Methodology — Error-Weighted Multi-Source Average

All figures are averages across three major polling aggregators: RealClearPolitics (RCP), Silver Bulletin (Nate Silver/538), and Decision Desk HQ (DDHQ). These aggregators themselves incorporate polls from Gallup, Reuters/Ipsos, Quinnipiac, Emerson, Morning Consult, Economist/YouGov, Marist/NPR, Rasmussen, and dozens more. Each aggregator is weighted by its historical accuracy: sources that missed past election results by wider margins get less weight, and known house effects (systematic partisan lean) are adjusted before averaging. The same historical-error assumptions feed the Monte Carlo simulations on the Senate and House pages.