Nate Silver: A shocking Iowa poll means somebody is going to be wrong. Either Ann Selzer and the New York Times, or the rest of the polling industry.

Yesterday, I complained about how so many pollsters are “herding” by publishing results that are almost an exact tie in a way that is incredibly statistically improbable given the unavoidable sampling error from surveying a small number of voters. I also noted a handful of prominent exceptions — rouge pollsters like the New York Times/Siena College that practically exist in an entirely different universe and imply a much bigger political realignment.

Another such maverick is Ann Selzer of Selzer & Co. (Selzer and NYT/Siena are our two highest-rated pollsters.) As my former colleague Clare Malone wrote in 2016, Selzer — like NYT/Siena — has a long history of bucking the conventional wisdom and being right. In a world where most pollsters have a lot of egg on their faces, she has near-oracular status....

So Selzer’s new poll of Iowa tonight was highly anticipated by polling junkies, despite Iowa being unlikely to be a decisive state. In June, Selzer’s poll for the Des Moines Register showed Donald Trump with an 18-point lead over Joe Biden in Iowa — surprisingly big, even considering how much Iowa has trended red over the years. (It voted for Trump by 8 points in 2020.)

In September, her survey had Kamala Harris just 4 points behind Trump — considered an outlier at the time.

Her new poll? It shows the state trending even bluer, with Harris leading in Iowa 47-44.

https://www.natesilver.net/p/a-shocking-iowa-poll-means-somebody