Nate Silver said Iowa stood apart as its own group because of the Selzer poll, which he said was not highly accurate.
Unresolvable The public record could not settle it.
Factual: Statements about the present or the past, checked against the record: did they hold up?
What would count as true or false
Judge as of 2024-11-07. Conditions: (a) the final Selzer/Des Moines Register Iowa poll was substantially inaccurate compared with the certified Iowa result; (b) the Selzer poll accounted for most of the gap between the Silver Bulletin model's final Iowa margin and the actual result. Test (b) by the model's documented weighting of Selzer, or by the shift in its Iowa estimate after the poll was released. True: both hold. Mostly true: (a) holds and Selzer accounted for a large but not dominant share of the error. Mixed: Selzer was inaccurate but accounted for only about half of the error, or other polls missed by similar amounts. Mostly false: Selzer was inaccurate but had little effect on the model's Iowa error, which mostly came from other polls or model assumptions. False: Selzer was not substantially inaccurate, or the model had no meaningful Iowa miss.
Set before the research began.
Evidence (12)
-
E1 Seven lessons I didn’t learn from election day ericneyman.blog (Eric Neyman) · 14 November 2024
“But this year, her final poll showed Harris up 3 in Iowa; meanwhile, Trump won by 13 points: a huge miss.”
-
E2 The 2024 Iowa Poll for President: A Cautionary Tale Center for Politics, University of Virginia (Crystal Ball) · 12 December 2024
“In the actual vote, on Nov. 5, Donald Trump carried Iowa by 13 percentage points, for a total forecasting error of 16 points.”
-
E3 The 2024 Iowa Poll for President: A Cautionary Tale Center for Politics, University of Virginia (Crystal Ball) · 12 December 2024
“They concluded “the weighting in this poll was minimal and yielded a final sample of likely voters that matched the percentage of the most recent poll.””
-
E4 How did the polls do in 2024? It’s complicated. Silver Bulletin (Nate Silver) · 17 February 2025 Own record
“Much of this was driven by Selzer’s outlier poll in Iowa that showed Kamala Harris winning the state, but the firm also considerably overestimated Democrats’ performance in House races.”
-
E5 Seven lessons I didn’t learn from election day Eric Neyman (ericneyman.blog) · 14 November 2024
“But this year, her final poll showed Harris up 3 in Iowa; meanwhile, Trump won by 13 points: a huge miss.”
-
E6 Seven lessons I didn’t learn from election day Eric Neyman (ericneyman.blog) · 14 November 2024
“So, what happened? Most likely, the error was a result of non-response bias: more Democrats responded to her poll than Republicans.”
-
E7 Seven lessons I didn’t learn from election day Eric Neyman (ericneyman.blog) · 14 November 2024
“We only saw a large polling bias on Florida and Iowa, neither or which were swing states.”
-
E8 How did the polls do in 2024? It’s complicated. Silver Bulletin (natesilver.net) · 17 February 2025 Own record
“By far the pollster with the largest average error in the 2023-2024 cycle was Selzer, at 12.8 points. Ann Selzer’s firm also had the largest bias — D+14.8 to be precise.”
-
E9 2024 Iowa: Trump vs. Harris | RealClearPolling RealClearPolling
“| Des Moines Register* | 10/28 - 10/31 | 808 LV | 3.4 | 44 | 47 | Harris+3 |”
-
E10 A shocking Iowa poll means somebody is going to be wrong Silver Bulletin (Nate Silver) · 3 November 2024 Own record
“Harris’s chances of winning Iowa nearly doubled in our model from 9 percent to 17 percent tonight, which isn’t nothing.”
-
E11 A shocking Iowa poll means somebody is going to be wrong Silver Bulletin (Nate Silver) · 3 November 2024 Own record
“there was also a second Iowa poll out tonight from Emerson College that showed Trump leading by 9 points, close to the margin from 2020.”
-
E12 Our best and worst takes of 2024 Silver Bulletin (Nate Silver) · 31 December 2024 Own record
“It did conclude the poll (showing Kamala Harris leading in Iowa; she lost by 13 points) would “probably be wrong”. But the poll maybe still got too much weight in my “mental model” of the election. It didn't influence our statistical model much, which took it more in stride as a probable outlier.”
Reasoning
Independent sources support condition (a). Selzer's final Iowa poll showed Harris up 3, while Trump won Iowa by 13, a 16-point error (E1, E2, E9). Condition (b) cannot be tested from this evidence. No item gives the Silver Bulletin model's final Iowa margin, Selzer's weight in the model, or how far its Iowa margin moved. E10 reports only that Harris's chance of winning Iowa rose from 9% to 17%, and Silver's own later review (E12) says the poll "didn't influence our statistical model much." That points against the claim but does not measure the size or source of the model's Iowa error.
Cite this claim
Nate Silver, “Nate Silver said Iowa stood apart as its own group because of the Selzer poll, which he said was not highly accurate.” (said 7 November 2024). Verdict: unresolvable. Reliability API, claim c_eab9c0db3231, method 0.1.0+28da144b, dataset release v1.1.2. https://epistacklabs.com/claims/c_eab9c0db3231
This claim is in dataset release v1.1.2, with the same verdict.
Reply to this claim
More factual claims by Nate Silver
-
Mostly true
“The previous Quinnipiac polls of these states had been quite a bit better for Harris.”
-
Resolved true
“Although John McCain had periods of strong polling in 2008, especially after the Republican Convention, in the end Barack Obama won in a landslide that didn’t justify Democrats’ constant anxieties.”
-
Resolved true
“The recognition that the election is only four weeks away.”
As of early October 2024, the US presidential election is about four weeks away.
-
Resolved true
“And yet, there are dozens of polls released every week.”
-
Mostly true
“This property is even more profound in baseball, where single-run leads are relatively durable because runs tend to come in bunches and the default outcome is not to score at all.”
Verdicts are made automatically; how verdicts are made.