Pennsylvania

If you arrive at your regular precinct or neighborhood polling place on Election Day, and if something goes wrong, you can still vote on what's called the "provisional ballot." That's what this is about ... so that nobody is sent away from their poll without voting.

It's a good thing that Pennsylvania is careful to make it possible for everyone to vote, as long as we can show a photo ID and prove our permanent mailing address. It won't matter if your name was dropped (accidentally or on purpose), you can use the provisional ballot and vote anyway.

BUT a lot of the controversy in Pennsylvania isn't over the provisional ballots. The controversy is over the much larger number of mailed ballots, because some are being disqualified or otherwise refused in red counties for stupid reasons.
#1 The voter forgot to sign the outside envelope
#2 The voter signed it, but it doesn't look like the signature on file
#3 Well OK, they signed it, but they forgot to DATE it
#4 They dated it but it's the WRONG DATE. (Maybe they wrote their birth date, or something else.)
#5 Well OK they signed and dated the outside envelope, but they forgot to put it in the SECRECY envelope.

In certain blue counties (like Allegheny and Philadelphia) the voter is given an opportunity to correct these mistakes before Election Day, and that's called "ballot curing." In most of the red counties there is no "ballot curing" allowed, and therefore none of those mailed ballots with mistakes will ever be counted. Is it fair? No, but the Repukes don't care because they believe they are disqualifying the ballots of Democratic voters.

This is most definitely a Party issue. Democratic voters are being disenfranchised, and many of them don't realize that it's happening.