"Failing to mark the ballot at all (blank vote), or otherwise defacing the ballot instead of attempting to vote.
Filling out the ballot in a manner that is incompatible with the voting system being used, e.g...:"
Filling a preference ballot out of sequence (also known as donkey vote), eg. 1-2-2-3-4 or 1-2-4-5-6. Many cases, only the 1st 2 choices in these examples would be counted as valid."
-Filling the ballot in a manner that makes the voter's decision unclear.
-Physically deforming ballots, especially those counted by machine."
In Democrats instance, A VOTE BY A DECEASED INDIVIDUAL
If a voter makes a mistake while completing a ballot, it's possible 2 cancel it & [place a new vote]. In the U.S, cancelled physical ballots may be called "spoiled ballots" as distinct from an "invalid vote" which has been cast. lrc.ky.gov/Statutes/statu…
All voters should be aware of the reasons a Spoilt vote happen.
And if you find that your vote is cancelled, You should call your local reps, not a left leaning, Anti Trump reporter.