Michael Katz holds a commanding lead in the Delaware Republican U.S. Senate primary, scheduled for September 15, 2026, due to securing the state party's endorsement and his prior elected experience in the Delaware State Senate. Traders view this institutional backing as a decisive advantage in a low-profile contest against John Shulli, an Army veteran and former Pentagon official who filed earlier in the cycle but lacks comparable party support. Recent candidate filings and the party's July announcement reinforced Katz's position, with no major shifts in endorsements, polling, or campaign events reported in the past month that would alter the implied probabilities. The primary's proximity leaves limited room for late developments to close the gap.