Maine forecast eases to 84 percent for Jackson after split Abacus polls

Abacus Data released two readings of the Maine Senate race from the same August 26-28 field period, and they do not agree. Among 327 likely voters, Democrat Troy Jackson took 50 percent to Republican Susan Collins's 42 percent. Among 499 registered voters, the two were level at 40 percent each.

Our model now gives Jackson an 84 in 100 chance of winning the seat, with a mean margin of D+6.4 and a 5th-to-95th percentile range running from R+4.2 to D+16.9. That is a step back from the previous run this afternoon, which had Jackson at 92 percent and a mean margin of D+8.8. The tied registered-voter number, and the small likely-voter sample behind the eight-point figure, account for the move. Earlier this month this site published a note putting Jackson at 90 percent; the story since then is a modest narrowing, not a change in who our model favors.

The new polls do not move the race outside the range other recent surveys have described. A Beacon Research/Shaw & Company Research poll for Fox News, of 1,000 registered voters fielded August 6-10, had Jackson at 48 percent and Collins at 46 percent. A University of New Hampshire survey of 1,178 likely voters, fielded July 15-20, had Jackson at 49 percent and Collins at 46 percent. Public Policy Polling, surveying 785 registered voters on July 7, put Jackson at 49 percent and Collins at 44 percent. Several of those gaps are small enough that the race reads as close rather than settled.

Maine matters to the chamber arithmetic. Our model gives Democrats a 49 percent chance of Senate control and Republicans 50 percent, with a mean of 50.2 Democratic seats. Democrats need 51 seats for control; Republicans need 50, because the vice president is a Republican and a 50-50 tie goes their way.