I hate to be "that guy", but this is that rare instance where using a blockchain actually is the right solution to the problem.
Discussion
Not true. Blockchain still doesn't allow you to verify real world identities and prevent double voting or Sybil attacks without a trusted authority.
a vote is better run along nostr rails.
You dont need proof of work to record anything other than money.
A national vote could be delivered with the Badges NIP.