Michael Katz holds a strong lead in the Delaware Republican U.S. Senate primary, scheduled for September 15, 2026, reflecting trader consensus on his party endorsement and prior elected experience in the state Senate. Katz, who previously served as a Democrat and ran as an independent in the 2024 Senate race, switched to the Republican Party earlier this year and secured the official endorsement, providing a clear organizational advantage over challenger John Shulli. Shulli, an Army veteran and former Pentagon instructor with limited prior elected experience in Delaware, has raised more campaign funds but lacks comparable name recognition or institutional support. No major new developments have emerged in recent weeks to shift the positioning ahead of the primary vote.