Senator Ed Markey won the Democratic primary for the United States Senate in Massachusetts on Tuesday, September 1, 2026, defeating U.S. Representative Seth Moulton. Markey, 80 years old, secured approximately 64.5% of the vote, translating to 431,166 ballots, compared to Moulton's 35.5%, or 237,028 votes, based on election returns covering 74% of precincts.
Markey, seeking a third full term in the Senate, will face Republican John Deaton in the November general election. Deaton ran unopposed in the Republican primary. In his victory speech, Markey attributed his success to grassroots organizing. Tonight is a testament to the power of the progressive movement of our nation, Markey stated. He outlined his legislative priorities, pledging to advance Medicare for All, the Green New Deal, policies targeting billionaire wealth, and measures to restrict funding for unauthorized military actions abroad.
Generational Debate and Primary Dynamics
Representative Seth Moulton, 47, based his primary campaign on the necessity of generational change within the Democratic Party. People ought to ask, what are you going to accomplish in the next six years that you haven't been able to accomplish in the last 50, Moulton argued during the campaign. Moulton faced internal pushback from progressive voters over his moderate stances on healthcare reform and past criticisms directed at Democrats supporting transgender athletes in competitive sports.
Markey's primary victory reflects broader national tensions within the Democratic Party during the 2026 election cycle, which has frequently pitted long-serving progressive incumbents against younger moderate challengers. Markey previously navigated a similar intra-party contest when he defeated then-Representative Joe Kennedy III in the 2020 primary by mobilizing younger climate-focused voters.
Additional Massachusetts Primary Outcomes
Beyond the Senate race, Massachusetts primary voters decided several congressional and executive nominations. In the gubernatorial contest, Mike Minogue won the Republican nomination and is scheduled to face incumbent Governor Maura Healey in November, per state election board returns.
In congressional races, Representative Katherine Clark secured the Democratic nomination for Massachusetts' 5th U.S. House District. Dan Koh won the Democratic nomination to succeed Moulton in the 6th Congressional District seat. Incumbent Stephen Lynch won the Democratic primary for Massachusetts' 8th Congressional District.
Final certified vote counts across all municipal districts remain subject to completion by the Massachusetts Secretary of the Commonwealth as outstanding mail-in ballots are tabulated.
General Election Outlook in Massachusetts
For Massachusetts voters, Markey's nomination establishes a clear ideological contest against Republican nominee John Deaton in November. Given the state's predominantly Democratic voter registration base, Markey enters the general election cycle as the heavily favored candidate.
Nationally, Markey's decisive primary margin reinforces the electoral viability of the progressive wing within the Democratic Party across northeastern urban centers, even as older incumbents face competitive primary challenges in other regions.
