I'm an IT professional, specializing in system and network security. While I have to admit that constructing a perfectly accurate and 100% tamper-proof e-voting system is hypothetically possible (though highly unlikely), this whole argument misses the point.
The absolute number one requirement for any voting system is that the entire process must be transparent to virtually every citizen. It is this transparency that ensures fairness, accuracy and security. Since, with any e-voting system, the entire recording/counting process is conducted by program code that only a miniscule percentage of US citizens can understand, e-voting systems are inherently NOT transparent.
I'll repeat that, in case you missed it: E-voting systems are inherently NOT TRANSPARENT!!
You might suggest that those of us who CAN read code can attest to a system's accuracy and security, but what if other experts disagree? How is it decided which experts are correct, are telling the truth? Who does this deciding? Someone who can read code? How does one who cannot read code trust THEIR decision? How does one trust the count?
Open Source doesn't address the transparency issue except among people who can already read code. That still leaves the process opaque to the other 98% of citizens/voters.
The "paper trail" solution is also specious. I personally deal with, on average, five malware-infected PCs a week that are doing one thing while displaying or printing something completely different. So, a voter votes and the machine prints a receipt that verifies his input, but the system still records his vote as something else. Yes, you can hand-count all the receipts in full public view as the official vote count, but then you've simply had the voter use a really fucking expensive pencil to mark his ballot.
And, of course, all of this ignores a prime IT directive: "If it ain't broke, don't fix it."
So, what precisely is "broken" with a voting system that uses paper ballots, hand-marked and hand-counted in full public view?
If you want to take action to ensure that future elections produce a fair and accurate count, you can start by clamoring for your local election officials to reject ALL e-voting systems in favor of paper ballots, hand-marked in private and then hand-counted in full public view.