Seth Moulton Gains Ground on Ed Markey in Massachusetts Senate Primary

In a significant shift from previous polling, the Massachusetts Democratic Senate primary race has tightened considerably, with challenger Rep. Seth Moulton closing the gap against incumbent Sen. Ed Markey. A new Emerson College poll shows Markey with just a 5-point lead over Moulton, 37% to 32%, with a substantial 29% of voters still undecided.

This represents a dramatic change from just last month when a Suffolk University/Boston Globe poll had Markey comfortably ahead by 17 points, 47% to 30%. Previous polls had shown Markey leading by as much as 20 points in what has become one of the most closely watched primary contests in the nation.

The 79-year-old Markey, who has held his Senate seat since 2013 following a long career in the House of Representatives, represents the more progressive wing of the Democratic Party. His challenger, 47-year-old Congressman Moulton, is positioning himself as a more centrist alternative in a contest that highlights the ongoing ideological divisions within the Democratic Party.

Spencer Kimball, executive director of Emerson College Polling, noted clear demographic divides in voter preferences. “Senator Markey leads the Democratic primary by 13 points among registered Democrats, while Rep. Moulton holds a 38% to 32% edge among unenrolled voters,” Kimball said. “Markey leads women 37% to 29%, while men are essentially split, with 38% backing Moulton and 37% Markey.”

Age also appears to be a factor in voter preferences, with Markey holding a modest 7-point advantage (33% to 26%) among voters under 50. Voters over 50 are nearly evenly divided, with 40% supporting Markey and 38% backing Moulton.

The large pool of undecided voters could prove crucial in determining the final outcome. Kimball highlighted that “groups that are more favorable toward Markey, including women and young voters, are also more undecided than their counterparts.” Women are ten percentage points more undecided than men (33% to 23%), while 39% of voters under 50 remain undecided compared to 21% of voters over 50.

Markey has secured endorsements from prominent Massachusetts Democrats, including Senator Elizabeth Warren and Representative Ayanna Pressley, a member of the progressive “Squad” in Congress. His progressive credentials have helped solidify his standing with the Democratic base.

Moulton, meanwhile, has garnered support from organizations like VoteVets PAC and the Massachusetts Teamsters, reflecting his more moderate positioning within the party. A former Marine who served four tours in Iraq, Moulton briefly ran for the Democratic presidential nomination in 2019 before dropping out.

The poll, conducted on May 3 and 4 with 451 likely Democratic primary voters, carries a 4.5% margin of error, meaning the race is statistically very close. It also measured favorability ratings, finding that both candidates have lower favorable ratings than Senator Warren, with Markey matching Warren’s unfavorable rating of 35%, while Moulton’s unfavorable rating was lower at 26%.

The Massachusetts primary is scheduled for September 1, giving both campaigns several months to make their case to voters, particularly the significant bloc of undecideds who will likely determine the outcome.

This contest represents a major test for Markey, who previously fended off a high-profile primary challenge from Joe Kennedy III in 2020. For Moulton, unseating a well-established incumbent would be a major political achievement and significantly raise his national profile.