The New York Times had a very interesting analysis of the effects of Comey’s “October Surprise” on the elections. The takeaway is that if you look at when the poll was taken, rather than when it was released, there appears to be little if any effect:
On Friday, Oct. 28, James B. Comey, the F.B.I. director, sent a letter to Congress about new evidence in the investigation into Hillary Clinton’s emails. Politicians, analysts and journalists are still debating whether the letter cost Mrs. Clinton the presidency. It’s certainly possible. But I am not at all sure, in part because of the final Upshot/Siena College poll in Florida.
I had learned the results of our survey that morning. It showed Donald J. Trump ahead of Hillary Clinton in the state by four percentage points, 46 percent to 42 percent.
But it’s now clear that Mrs. Clinton was weaker heading into Oct. 28 than was understood at the time. Several other polls were conducted over the same period that showed Mr. Trump gaining quickly on Mrs. Clinton in the days ahead of the Comey letter. And the timing of these polls — particularly the gap between when they were taken and when they were released — has probably helped to exaggerate the effect of Mr. Comey’s letter on the presidential race.
But the Upshot/Siena poll of Florida is one of several surveys that challenge this interpretation. That poll was completed the night before the Comey letter, but it was not released until Sunday, two days later — a longer lag than usual, since Sunday is seen as a better day for news media coverage than Saturday.
Some analysts have used poll aggregators or forecasting models to measure the effect of the Comey letter, and they have implicitly treated this Upshot poll, and others conducted before the news but released after, as evidence of a Comey effect. But it can’t be; for example, none of the people we polled for our survey knew about the letter.
In retrospect, there is virtually no evidence to support the view that Mrs. Clinton really had a six-point lead by Oct. 28, even if it was a very reasonable interpretation of the polls that had been released to that point. She didn’t have a six-point lead in any of the 16 (sometimes low-quality) national surveys that went into the field on or after Oct. 23 and were completed before the Comey letter, including her steadily shrinking lead in the ABC/Washington Post tracker.
A new report from the American Association of Public Opinion Research on 2016 polling reached a similar conclusion.
Of course, I don’t expect this to change the narrative being being promulgated by the Democratic Party establishment and the Clinton camp.
As Upton Sinclair once said, “It is difficult to get a man to understand something, when his salary depends on his not understanding it.”