Incumbent Ed Markey’s commanding position in the Massachusetts Democratic Senate primary stems from sustained advantages in recent polling and broad support among core Democratic constituencies ahead of the September 1 vote. Multiple August surveys, including Suffolk University/Boston Globe and UMass Amherst/WCVB, showed Markey ahead of Seth Moulton by double digits after earlier contests narrowed, reflecting stronger trust on key issues, higher favorability among progressives and women, and effective grassroots organization. Moulton’s emphasis on generational turnover and Markey’s age has gained limited traction beyond moderates. Scenarios that could still narrow the gap include higher-than-expected turnout among Moulton’s base or shifts following the final debate, though trader pricing aligns with the incumbent’s consistent polling edge and institutional backing.