I have been involved in mail-in voting and counting votes as that's the way labor unions vote for their office holders.
The envelope-in-envelope method does in fact result in a totally secret ballot.
My question is, are people so ashamed of their votes that they want them kept a secret?
I've voted in every general election since 1968, and it would have been before that had there been the 18-year-old vote at the time.
Every single time, I voted a straight Democratic ballot from top to bottom.
I've never cast a vote for a Republican in more than a half-century of voting.
See? Those were secret ballots that didn't need to be secret.
Post them in the newspaper for all I care.
I've never been ashamed of my vote or too scared for it to be public.