Roger Marshall holds an 80% implied probability of carrying Leavenworth County in the 2026 Kansas Senate race, while Adam Hamilton sits at 20.5%, reflecting the county’s Republican-leaning electorate amid a competitive statewide contest. Marshall benefits from incumbency, Trump endorsement, and consistent strength in military-influenced and rural-adjacent areas like Leavenworth, even as statewide polls show Hamilton within a few points through mid-October. Hamilton’s crossover appeal, recent fundraising edge, and endorsements from former Republican governors have tightened the overall race but have not shifted expectations enough to make a county flip likely. Upcoming events including the October 21 debate and final voter turnout in this Kansas City metro county remain the primary variables that could alter county-level margins before November 3.