So what's the threat model here? Is it distrust in the voting machine itself -- because then why do you trust that the paper votes haven't been manipulated by the counters? Are there organizations that would be suddenly able to manipulate votes via electronic machines that are currently unable? Would the same be true if the machines weren't networked and basically dumb counting machines?
It's much harder to manipulate paper votes at scale than voting machines. With paper, people know that the correct vote was recorded (a voting machine could silently change it to something else), and the paper can be protected through a chain of custody with monitors from various groups watching it - and then counted by independent groups.
So the threat model is someone hijacks the firmware in a voting machine to record votes other than what the voter selected, and it's much easier for someone to flip millions of digital bits without being detected than for someone to change the box which is ticked on millions of bits of paper.
The threat model is "any attack that could work will be tried"--elections tend to be about huge power, and there is pretty much nothing some people wouldn't try to obtain that power.
In a properly functioning democracy, any citizen can go and watch the voting process, they can look into the empty ballot box at the start of the day, and watch the people coming to vote all day, to see who gets to vote and how many ballots they get to put into the box, and that voters are effectively being prevented from showing their vote to anyone, and then they can watch the ballot box being emptied and the votes being counted at the end of the day.
Also, in a properly functioning democracy, the voter can rather easily verify that noone is watching them as they vote.
Pretty much none of that is possible with electronic voting.
> Would the same be true if the machines weren't networked and basically dumb counting machines?
1. Yes.
2. How could you verify that there is no network connection anyway?
3. "Network connections" can be accidental. There was the case of the Nedap voting computers in the Netherlands where people from the CCC and Rop Gonggrijp showed that due to non-intentional radio frequency emissions of the machine's circuits, you could find out how people were voting with a short-wave receiver from the other side of the street.
Even without networking, you can usually break anonymity of electronic voting machines through Van Eck phreaking. This probably wont allow you to alter the votes, though.
