Michael Katz holds an 82.5% implied probability in the Delaware Republican Senate primary market, driven primarily by his endorsement from the state Republican Party following his switch from prior Democratic and independent affiliations. This institutional backing, combined with established name recognition from earlier statewide runs, has consolidated early support ahead of the September 15, 2026 primary. John Shulli trails at 17%, reflecting his stronger recent fundraising totals and military credentials as an Army colonel and War College instructor, yet limited party infrastructure. No major polling or additional endorsements have shifted the consensus since candidate filings stabilized, leaving Katz positioned as the consensus frontrunner absent late developments.