Dan Koh defeated Beth Andres-Beck, John Beccia, Tram Nguyen, and Jamie Zahlaway Belsito in the Democratic primary for Massachusetts' 6th Congressional District on Sept. 1. Incumbent Seth Moulton (D) ran for the U.S. Senate to represent Massachusetts.
Central to the election were the candidates' policies to address affordability, how they would oppose President Donald Trump's (R) administration, and whether their experience in or outside of politics and Washington, D.C., qualified them for Congress. Zahlaway Belsito and Koh had experience in Washington, D.C., and argued that their understanding of the federal system would benefit the district. Nguyen, a state legislator, said she was the only candidate with current legislative experience. According to The Boston Globe, Andres-Beck and Beccia argued that their non-political backgrounds would provide "fresh, outside perspectives to Capitol Hill."
In coverage of a June 2026 candidate debate, The Boston Globe's Anjali Huynh wrote, "Candidates offered similar, if not identical, messages in different fonts throughout the night, making it feel more like a collaborative policy discussion than a contentious debate." On affordability, Nguyen emphasized worker protections, Beccia middle-class tax relief, Koh housing and child care costs, Zahlaway Belsito reversing tariffs, and Andres-Beck education and energy prices.
