Nebraska poll shows Ricketts and Osborn tied; our model still favors Ricketts

An Impact Research survey of 600 likely voters in Nebraska, fielded August 9-13, put Republican Sen. Pete Ricketts and independent Dan Osborn level at 47 percent each.

Our model moved, but not far. The new run gives Ricketts a 98 percent chance of winning the seat, down from 99 percent in the previous run at 8:30 AM ET on August 26. Osborn and any other non-major-party candidate get 2 percent, up from 1 percent. The Democratic chance in this race remains 0 in 100; no Democrat is in our candidate list here. The expected margin narrowed to R+13.4 from R+16.2, and our 5th-to-95th percentile range now runs from R+23.9 to R+2.6, against R+26.9 to R+5.3 before.

That gap between a tied poll and a double-digit expected margin is the model declining to take one survey at face value in a state where its priors are strong. The poll pulled the distribution toward Osborn at both ends without changing which side of the race the model expects to be ahead.

Nationally, our Senate numbers are unchanged in character: a 44 percent chance Democrats win control against 56 percent for Republicans, with a mean of 49.9 Democratic seats. Democrats need 51 seats for control; Republicans need 50, because the vice president is a Republican and a 50-50 tie goes to them. In the House, our model gives Democrats a 93 in 100 chance of a majority, with a mean of 240.9 seats against the 218 needed. Our generic-ballot average stands at D+6.5 across 27 polls in the last 45 days.

One caveat on the House figure: our simulation correlates error nationally, by census division, by state and by district, but it has no term linking demographically similar districts in different places. We lack the cluster data to build one, so that 93 percent is marginally firmer than a fuller model would report.