[peterhunt]

Just do it in person. The voter fills out the ballot in front of the buyer, seals and signs the envelope, and hands it to the buyer in exchange for cash. The buyer then puts it in the mail on the voter’s behalf.

The voter could go to a polling place afterwards and attempt to cast a provisional ballot but my understanding is that this is difficult, varies significantly state to state, and in many cases is not possible given that mail in ballots are detached from the voter identity ahead of Election Day in many states.