Michael Katz holds an 80.5% implied probability in the Delaware Republican Senate primary due to his formal endorsement by the state Republican Party at its convention, along with prior experience as a Democratic state senator and the party's 2024 Independent U.S. Senate nominee. John Shulli trails at 15.5% despite stronger early fundraising and a 28-year military career that includes service as a U.S. Army War College instructor and roles in defense policy. The September 15, 2026 primary remains months away with limited additional polling or major endorsements reported, leaving room for shifts from further candidate outreach or turnout dynamics in this low-visibility contest.