The Comey Letter Probably Cost Clinton The Election

I'm putting this in my blog because I still see comments on Facebook denying the facts.

https://fivethirtyeight.com/features/the-comey-letter-probably-cost-clinton-the-election/


The Comey Letter Probably Cost Clinton The Election
So why won’t the media admit as much?
By Nate Silver
Published May 3, 2017

Hillary Clinton would probably be president if FBI Director James Comey had not sent a letter to Congress on Oct. 28. The letter, which said the FBI had “learned of the existence of emails that appear to be pertinent to the investigation” into the private email server that Clinton used as secretary of state, upended the news cycle and soon halved Clinton’s lead in the polls, imperiling her position in the Electoral College.

The letter isn’t the only reason that Clinton lost. It does not excuse every decision the Clinton campaign made. Other factors may have played a larger role in her defeat, and it’s up to Democrats to examine those as they choose their strategy for 2018 and 2020.

But the effect of those factors — say, Clinton’s decision to give paid speeches to investment banks, or her messaging on pocket-book issues, or the role that her gender played in the campaign — is hard to measure. The impact of Comey’s letter is comparatively easy to quantify, by contrast. At a maximum, it might have shifted the race by 3 or 4 percentage points toward Donald Trump, swinging Michigan, Pennsylvania, Wisconsin and Florida to him, perhaps along with North Carolina and Arizona. At a minimum, its impact might have been only a percentage point or so. Still, because Clinton lost Michigan, Pennsylvania and Wisconsin by less than 1 point, the letter was probably enough to change the outcome of the Electoral College.

And yet, from almost the moment that Trump won the White House, many mainstream journalists have been in denial about the impact of Comey’s letter.

•••••

many pundits have preferred to change the conversation when the letter comes up, waving it away instead of debating the merits of the case.

The motivation for this seems fairly clear: If Comey’s letter altered the outcome of the election, the media may have some responsibility for the result. The story dominated news coverage for the better part of a week, drowning out other headlines, whether they were negative for Clinton (such as the news about impending Obamacare premium hikes) or problematic for Trump (such as his alleged ties to Russia). And yet, the story didn’t have a punchline: Two days before the election, Comey disclosed that the emails hadn’t turned up anything new.

One can believe that the Comey letter cost Clinton the election without thinking that the media cost her the election — it was an urgent story that any newsroom had to cover. But if the Comey letter had a decisive effect and the story was mishandled by the press — given a disproportionate amount of attention relative to its substantive importance, often with coverage that jumped to conclusions before the facts of the case were clear — the media needs to grapple with how it approached the story. More sober coverage of the story might have yielded a milder voter reaction.

•••••

Clinton’s standing in the polls fell sharply. She’d led Trump by 5.9 percentage points in FiveThirtyEight’s popular vote projection at 12:01 a.m. on Oct. 28. A week later — after polls had time to fully reflect the letter — her lead had declined to 2.9 percentage points. That is to say, there was a shift of about 3 percentage points against Clinton. And it was an especially pernicious shift for Clinton because (at least according to the FiveThirtyEight model) Clinton was underperforming in swing states as compared to the country overall. In the average swing state,3 Clinton’s lead declined from 4.5 percentage points at the start of Oct. 28 to just 1.7 percentage points on Nov. 4. If the polls were off even slightly, Trump could be headed to the White House.

•••••

Clinton lost Michigan, Pennsylvania and Wisconsin by less than 1 percentage point, and those states were enough to cost her the election. She lost Florida by just slightly more than 1 point. If the Comey letter had a net impact of only a point or so, we’d have been in recount territory in several of these states — but Clinton would probably have come out ahead. I call this the “Little Comey” case — sure, the Comey letter mattered, but only because the election was so close.

•••••

http://election.princeton.edu/2016/12/10/the-comey-effect/

The Comey effect
December 10th, 2016, 10:06pm by Sam Wang

May 9th, 2017: I am re-upping this because of the recent column by Nate Silver on this topic. He had previously addressed the topic of Comey, shortly after the election. I thought he did a good job, both then and now.

I don’t entirely see the need to revisit the topic, which I regard as settled. To me, the other critique in the news illustrates the inadequacy of smoothing methods to forensically extract rapid changes like the Comey effect.

[I have noticed the same thing with the Gallup polls on Trump's approval ratings, which are a three-day running average. Being a mathematician, it is obvious to me that this will hide spikes in approval and disapproval ratings.]

•••••