Last week, a flurry of litigation in Pennsylvania clarified the rules for mail balloting there. In short, mail ballots will still be rejected in the key battleground state if voters fail to properly date the affidavits that accompany their ballots — but voters who make any mistake with their mail ballots will be able to vote by provisional ballot instead on Election Day.
The NBC News Decision Desk examined how many mail ballots remain outstanding in the state, as well as how many counties have already identified as deficient. In the event of a close race in Pennsylvania, provisional ballots and their counting will get a lot of attention after Tuesday night.
Voters with outstanding mail ballots will need to ensure that election officials receive them by 8 p.m. Tuesday for them to count. But voters with outstanding or deficient mail ballots can also go to their polling places to vote in person.
The data make it clear that most provisional ballots are likely to come from voters with outstanding mail ballots, rather than voters who’ve already returned deficient mail ballots. And they also make it clear that those provisional ballots may favor Vice President Kamala Harris and the Democratic Party.
The data on mail ballots and potential provisional ballots
Overall, about 2.2 million Pennsylvanians have had approved mail ballot applications, according to public data from the state secretary of state. So far, about 82% have returned their mail ballots, according to the latest figures Monday. That means roughly 390,000 mail ballots are outstanding.
If Pennsylvania’s 2024 election follows the same trend we observed in 2022, that means about 150,000 more mail ballots will arrive in time to be counted, via either the mail or drop boxes. The remaining people with outstanding mail ballots will need to vote in person on Election Day to have their votes count. If these voters show up and surrender their mail ballots, they could vote with regular ballots; if they do not, they’ll vote with provisional ballots, which election officials will count only after they confirm the initial mail ballots were not counted.
In 2022, about a third of voters who requested but did not return their mail ballots ultimately voted in person. Taking 2022 as a guide, we would expect around 90,000 to vote in person, with about 35,000 using provisional ballots.
Given that the outstanding mail ballots are disproportionately held by registered Democrats, we expect those provisional ballots to net Democratic candidates some additional votes that will not be reflected in vote totals until a few days after Election Day.
It is more difficult to estimate how many mail ballots will be rejected once election officials start to canvass them Tuesday. Not only does Pennsylvania reject mail ballots if voters did not sign or correctly date the affidavits on the outside of the return envelopes or enclose the ballots in inner secrecy envelopes, but it also forbids counties from “canvassing,” or opening up, mail ballots before Election Day.
Some counties identify mail ballots with deficient affidavits or missing secrecy envelopes before Election Day without opening them, but some leave the task for Election Day. As a result, in some counties we cannot tell the true status of mail ballots.
Overall, our panel of the available statewide data by day show 5,524 deficient mail ballots as of Monday — 2,258 are missing signatures, 2,471 are missing dates or are misdated, and 795 lack secrecy sleeves. The data also shows that about 4,400 voters have taken advantage of county-specific polices to “cure,” or fix, their problematic mail ballots.
In counties where we expect election officials to have checked mail ballots returned to date for any affidavit or secrecy issues, about 0.8% of mail ballots have ever been recorded as deficient. If that holds true, we’d expect a little fewer than 20,000 deficient mail ballots statewide — but the deficiency rate may be higher in other counties.
Voters who have returned deficient mail ballots and have yet to fix them can vote on Election Day, typically by provisional ballot. Those provisional ballots will be counted, according to the state Supreme Court’s decision last week.
However, at least in 2022, relatively few voters took advantage of that option. Meanwhile, as mentioned above, an estimated 35,000 might cast provisional ballots after having not returned their mail ballots at all.
Looking ahead, we expect there to be a lot of discussion on election night and in the days after about provisional ballots cast by people who had requested mail ballots. There may well be future litigation revisiting, yet again, whether to count provisional ballots cast by people who previously returned deficient mail ballots. But from the perspective of the margin of victory in Pennsylvania, it is important to keep in mind that many more provisional ballots will be cast by people who never return their mail ballots at all.
