Incumbent U.S. Senator Ed Markey defeated Representative Seth Moulton in the Massachusetts Democratic Senate primary on September 1, securing the party’s nomination for a third full term. The 80-year-old progressive fended off the 47-year-old centrist’s challenge with decisive support from grassroots Democrats, a result that reflects the state party’s preference for Markey’s experience and long record of advocacy.
Markey won with approximately 55% of the vote, while Moulton received roughly 45%, according to results reported by the Associated Press and multiple news outlets. The outcome delivered a clear mandate for the incumbent after months of campaigning in which Moulton argued it was time for younger leadership and a shift away from what he called the “status quo.”
The primary result echoed Markey’s 2020 victory over another younger challenger, then-Representative Joe Kennedy III. In that race, Markey mobilized grassroots support and progressive activists to overcome Kennedy’s establishment backing, winning 55% of the vote. According to reporting from the Washington Post, Markey used a similar playbook this year, appealing to younger left-wing leaders and emphasizing his decades-long progressive record on climate change, healthcare, and labor issues.
Polls leading into the primary showed Markey with commanding leads. A UMass Amherst/WCVB survey released in mid-August found Markey holding 60% support among likely Democratic primary voters compared to Moulton’s 32%, a 28-point advantage. According to UMass researchers cited in reporting from August 17, the incumbent carried an 82% job approval rating among Democratic voters, a figure that underscored his strength within the party base.
The race pitted a veteran progressive senator against a moderate congressman who sought to frame the election as a generational choice. Moulton, who served in the U.S. Marine Corps and has represented Massachusetts’s 6th Congressional District, argued that Markey’s age and long tenure made him out of touch with current priorities. Markey countered by highlighting his seniority on key Senate committees and his long advocacy for progressive causes, particularly climate action and workers’ rights.
Markey will now face Republican John Deaton in the November 3 general election. Deaton, a trial attorney and Marine veteran, ran unopposed in the Republican primary on the same day. According to polling from late August, Markey led Deaton by approximately 19 points in hypothetical general election matchups, suggesting a strong position heading into the fall campaign in the heavily Democratic state.
The Massachusetts Senate primary was one of several competitive races decided on September 1. Richard Neal defeated Jeromie Whalen in the 1st District primary, while Dan Koh won the House primary for the open 6th District seat. On the Republican side, Mike Minogue won the GOP primary, positioning himself to challenge Governor Maura Healey in November.
Sources
- Associated Press — confirmed Markey’s primary victory and final vote totals
- New York Times — reported on Markey’s win and his use of progressive messaging and younger activist support
- Washington Post — detailed Markey’s 2020 victory over Kennedy and his similar 2026 strategy
- NPR — characterized the race as a generational clash and noted Markey’s age advantage in winning
- UMass Amherst/WCVB — provided mid-August polling showing Markey’s 28-point lead and 82% job approval
- Ballotpedia — confirmed primary date, ages, and general election matchup details
- Al Jazeera — provided vote totals and background on the race
- CBS Boston — confirmed Markey’s advancement to the general election against Deaton
