Having witnessed the use of provisional ballots first-hand during the March primary election, I agree with the main thrust of this AP report
, that problems could be caused if vote margins are close and a large number of provisional ballots are issued, now that their use is mandated across the country. In principle, they are a good thing, allowing people to vote despite bookkeeping foul-ups or other voter roll nonsense. In practice, they introduce a level of complexity and uncertainty into a process that is otherwise fairly unambiguous: you come in, you produce i.d. or a registration card, you either are or are not on the rolls, and you vote or you don't vote. Of course there are contigencies at each step, but what's nice about this process is that there's a fairly straightforward decision tree for election judges and poll watchers. Since the issuance of a provisional ballot is sort of a catch-all for election day, the potential for making mistakes or mischief is higher. As a coordinator of several precincts' worth of poll watching during the primary election, we were at times in different polling places when voters were issued provisional ballots and shouldn't have been (they didn't have an affidavit or person vouching for their identity) and times when they weren't issued provisional ballots and should have been (the election judge didn't understand the guidelines, or gave the voter a regular ballot). I don't believe any malfeasance was taking place here - really, it was more that the judges were out of their depth and not properly trained - but as the article says, the process didn't result in many actual votes.
In software development - and I'm sure in other fields like engineering - we talk a lot about the "80/20 rule," which means the first 80% of a given project can be finished in 20% of the total time allotted, and then the final 20% of the project takes the remaining 80% of the time. The reason is that it's easy to rough in the structure of a system; it's much harder to deal with all the edge-cases and finely-resolved detail. Provisional balloting as currently implemented feels a bit like the first 80%.