Incumbent Sen. Ed Markey's commanding position in the Massachusetts Democratic Senate primary stems from his strong incumbency advantage and recent polling dominance, reflected in trader consensus pricing him at 82.5% to win the September 1 nomination. A Suffolk University/Boston Globe poll from April 9-13 showed Markey leading Rep. Seth Moulton 47%-30% among likely Democratic primary voters, with 20% undecided and Markey's favorability at +75 (84%-9%), widening his edge from February's 35%-23% margin. Moulton, who launched his generational change-focused challenge in October 2025, trails but holds second at 14% on markets. Rep. Ayanna Pressley declined entry in December 2025, while Alexander Rikleen lingers as a fringe contender at 0.3%. High name recognition and progressive record bolster Markey ahead of the summer campaign sprint.