP voters despite high unfavorable ratings around 61% statewide. Paul Dans' April 10 campaign exit and endorsement of Lynch elevated the business owner's share to 13.4%, consolidating some anti-incumbent support, while retired Navy veteran Thomas Murphy lingers at 0.2% amid a fragmented field of 12 GOP contenders. Upcoming debates or further endorsements could shift dynamics in this low-turnout primary.