A new Idaho poll leaves our Risch forecast exactly where it was

A Peak Insights survey of 500 likely voters, fielded September 28-30, puts Republican Sen. Jim Risch at 49 percent. The independent line is at 3 percent and other candidates at 2 percent. The poll does not name the independent candidate. Its published results account for 54 percent of respondents and do not report the remainder.

The poll did not move our forecast. Our model gives Risch a chance that rounds to 100 in 100 of winning the seat. That was also the figure in our previous run, from 6:32 PM ET today. Our average margin is R+28.5, the same as before. The range between our 5th and 95th percentile outcomes runs from R+44.7 to R+12.2. In the prior run it ran from R+44.8 to R+12.2. That is a shift of a tenth of a point at one end.

The absence of movement is the change. Our last several Idaho pieces described a margin that drifted with each new poll while the odds stayed put. This time both the odds and the margin held. Even the closest outcomes in our range leave Risch ahead by double digits.

Nationally, our model gives Democrats a 53% chance of winning Senate control and Republicans 46%. It projects an average of 50.6 Democratic seats. Democrats need 51 for control and Republicans need 50, because a 50-50 tie goes to the Republican vice president.