Mail-in ballots I’ve seen are in a security envelope and you can’t see the party affiliation.
If you hand-deliver a ballot to the post office, the mail carrier is out of the loop.
The potential for fraud is after the election when there will be all those suddenly-discovered democrat mail-in ballots in the trunks of election workers cars and closets.
Easier said than done these days. If a person doesn't drive in my area getting to the post office is almost impossible.
:: If you hand-deliver a ballot to the post office, the mail carrier is out of the loop. ::
If the ballot is identified as a mail-in ballot and the instructions tell you to mail the ballot, you will run the risk of having it invalidated because it has no post mark.