Our Iowa Senate estimate moves 10 points toward Turek in a week

Our model now gives Democrat Josh Turek a 56 in 100 chance of winning Iowa's open Senate seat, up from 45% in our run of September 15. That is a move of 10.4 points of Democratic win probability over seven days. Republican Ashley Hinson is at 44%.

The mean margin moved with it, from R+0.7 in the earlier run to D+0.8 now. Our 5th-to-95th percentile range runs from R+8.8 to D+10.4, so outcomes on both sides of a narrow result remain well inside what the model treats as ordinary.

Three polls carry field dates after our September 15 run. A co/efficient survey of 831 likely voters, fielded September 14-16, had Hinson at 46% and Turek at 42%. Trafalgar Group polled 1,089 likely voters on September 16-18 and had Hinson at 44% and Turek at 42.1%; both of those results describe a close race, and this site has already written about each. The newest is Marist University, which surveyed 1,050 registered voters September 17-20 and put Turek at 50% and Hinson at 42%. That is the only poll in the payload since our last run to show a gap of that size, and it is the clearest available explanation for the direction of the move. An earlier Cygnal Political survey of 500 likely voters, fielded September 9-11 for the Iowans for Tax Relief Foundation, had the two candidates tied at 42.9%.

The seat matters for the chamber arithmetic. Democrats need 51 seats for Senate control, Republicans 50, because the vice president is a Republican and a 50-50 tie goes to the Republicans. Our model gives Democrats a 54% chance of Senate control, with a mean of 50.6 Democratic seats. Iowa is one of the races that decides which side of that line the count falls on.