The tight May 26 runoff between incumbent Senator John Cornyn and Attorney General Ken Paxton, following a March primary that drew roughly 2.17 million Republican votes, drives trader focus on turnout in the 1.2–1.5 million range. Recent University of Houston polling shows a statistical tie at 48–45 percent with only 7 percent undecided, prompting both campaigns to intensify base mobilization through heavy negative advertising and targeted outreach. Historical runoff patterns typically produce 30–50 percent drops from initial primaries, yet the high-profile contest and entrenched voter loyalty—evident in strong retention of first-round support—suggest participation will exceed typical mid-cycle levels while remaining below the March total. Key differentiators include Paxton’s stronger hold on his coalition versus Cornyn’s efforts to consolidate remaining moderates, with turnout hinging on which side more effectively converts likely voters in the final weeks.