Dan Koh secured the Democratic nomination in September’s primary for the open Massachusetts 6th District seat after Seth Moulton pursued a Senate bid, defeating a crowded field that included state Rep. Tram Nguyen. The district’s consistent Democratic lean—reflected in prior presidential margins exceeding 20 points and ratings as Solid or Safe Democratic—combined with Koh’s fundraising edge exceeding $5 million versus Micah Jones’s roughly $600,000, anchors trader consensus on an overwhelming victory. Jones, an unopposed Republican nominee and Army veteran, faces structural barriers typical of the North Shore district. Late developments such as an unforeseen scandal, health issue, or turnout surge remain the narrow paths that could alter the November 3 outcome.