The tight clustering of probabilities around the 115-130 million vote range for the 2026 House midterms reflects competing turnout dynamics in a contest viewed as a referendum on the Trump administration. Democratic-leaning mobilization efforts, including targeted outreach to lower-propensity Black, young, and rural voters, alongside structural factors such as expanded mail and early voting options, support expectations near or above recent midterm highs like 2018. Offsetting pressures include Republican base engagement initiatives, economic concerns weighing on participation, and typical midterm drop-off from presidential-year levels. With generic ballot leads favoring Democrats and primary signals showing uneven enthusiasm, traders see limited separation until late-cycle polling and registration data clarify net mobilization effects ahead of November 3.