Ricketts leads by four in new Nebraska poll; our forecast is unchanged

A Wedgewood Polls survey of 500 likely voters in Nebraska, fielded September 14-16, put Republican Sen. Pete Ricketts at 52 percent against a Democratic option at 48 percent. The poll did not report a figure for independent Dan Osborn, who is the other candidate on our list for this race, so the four-point gap it describes is not a test of the matchup our model is simulating.

Our forecast did not move. It gives Ricketts a 93 in 100 chance, with a 7 percent chance for another candidate and a 0 percent chance for a Democrat. The mean margin went from R+15.6 in our previous run, at 12:32 PM ET on September 16, to R+15.5 now. The 5th-to-95th percentile range is R+33.0 to I+2.0, against R+33.0 to I+1.9 before. Those are rounding-scale changes.

That leaves a wide distance between the polling and the model. The Wedgewood result is far tighter than our mean margin, as were the surveys behind our coverage earlier this month. Our model weighs state polling against the rest of what it knows about Nebraska, and at 48 days out it is still discounting single surveys heavily. The practical effect is that this poll confirmed the existing picture rather than changing it.

Nationally, our model gives Democrats a 51 in 100 chance of Senate control, with Republicans at 48 percent. The mean outcome is 50.4 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. Our generic-ballot average stands at D+7.2 across 25 polls over the past 45 days. In the House, we put the Democratic chance of a majority at 96 percent, with a mean of 242.3 seats against the 218 needed.