Election officials in Lancaster County, Pennsylvania, just announced that the company that printed its mail ballots included the wrong ID code, which will delay counting at least 21,000 ballots. Those votes will now have to be hand-marked on new ballots, which could take several days.
Now, these are just some of the ballots in just one county, so we will probably still learn who won Pennsylvania’s primaries tonight. That said, if one of the races is super close, we may need to wait for these ballots to be counted before we can declare a winner.