Dan Koh leads the MA-06 Democratic primary market at 71.5% due to his substantial fundraising edge—nearly $3.5 million raised—and endorsements from former President Biden along with local officials and labor groups. As a former White House official and repeat congressional candidate who qualified first on the ballot, Koh benefits from name recognition in a fragmented field ahead of the September 1 primary. State Rep. Tram Nguyen trails at 13.2% with strong local support and recent internal polling around 13%, while John Beccia and others remain in single digits amid high undecided rates of 46% or more in May surveys. The race features seven Democratic contenders following Rep. Seth Moulton’s Senate bid, with trader consensus reflecting Koh’s resource and organizational advantages in the crowded contest.