Former Pinal County Sheriff Mark Lamb leads the Republican primary for Arizona’s 5th Congressional District as the open-seat contest heads toward the July 21 ballot. Lamb’s late 2025 entry, prior Senate run, and law-enforcement profile quickly positioned him ahead of remaining challengers Daniel Keenan and lower-profile candidates. Trader pricing reflects this edge while incorporating recent reporting on allegations of misconduct that have introduced uncertainty and narrowed his advantage. Jay Feely and Travis Grantham register minimal shares after limited traction and reports of withdrawals or shifts to other races. Club for Growth endorsement and early polling advantages for Lamb continue to anchor consensus, though the abbreviated campaign window and any further developments could still shift positioning before primary day.