Dan Koh leads the Democratic primary for Massachusetts’s open 6th congressional district with trader consensus reflecting his substantial fundraising advantage—over $3.5 million raised—and early ballot access as the first candidate to qualify. The September 1 primary features a fragmented field including state Representative Tram Nguyen, who has shown competitive polling in some surveys amid high undecided rates. Koh’s prior congressional bid and endorsements from local officials and unions provide structural edges in a race vacated by Representative Seth Moulton’s Senate challenge. Recent internal polls indicate no candidate has consolidated support, yet Koh’s resource lead sustains his market positioning ahead of the September contest.