Michael Katz holds a strong lead in the Delaware Republican Senate primary due to his endorsement by the state Republican Party, an 82% victory at the April 2026 state convention, and backing from multiple legislators and former U.S. Attorney Julianne Murray. His background as a former state senator, physician, and business owner supports arguments for broader general-election appeal against Democrat Chris Coons in the heavily Democratic state. Katz also maintains a fundraising edge with greater cash on hand. John Shulli, a retired Army colonel and War College instructor endorsed by Michael Flynn, emphasizes military and national security experience but trails in organizational support. The September 15 primary occurs in two days, with trader consensus reflecting Katz’s consolidated advantages heading into voting.