New Hampshire poll puts Pappas up 12, and our forecast barely moves

A Saint Anselm College survey of 1,411 likely voters, fielded August 17-18, put Democrat Chris Pappas at 49% and Republican Scott Brown at 37% in the race for New Hampshire's open Senate seat.

The number confirmed rather than changed our read. Our model now gives Pappas a 95 in 100 chance of winning the seat, up from 94% in the run at 6:30 PM ET on August 20. Our mean margin moved to D+11.2 from D+10.3. The wider distribution shifted slightly with it: our 5th-to-95th percentile range now runs from D+0.2 to D+22.3, where before it extended to R+0.5. That means close outcomes remain inside the range we consider plausible, but our simulations no longer produce a Republican win at the 5th percentile.

The seat is open. Democrat Jeanne Shaheen is the incumbent and is not on the ballot in our race file; Pappas and Brown are the listed candidates.

The national picture is less settled than this race. Our average of 25 generic-ballot polls over the past 45 days stands at D+6.7. In the Senate, our model gives Democrats a 48% chance of winning control against 52% for Republicans, with a mean of 50.2 Democratic seats. Democrats need 51 seats for control and Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to the Republicans. In the House, our model gives Democrats a 94% chance of a majority, with a mean of 242.3 seats against the 218 needed. That House figure carries a caveat of our own making: our simulation correlates error nationally, by census division, by state and by district, but we have no data to correlate demographically similar districts wherever they sit, so the control probability is marginally firmer than a fuller error model would leave it.