Given that we're generally happy to trust online banking, my feeling is that there is a way to make electronic voting secure enough. Where you want to draw that line is subjective though!
I don't think this is the right analogy.
* Citizens constantly monitor their bank accounts
* Citizens are *extremely* upset if an error harms them.
* There are procedures for reversing errors.
* There is a legal system for recourse if errors aren't reversed.
Changing $15,000 back to $18,742 is an easy, painless process. Replacing the ruling party is anything but.
Show me one system -- one computer system ever -- with a proved, actual (not projected) MTBF of 100 years.