Massachusetts voters will decide the 2026 U.S. Senate race on November 3, with the Democratic primary set for September 1. Incumbent Ed Markey holds a consistent lead over primary challenger Seth Moulton in recent polling, though a sizable share of voters remain undecided. The state’s heavy Democratic registration advantage and voting history have produced large general-election margins in hypotheticals pitting Democrats against Republicans such as John Deaton. Trader consensus reflected in the 95.5% Democrat price aligns with these structural factors and the absence of competitive Republican infrastructure in recent cycles. A late primary upset producing a weaker nominee, an unforeseen scandal, or a major shift in turnout patterns could narrow the gap, though such developments would need to overcome entrenched partisan patterns to move the outcome.