Incumbent Senator Lindsey Graham holds a dominant position in the South Carolina Republican Senate primary, reflecting his long tenure, substantial fundraising advantage, and President Trump's endorsement. Recent polling from mid-May shows Graham at 56 percent among likely voters, well above the majority threshold needed to avoid a June 23 runoff, while nearest challenger Mark Lynch stands at 13 percent and remaining candidates remain in single digits. Paul Dans's April withdrawal and endorsement of Lynch have not narrowed the gap. With the primary scheduled for June 9, trader consensus on Graham's frontrunner status aligns with these structural factors and historical patterns for well-funded incumbents in safe Republican states, though unexpectedly low base turnout or major late developments could still create narrow openings for challengers.