How do they know who the vote is for anyways.
@geronl @Oceander @mystery-akAll mail ballots are mailed in a certain type envelope determined by the state. They are easy to recognize as being mail ballot envelopes. The postal worker would have to open that carrier envelope and would find another sealed envelope actually holding the ballot. That ballot envelope would have to be opened and there is the ballot with the presidential candidate being marked. The postal carrier could throw away the ballot and the two envelopes.
The kicker is, once the envelopes were opened, they couldn't be put together again so they would look unopened. That means all candidate's ballots, both Clinton and Trump, would have to be thrown away as the ballot envelope must be opened to see which candidate was chosen. To make the two sealed envelopes look pristine, like they had not been opened, would require a way to unseal those two envelopes perfectly and put them back together the same way, so they would look new.
If a postal carrier has dumped envelopes, that is election fraud with jail time.