Our Iowa Senate estimate moves 31 points back toward Hinson

Our model now gives Josh Turek, the Democrat, a 35 in 100 chance of winning Iowa's open Senate seat, down from 66% in our August 30 run. That is a shift of 31 points toward the Republican, Ashley Hinson, over seven days.

The mean margin moved with it. Our August 30 run had the race at D+2.6 on average; this one has it at R+2.5, with a 5th-to-95th percentile range of R+12.7 to D+7.8. The earlier run's range ran from R+8.0 to D+13.3. Both spans are wide enough to include comfortable wins for either candidate.

One poll of the race was completed in the interval. Emerson College, sponsored by Nexstar, surveyed 750 likely voters from August 31 to September 1 and had Hinson at 49.5% and Turek at 45.1%, with 0.8% for others. The payload gives no margin of error for that survey, so we describe the race as close rather than the gap as a lead. The two surveys that preceded our August 30 run — an Abacus Data poll of 323 likely voters fielded August 26-28, with Turek at 48% and Hinson at 41%, and a Wedgewood Polls survey of 600 likely voters fielded August 27-29, with Hinson at 50% and Turek at 48% — are already inside both estimates.

We published a 59-41 estimate favoring Hinson on August 31, so most of this week's movement was in place before the Emerson field dates closed. The rest of the change is the model's own reweighting, and the payload does not isolate a further cause.

Nationally, our model gives Democrats a 43% chance of winning Senate control, with a mean of 49.9 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.