In the Delaware Republican U.S. Senate primary set for September 15, 2026, trader consensus gives Michael Katz a narrow 45% implied probability over John Shulli's 38.5%, driven by Katz's April 27 endorsement at the state GOP convention, which mobilized party delegates and infrastructure in this low-turnout contest. The race remains tightly contested amid Shulli's advantages in fundraising—$100,729 raised versus Katz's $20,211 as of late March—and his extensive military credentials as an Army Reserves colonel and retired DoD policy analyst. Absent polls, separation could come from national endorsements, upcoming FEC quarterly reports, debates, or advertising in the coming months, with Delaware's small Republican primary electorate sensitive to turnout and ground game.