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.
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.