How does the discrepancy between exit polls and results in recent US elections compare to pre-electronic machine margins?

Question

Question

Before we used electronic voting machines, were the discrepancies between exit polls and results in swing states different? I'm simply looking for this information so I can draw my own conclusions as to whether or not I should be concerned about vote manipulation as a US citizen.

While it's true that the data needed to support an answer to this is non trivial, it seems plausible that there may already be peer reviewed paper or reports from credible sources on this that can be cited.

Context

This question has been called a "conspiracy theory" and put on hold as and effort to "promote or discredit a specific political cause, group or politician. It does not appear to be a good-faith effort to learn more about governments, policies and political processes".

There's evidence of states using machines where votes could be changed by bad actors from over 1000 feet away with publicly available hacking software and a $50 antenna:

Schürmann determined immediately that the WinVote had a specific IP address and was able to use a vulnerability from 2003 (CVE-2003-035212) and preinstalled attack payloads in Metasploit (a vulnerability analysis and penetration testing tool) to gain access to the filesystem and escalate privileges to an admin user – meaning he could make the machine think he was an administrator of the system, not simply a mere voter or poll-worker. Once he had this access, Schürmann was able to do anything on the system, from running code, to changing votes in the database, to turning the machine off remotely. This vulnerability had clearly been in the system since 2003, allowing anyone within 150-300 feet of a polling place complete control of any WinVote machine while it was being used. For $50, a hand-held high gain antenna could be purchased that would extend that range to over 1,000 feet and through walls.

And the FBI, NSA, and CIA have all agreed that Russia has been actively working to interfere in US elections. So I don't see how I'm reaching or pushing any kind of agenda here to ask the question I'm asking, which is essentially a less broad form of:

"Has there been any data to support the possibility of vote manipulation since electronic voting has become a thing?"

Which is a fair and reasonable question to ask as a US citizen.

Answer 1

Answer: Exit polls have always been terrible

I'll be pulling extensively from a well sourced article about accuracy over time and highly recommend checking out this high level FAQ on exit poll accuracy.

How accurate were exit polls before electronic voting machines were prevalent?

To answer this, we'll need to define when "electronic voting machines" began being used in wide circulation. Let's first define what an "electronic voting machine" is. I believe what you're looking for is the utilization of Direct Recording Electronic (DRE) machines. Wikipedia defines DRE machines as:

...voting machine records votes by means of a ballot display provided with mechanical or electro-optical components that can be activated by the voter (typically buttons or a touchscreen); that processes data by means of a computer program; and that records voting data and ballot images in memory components.

By that definition, researchers have cited Georgia as the first state to use them in 2002 citing an announcement on their web page "Georgia's Unique Model for Election Reform," www.sos.state.ga.us, Nov. 1, 2002

Accepting election before 2002 as the pre-DRE era and those after as the post-DRE era, we can take a look at how exit poll error compares.

A Washington Post article from 2004 states:

The networks' 1992 national exit poll overstated Democrat Bill Clinton's advantage by 2.5 percentage points, about the same as the Kerry skew

comparing the 2004 error to the 1992 error. Continuing to pull from the article cited at the top about errors over time, it goes on to cite Warren Mitofsky, who ran the 2004 exit poll operation, who wrote in the Spring 2003 issue of Public Opinion Quarterly:

An inspection of within-precinct error in the exit poll for senate and governor races in 1990, 1994 and 1998 shows an understatement of the Democratic candidate for 20 percent of the 180 polls in that time period and an overstatement 38 percent of the time...the most likely source of this error is differential non-response rates for Democrats and Republicans

and continues, highlighting the 2000 exit poll errors

From the internal CNN report on the network's performance on Election Night 2000 (p. 48 of pdf):

Warren Mitofsky and Joe Lenski, heads of the CNN/CBS Decision Team, told us in our January 26 interview with them that in VNS's use of exit polls on Election Day 2000, the exit polls overstated the Gore vote in 22 states and overstated the Bush vote in 9 states. In the other 19 states, the polls matched actual results. There was a similar Democratic candidate overstatement in 1996 and a larger one in 1992

Taking a look at recent accuracy comparisons provided by TDMS Research, historic errors from pre-DRE era exit polling may have actually been worse than post-DRE exit polling, theoretically due to advancements in methodology and the emergence of absentee/early voting data becoming available earlier.