Ed Markey maintains a strong position in the Massachusetts Democratic Senate primary due to his long incumbency and established support among party voters, though recent polling has narrowed his edge over challenger Seth Moulton. A May 2026 Emerson College survey showed Markey leading Moulton 37% to 32% among likely primary voters, with 29% still undecided, tightening from wider margins in earlier April polls. Moulton has emphasized generational leadership change and broader Democratic renewal as key campaign themes. Minor candidates including Ayanna Pressley and Alexander Rikleen register negligible support in available surveys. Traders appear to weigh Markey’s name recognition and historical primary resilience against Moulton’s momentum from the latest data, with the September primary still months away.