From Nate Silver’s write up on this poll:

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.

Emphasis mine. While polls were decently off in 2016 and 2020, Selzer’s were not, and reflected a significant underestimate of Trump by nearly every other pollster. This poll suggests Harris is being underestimated. If Selzer is correct, Harris wins very comfortably.

It’s hard to explain how unexpected this result is. Harris proponents like myself were hoping for Trump +8-9 or less, which would correlate to a Harris win in the electoral college. You can still see this on r/fivethirtyeight from the bad site. I’m not optimistic and my best hope was Trump +7. People misread this as Trump +3 and were still celebrating. Headlines aren’t exaggerating here: this is a truly shocking poll. If the real result is even Trump +5, he is likely to have lost handily. If this is as accurate as Selzer has been since 2012, he will have lost in a true landslide. (Let’s not get ahead of ourselves, of course.)

I’ll link again Silver’s article on herding because it makes a strong case that most polls are not currently reliable due to self-preservation. Selzer releasing these results is not a self preserving move and would be a large pockmark on her otherwise “near-oracular” record.

You can scroll through my history and see that I am not an optimistic person. I initially assumed a Harris loss before Biden dropped out because RFK was still polling too well, a traditional indicator of loss when dropping incumbent status. I was pleased with her upward momentum— and still am, she deserves a great deal of credit for an excellent campaign— but she has always been the underdog in my mind. This is the most positive sign I’ve seen all season. It helps that Siena’s most recent PA poll was also quite positive at Harris +4 if I recall.

I’m too worried to be hopeful, but this has made it harder to doom. It’s so unexpected that I take it with a grain of salt, but if she’s even half right, things are a lot better than they feel.

She’s like the Allan lichtman of polling! (Really accurate even when other pollsters are all saying the same by wrong thing together)

She’s been the most accurate Iowa pollster for over two decades now. She doesn’t venture out of Iowa. However, that allows her to laser focus in on the voters there.