The Fierce Fight for Seth Moulton’s Open Seat: Massachusetts 6th District Primary Heats Up

The political landscape in Massachusetts’ 6th Congressional District is buzzing with intense activity as a highly competitive Democratic primary unfolds to determine who will succeed Representative Seth Moulton. With Rep. Moulton set to challenge Senator Ed Markey, his decision has opened up a rare and coveted seat, drawing a significant number of ambitious hopefuls.

This race marks the first truly open contest for the 6th District since the 1990s, offering a unique opportunity for North Shore Democrats aspiring to advance to Washington. It’s also Massachusetts’ first open House primary since 2020, guaranteeing a fresh face in Congress for this solidly blue district.

Dan Koh Dominates Early Fundraising in Massachusetts 6th District Primary

Among the contenders, Dan Koh, a seasoned political operative and former aide to President Joe Biden and US Labor Secretary Marty Walsh, has emerged as an early financial powerhouse. Since launching his campaign for the 6th District contest on October 16, Koh has impressively raised over $2 million.

His campaign proudly asserts this sum is a record-breaking haul for any Massachusetts House candidate in history. Koh’s financial prowess is not new; he was also a prolific fundraiser during his 2018 bid for Massachusetts’ 3rd District, where he narrowly lost to Representative Lori Trahan after a recount.

The support for Koh is broad, with his campaign reporting a median contribution of $50 from donors across every city and town in the North Shore-based district. Notable Democratic figures, including Marty Walsh, former US Secretary of Energy Jennifer Granholm, and former Governor Deval Patrick, are among his supporters. Koh has also garnered endorsements from high-profile national Democrats, like former Vice President Kamala Harris, along with local officials and key labor unions such as the International Brotherhood of Electrical Workers 103.

“The response to this campaign shows that people want leaders who are willing to do the work, listen first, and fight hard to get results,” Koh stated, emphasizing his campaign’s momentum.

A Crowded Field Emerges for the Open Congressional Seat

While Koh has an early financial lead, he is not alone in the pursuit of Seth Moulton’s open seat. Several other notable Democrats have entered the race, many of whom have demonstrated their capability to raise significant funds:

• John Beccia: A cryptocurrency lawyer from Lynnfield, Beccia’s campaign announced it has $1 million on hand, a mix of fundraising and self-funding. “This campaign has real momentum and we’re just getting started,” Beccia commented.
• Beth Andres-Beck: A software engineer, Andres-Beck’s campaign emphasized its grassroots nature, reporting over 4,100 contributions with an average of $21.62. She raised over $108,000 in the third quarter of 2025, with $25,000 self-funded.
• Rick Jakious: Rep. Moulton’s former chief of staff, Jakious has raised nearly $300,000 by “listening to voters in all 39 communities, not courting Washington insiders.”
• Jamie Belsito & Tram Nguyen: Topsfield town moderator and former state representative Jamie Belsito, and state representative Tram Nguyen, are also in the running, though their initial fundraising figures were not immediately available.

Most candidates declared their intention to run for the 6th District race in the two weeks following Moulton’s Senate challenge announcement on October 15, highlighting the immediate interest in this rare opportunity. The first full fundraising quarter for the race will conclude between January and March of 2026, setting the stage for more detailed financial disclosures.

Why This Race Matters: A Pivotal Moment for Massachusetts Politics

The departure of Rep. Seth Moulton creates a vacuum that is attracting diverse candidates eager to represent the 6th District. This congressional primary is more than just a local election; it’s a barometer of Democratic priorities and grassroots energy in Massachusetts. The eventual winner will step into a significant role on Capitol Hill, representing a vibrant and politically engaged constituency. Understanding the dynamics of primary elections and the role of a U.S. Representative can shed more light on the stakes involved.

As the September 1 primary approaches, the competition is expected to intensify, with candidates ramping up their efforts to connect with voters and solidify their support. The battle for the 6th District promises to be one of the most compelling political stories in Massachusetts, showcasing a blend of experienced political figures and fresh faces vying for a chance to serve in the U.S. House of Representatives.