Overview

• Rep. Seth Moulton, 46, formally entered the 2026 Democratic primary against Sen. Ed Markey with a launch video arguing the party needs new leadership and that Markey should not seek another term at 80.
• Moulton said he will focus on affordability, universal health care, banning assault weapons, fighting climate change and protecting democracy, highlighting his Marine service and work on the 988 crisis line and high‑speed rail proposals.
• Markey, 79, a longtime progressive who co-authored the Green New Deal, is consolidating support with endorsements that include the Mass. Nurses Association, the League of Conservation Voters Action Fund, key state legislative leaders and Sen. Elizabeth Warren.
• An Advantage/Fiscal Alliance Foundation poll from late September showed Moulton leading in a hypothetical matchup, 43%–21% among likely voters and 38%–30% among Democrats, though many respondents were undecided and the polling is early.
• The Democratic primary is set for Sept. 1, 2026, in a state where the primary winner is heavily favored in November, and Moulton’s past comments on transgender athletes present a potential liability as the campaign begins.