Incumbent Sen. Lindsey Graham commands 81% trader consensus in the South Carolina Republican Senate primary due to his overwhelming fundraising lead—over $13 million cash on hand—high-profile endorsements from President Trump, Gov. Henry McMaster, and Sen. Tim Scott, and entrenched name recognition in the GOP stronghold. Paul Dans' withdrawal last week and endorsement of Mark Lynch consolidated anti-incumbent support, elevating Lynch to 13.7% amid an America First challenge criticizing Graham's foreign policy. March polls showed Graham at 41%—below the 50% threshold to avoid a June 23 runoff—but traders discount challenger-sponsored surveys, factoring Lynch's prior felony conviction and fragmented field including minor candidates like Thomas Murphy at 0.2%. The June 9 primary looms as the key test.