Blockchain would definitely solve this: Traceability, verifiability (no double casting). If you dont trust the counters (which no1 in america should) you can also use a form of Secure Multiparty Computation to hide the outcome from the counters until the last ballot is cast. So ya.

> you can also use a form of Secure Multiparty Computation to hide the outcome from the counters until the last ballot is cast

That sounds like a terrible idea. What happens when somebody tries to hold the election process hostage by not casting a vote?

That will never happen because voting happens during a finite window of time.