New Arizona poll shifts our AZ-2 forecast toward Crane

A Peak Insights survey of 400 likely voters in Arizona's 2nd District, fielded August 17-20, put Republican incumbent Eli Crane at 53 percent and Democrat Jonathan Nez at 42 percent.

That is the only new number in this race, and it moved our forecast. Our model now gives Nez a 42 in 100 chance of winning the seat and Crane a 58 percent chance, with a mean margin of R+2.0. As of our previous run this afternoon, the same model had Nez at 51 percent and the mean margin at D+0.2. The change is almost entirely the arrival of the Peak Insights poll in a race that had little else anchoring it.

The uncertainty around that central estimate is wide and barely narrower than before. Our 5th-to-95th percentile range for the November margin runs from R+18.3 to D+14.5, which covers double-digit outcomes in both directions. A 400-person sample carries substantial sampling error on its own, and one poll two and a half months out does not settle a district our model still treats as close to even money.

Nationally, our numbers have not moved with it. Our generic-ballot average, built from 24 polls over the past 45 days, stands at D+6.6. Our model gives Democrats a 94 percent chance of winning at least the 218 seats needed for a House majority, with a mean of 240.9 seats. One caveat on that figure is ours: the simulation correlates error nationally, by census division, by state and within each district, but we have no data to correlate demographically similar districts wherever they sit. Without that term, the House control probability is marginally firmer than a fuller model would make it. AZ-2, at 42 percent for the Democrat, is one of the districts that would swing either way inside that range.