Ken Paxton defeats four-term Senator John Cornyn in Texas Republican primary by nearly two to one, signaling Trump's continued sway over GOP races and setting up a competitive Senate contest. South Carolina Republicans block Trump's redistricting push, citing concerns it energizes Democratic voters. Meanwhile, Trump claims Iran deal progress for the sixth time with no agreement reached, complicating negotiations by pushing Gulf countries to join Abraham Accords. Ken Paxton's 2-to-1 victory over John Cornyn demonstrates Trump's endorsement remains the most powerful force in Republican primary politics, even when given late in campaigns.