Earlier quoted context omitted.
Not really. Whilst paper voting fraud is definitely possible - maybe even easier than online fraud - in an election, paper ballots are distributed across an entire country. They require "hacking" 1000's of people in order to corrupt a national vote. Computer hacking just requires breaking the security of one application.
You can't bribe open source. I find it hard to believe that a modern identity infrastructure (which we don't have, admittedly) combined with basic cryptography can't get us where we need to be. We might not be able to cryptographically prove anonymity, but all it takes is trusting the government to anonymize the data correctly and make it secure in transport.
Have you read "Reflections on Trusting Trust"?