Incumbent Ed Markey maintains a strong position heading into the September 1 Democratic primary, bolstered by his party endorsement win at the state convention in late May with nearly 73% delegate support. Ayanna Pressley’s March endorsement and other progressive backing have reinforced his base among Democratic voters. Seth Moulton has cleared the ballot threshold and gained some ground in spring polling, narrowing earlier gaps amid debates over age and generational change, yet he trails significantly in current trader pricing. Minor candidates including Alexander Rikleen register negligible support. Recent head-to-head exchanges, including a June 16 debate, have not materially shifted the consensus implied probability favoring Markey’s renomination.