Once a bad registration is in the rolls, it is almost impossible to remove. As an example, to remove a registration for a non-citizen, it is necessary to provide documentary proof that the registration is for a non-citizen. Usually that means that someone has to locate the registered person and have them sign an affidavit that they are not a citizen, and then present that document to the appropriate authority.
This could be difficult if the individual has been deported, or is reluctant to sign a document that would be admission to a felony. Lacking such proof, the registration remains, and in eight states with universal vote by mail, a ballot will be sent to the registration address. No problem there! Of course, no-one would ever mark and return a ballot that didn't belong to them!
I've already written about the dangers of dirty voter rolls here and here, and how they can be used to support election fraud. The Carter-Baker commission in 2005 listed absentee voting (vote by mail) as the greatest threat to election integrity, yet every state has some provision for absentee voting, and eight states, California and Washington included, have universal vote by mail. Have we learned nothing in these last twenty years?
There are those who believe the election officials who claim that our elections are safe and secure and that we have numerous safeguards in place to ensure that no-one can tamper with our results. That and we can always trust the fox to give an accurate report on the health of the henhouse, too.
After all, we have ineffective signature checking to ensure that every mail in ballot is signed by someone—sometimes even by the actual voter. And of course, we use paper ballots to record the votes—never mind that all the counting is done from ballot images that can be altered or duplicated by the millions.