Rep. Kevin Hern dominates trader consensus at 88.5% implied probability to win Oklahoma's Republican U.S. Senate primary, driven by his January 2025 campaign launch as a Trump-aligned challenger highlighting incumbent Sen. James Lankford's controversial bipartisan border security vote from earlier in the year. Hern's early fundraising success—over $2 million raised in the first quarter—and endorsements from conservative groups have solidified his frontrunner status, while other candidates like John M. O’Connor and Nick Hankins trail far behind with minimal polling support or visibility. No major shifts in the past week, though the June 2026 primary filing deadline could introduce new entrants; late scandals or Lankford's counter-mobilization remain low-probability risks to Hern's lead.