I think I've finally figure out the solution to this:

Make a special stamp for universal mail-in voting. It's free. You have to pick it up at the post office, and they collect your name and address, just like you do at the ballot box. That's when you get your ballot, too. Then you have a record of who got their stamp, and all ballots need to be checked against who registered. You will notice if anything shady goes on that way.

Also, since it's Trump, it'd be hilarious if he used his face on the stamp.

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