Mail-in ballots have the same problem of lack of vote secrecy and potential for vote buying that online voting has. The main problems I see with the #ElectionIntegrity process in the US are: mail-in voting (forbidden in most western democracies), tampered/inaccurate voter rolls, opaque electronic counting of the votes, lack of ID verification (in some states). If blockchain-based solution can fix these, that’s great but so far wether US is still a long way to prove that their elections are secured and honest.