In Many States, The Vote Tonight Might Look Very Different From The Eventual Result
We know that mail ballots are far more likely to be cast by Democrats than Republicans, who are more likely to vote on Election Day. This means that in some states -- though certainly not all -- more Republican-leaning Election Day votes may be counted ahead of many Democratic-leaning mail ballots, and as the latter are reported, they could swing the vote toward Biden, creating what’s known as a “blue shift.”
Take Pennsylvania, where election officials couldn’t begin processing mail ballots until 7 a.m. today. As a result, Trump could very well lead there tonight but lose that edge as the count proceeds. To get some idea about what such a shift might look like, I analyzed Pennsylvania’s June 2 presidential primary, which saw a huge surge in mail balloting that slowed counting. By 3 a.m. on election night (June 3), only 46 percent of the final Democratic vote had been reported, compared to 71 percent of the GOP total, based on data from ABC News.
If we apply the pattern of returns from the primary to data from FiveThirtyEight’s forecast, we can get an idea of what a blue shift could look like. On Oct. 28 -- that’s when I originally did this analysis, but not much has changed -- our forecast estimated 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, Biden would win about 3.6 million votes to Trump’s 3.2 million (with a few additional votes for other candidates). But if the count were to mimic the primary’s trend, Trump would have about a 16-point lead at 3 a.m., 58 percent to 42 percent, based on approximately 60 percent of the total expected vote. But over the course of the next few days, Biden would win two-thirds of the remaining votes, which would precipitate a 21-point shift in the overall margin, as the chart below shows.
Now, this analysis has its limits, as it’s impossible to say just how the count will go and how much the vote may shift in Pennsylvania. However, the primary results there suggest that we should be ready for a sizable swing.
And one fear about a blue shift is that Trump could try to declare victory based on initial returns, as he’s claimed the result should be known on election night. A premature declaration of victory by Trump would have no legal bearing, but he could then point to the shift as evidence of fraud to cast doubt on Pennsylvania’s vote, as he’s made false claims about voter fraud numerous times already. But in reality, such a swing would simply be due to a prolonged count brought on by the increase in mail voting -- nothing sinister at all. So we shouldn’t be surprised if Trump leads tonight but loses Pennsylvania once a lengthy count is completed after tonight.