Why Pennsylvania election results may be slow on election night

Like a horror movie villain, the “red mirage” is back with a sequel.

Four years ago, Donald Trump used the fact that Republican ballots cast in person on Election Day were counted faster than Democratic mail-in ballots to prematurely declare victory, setting off a series of events that led to the deadly attack on the U.S. Capitol led.

In the key state of Pennsylvania, that underlying dynamic – which caused the “red mirage” of a Trump victory on election night to lead to a “blue shift” in the counting of Democratic votes – is still present.

Because of opposition from Republican lawmakers, Pennsylvania has not updated its laws to allow for faster counting of mail-in ballots. With Trump and Kamala Harris tied in the polls in the battleground state, that means it could be a while before the winner is known, adding to the uncertainty. A number of election models suggest that Pennsylvania is the state most likely to decide the presidential election.

From a legal perspective there is nothing wrong with this. A ballot counted right after the polls close is worth the same as a ballot counted the next morning, and election administrators would rather get the vote totals right than get them faster.

But the delay could give Trump a chance to argue to his supporters that the election is being stolen, as he did in 2020.

Pennsylvania prohibits officials from opening and processing mail-in ballots before Election Day. In other states, the laborious process of verifying signatures, removing ballots from envelopes and stacking them for counting can begin in the days beforehand, allowing votes to be counted almost as quickly or even faster than ballots cast on Election Day himself.

In the past, this wasn't a big problem because voters from both parties were equally likely – or unlikely – to vote by mail.

But Trump's attacks on mail-in voting in 2020 had a lasting impact, causing Democrats to vote by mail at a much higher rate than Republicans. The GOP has made great efforts to persuade its voters to “overwhelm the vote” by casting a vote earlier this year, with at times support from Trump, but that appears to have produced mixed results so far.

Data from the University of Florida Election Lab's Early Voting Tracker for the 25 states that report early voter party registration showed that as of the end of last week, about 39% of the total vote came from Democrats, 36% from Republicans and 25% from independents and third parties . Additionally, results from the six states that also report early voters by gender – Colorado, Georgia, Idaho, Michigan, North Carolina and Virginia – showed that about 54% of votes came from women, 44% from men and 2% from unknown voters.

Given the gender gap in Harris' favor, that could mean early voting is even more in her favor.

The “red mirage” phenomenon was detailed in a 2020 study by data firm Hawkfish, which is funded by former New York Mayor Michael Bloomberg and has worked for the Democratic National Committee.

Trump, who has claimed that his losses in everything from the Emmys to the 2016 Iowa caucuses to the national popular vote were solely due to fraud, has again made baseless claims about the 2024 election. He recently posted on Truth Social that there was “(really) bad election 'stuff' going on” in Pennsylvania and claimed without evidence that there was “rampant fraud and fraud” in the 2020 election.

Harris told NBC News that her campaign was prepared for the possibility that Trump could prematurely declare victory.

“We will deal with election night and the days after as they come, and we have the resources, expertise and focus here too,” she said.