Dan Koh's commanding fundraising advantage, with roughly $4.5 million raised and millions in cash reserves, has enabled sustained broadcast advertising that highlights his experience as former chief of staff to Boston's mayor and U.S. Labor Department officials, positioning him as the consensus leader ahead of the September 1 Democratic primary for the open Massachusetts 6th Congressional District seat. State Representative Tram Nguyen, the only current officeholder in the field, counters with biographical messaging as a Vietnamese refugee and public housing alum who has defeated Republican candidates locally, though she reached television later and with less spending. Recent candidate forums in early August have kept attention on the crowded field, but trader consensus reflected in current pricing attributes Koh's edge to resource disparities and name recognition in a race vacated by the incumbent seeking higher office.