Dan Koh Wins Democratic Primary for Massachusetts 6th District

Dan Koh, a former aide in the Biden administration, won a crowded Democratic primary on September 2, 2026, for Massachusetts' 6th Congressional District, positioning himself as the likely successor to Representative Seth Moulton. The Associated Press called the race, with Koh defeating five other candidates to secure the nomination in a district rated safely Democratic. Koh, who received 41.1% of the vote, defeated his nearest rival, state Representative Tram Nguyen, who garnered 29.5%. The remaining candidates each received less than 15%. In his victory speech, Koh reflected on his family's immigrant history, noting his Lebanese heritage and a grandmother who fled North Korea as a refugee. "I know that tonight, I stand on their shoulders," he told supporters. The primary was for the seat vacated by Moulton, a Marine Corps veteran who has represented the district since 2015. Moulton declined to seek reelection to instead challenge incumbent Senator Ed Markey in the Democratic Senate primary. Markey, 80, defeated Moulton, 47, who had campaigned on a message of generational change.