Voters will decide Massachusetts Question 3 on November 3, 2026, which would replace separate party primaries for state offices with a single all-party primary where the top two advance to the general election starting in 2028. Trader sentiment remains closely balanced around the current 53.5% implied probability for rejection because both Democratic and Republican party organizations oppose the change, citing risks of reduced party influence, lower general-election turnout, and greater donor influence, while a coalition of moderate legislators and reform advocates argue it would broaden candidate appeal and competition in a heavily Democratic state. A late-September University of New Hampshire poll showed 41% support, 39% opposition, and 19% undecided, underscoring the role of undecided voters and campaign intensity in the final weeks. Key factors that could shift odds include new polling trends, high-profile endorsements, turnout patterns on Election Day, or voter reactions to the measure’s interaction with other ballot questions.