Vice President Harris’s less-than-stellar early and mail vote turnout in the pivotal swing state of Pennsylvania will force her to have a strong election day turnout in order to carry the state, according to numbers that were reported on Monday. Democrats’ strong early and mail vote advantage in 2020 helped deliver President Biden the White House. 

According to data released by the University of Florida’s Election Lab on Monday, Democrats have returned just 83 percent of their mail ballots, while Republicans have returned 82 percent. More than 1.7 million ballots have been cast so far, with Democrats handing in just under one million and Republicans returning nearly 600,000, giving Ms. Harris a cushion of just over 400,000. 

In 2020, when mail and early voting was far more prevalent due to the pandemic, the Democratic raw vote advantage and the return rate advantage were much higher. By election day, Democrats had cast 1.9 million mail votes, compared to Republicans who had cast fewer than 800,000. Democrats’ return rate for mail ballots was nearly 88 percent, while the Republican return rate was less than 80 percent. 

On Monday, the Trump campaign released a memo to the press detailing what they called Ms. Harris’s “turnout problem” headed into election day. They pointed out that turnout in urban areas and among women — Ms. Harris’s base — is well below where it was at this point in 2020. More than 450,000 fewer women have voted as of Monday than had voted the day before the 2020 election, and 380,000 fewer urban voters have cast ballots than at this point four years ago. 

“Democrats are spinning themselves and reporters by claiming that their voters will turn out on Election Day when polls show otherwise and, most importantly, that’s asking Democrat voters to do something they have absolutely no history of doing. If Democrats, who historically vote ahead of Election Day, haven’t been motivated to show up for Kamala yet, why do we expect them to show up tomorrow?” the Trump campaign writes in its memo. 

Trump has his problems in the early and mail vote data too, according to the data firm TargetSmart that is tracking the voting data. According to their analysis, women have far outpaced men in early and mail voting, even if overall numbers for women are down. As of Monday, women in Pennsylvania had cast 55.6 percent of early and mail votes, compared to men who had cast just 43.2 percent.