NEW: Sen. Darline Graham thanks President Trump for his support as she heads to a runoff for a full term in South Carolina: "I want to thank President Trump fo

NEW: Sen. Darline Graham thanks President Trump for his support as she heads to a runoff for a full term in South Carolina: "I want to thank President Trump for his steadfast support and his complete and total endorsement means so much to me." "He knows that I will stand with him and fight for his…