MassINC poll puts Markey up 26; our Massachusetts forecast barely moves

A MassINC Polling Group survey for Commonwealth Beacon, fielded September 14-22 among 800 likely voters, finds Democratic Sen. Ed Markey at 54 percent and Republican John Deaton at 28 percent. That is a 26-point gap. Independent candidates drew 3 percent and other candidates 2 percent.

The poll confirmed what our forecast already showed. Our model still gives Markey a 100 in 100 chance of winning the seat. That figure is rounded, and it is not a certainty. Our projected margin moved from D+37.9 in the previous run to D+38.0. The range between our 5th and 95th percentile outcomes is unchanged, at D+21.5 to D+54.4.

The MassINC result is well inside that range but below our central estimate. A 26-point lead is still a wide one. Because it sits near the lower end of our range, the poll did not pull our average margin down in any meaningful way. The new run left the race where it was.

Nationally, our model gives Democrats a 59% chance of winning Senate control and Republicans a 40% chance. Democrats need 51 seats for a majority. Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to them. Our model's average outcome is 51.0 Democratic seats, so the chamber is close in our simulations. Massachusetts is not one of the seats driving that uncertainty.