But yes a distributed e-voting system based on blockchain or whatever could work and maybe much cheaper as it would only take a few minutes online to vote. The result could be that more referendums would be held more often.
In other words, it's not the backend that's the worry so much as the frontend. (Leaving aside all the blockchain-specific issues)
Block chains record votes cast in order. Which correlate with the order those same ballots were issued (or received, as with postal ballots). Voila, no more secret ballot.
The proposal to fudge the time stamps (chunking, roundoff or jitter) does not work for real world USA elections. Because the smallest administrative unit is the precinct (from 0 to 1000 voters) and ballot casting is bursty (vs spread evenly over time).