Dan Koh maintains a dominant position in the Massachusetts 6th Congressional District Democratic primary race as the September 1 primary approaches, reflecting trader consensus around his structural advantages in a crowded field. His campaign has raised over $3.5 million, a record for any Massachusetts U.S. House candidate, with broad donor participation across the district and multiple labor union endorsements including the IBEW. Koh was the first candidate to qualify for the ballot by securing the required signatures and has received high-profile support from former President Joe Biden in early May along with other local and statewide backers. An early March poll showed him leading with 42 percent support among likely primary voters amid a fragmented field of more than ten candidates. No other contender has consolidated comparable resources or visibility, though the four-month timeline leaves room for shifts ahead of the vote.