So what would this mean if something similar happened on election night in Pennsylvania? Well, if we use what our presidential forecast currently says about the race in Pennsylvania, we can game this out a little to understand what the vote count might look like on Nov. 3. We should be clear, though, that this analysis has its limits. We can’t know for sure how many Pennsylvanians will actually vote in November or the pace and trend of the count. Not to mention, counting the votes in two separate primaries is different from counting the votes in one presidential contest.
Right now, our forecast estimates that about 6.8 million votes will be cast in Pennsylvania, on average, and the average popular vote result gives Biden about a 5-point edge over Trump, 52 percent to 47 percent. If that panned out, that means Biden would win about 3.6 million votes to Trump’s 3.2 million (with a few additional votes for other candidates). And if the vote count followed what we saw in the primary, less than half of Biden’s votes would be in by 3 a.m. on election night, whereas around 70 percent of Trump’s would be reported.
That means we could be looking at a situation where Trump has about a 16-point lead, 58 percent to 42 percent, based on approximately 60 percent of the total expected vote. But over the course of the next few days — again, assuming the same pattern we observed in the primary — Biden would win two-thirds of the remaining votes, which would precipitate a 21-point shift in the overall margin from 3 a.m. on election night to the final result, as the chart below shows.
Now, it’s entirely possible the actual shift isn’t as large as the one outlined above. After the primary, local election officials in Pennsylvania now have some experience in handling a huge number of mail ballots. The state has also made investments to expedite the vote count. Plus, a sizable share of mail ballots will have already been turned in by Election Day, so administrators could have the majority of all mail votes when they begin processing them on Election Day morning. Pennsylvania officials also want to make sure that voters aren’t surprised by a sizable vote shift so plan to be as transparent as possible. Secretary of State Kathy Boockvar has said she will call on county election officials to regularly report the progress in counting mail ballots, instead of reporting them all at once, to avoid a huge swing in the vote that might cause confusion. And she’d also like the state to share how many ballots are left to count, where they are in the counting process and the party affiliation of the voters who cast those remaining votes.
Still, we’re talking about a lot of votes that have to be processed. Just 2.7 million people cast ballots in Pennsylvania’s presidential primary, about 40 percent of the total turnout we’re expecting in the general election. In fact, more people have requested mail ballots than voted in Pennsylvania’s presidential primary, period. That means even if officials are better prepared, they will still have far more mail ballots to process than in June. And while they can begin processing at 7 a.m. on Nov. 3, that still means verifying and processing each ballot, and only then counting each vote. This could take days, which could affect how quickly we know who won the election.