Older Massachusetts polls widen our Markey margin to D+35.6

Our model now puts the Massachusetts Senate race at a mean margin of D+35.6, with a 5th-to-95th percentile range of D+17.1 to D+54.0. The run before it, at 4:03 PM ET on Sunday, had the mean at D+28.9 in a narrower band of D+18.1 to D+39.6. The probability did not move: Ed Markey's chance of winning is 100 in 100 in both runs, as it was before the latest polling arrived.

What changed is the polling record behind the average, not the state of the race. A University of New Hampshire survey of 600 likely voters, fielded April 16-20, had an unnamed Democrat at 56 percent and Republican John Deaton at 25. A companion UNH survey of 603 likely voters over the same dates had Markey at 55 and Deaton at 32. A Suffolk University poll for the Boston Globe, 500 registered voters fielded November 19-23, 2025, had a generic Democrat at 52 and Deaton at 29. The oldest entry, a YouGov poll for UMass Amherst and WCVB-TV of 700 adults fielded February 14-20, 2025, had Markey at 35 and a generic Republican at 33 — a close result, and the only one in the file that is.

The most recent survey remains UNH's 906 likely voters for 7News, fielded August 20-24, with Markey at 49, Deaton at 30 and 7 percent for others. Our mean margin now sits above the margin in any single poll in the file, including that one.

Massachusetts is not where the Senate is decided. Nationally our model has Democrats averaging 50.2 seats against the 51 they need for a majority, with Republicans needing 50 because the vice president is a Republican and a 50-50 tie goes to them. It gives Democrats a 49 percent chance of Senate control and Republicans 50 percent.