U.S. Senate candidate David McCormick of Pennsylvania sought a court order to allow the Republican to make mass challenges to provisional ballots in Philadelphia in a race he appears to have won, according to court papers.

A provisional ballot is a safeguard ballot that lets voters cast a vote even if there are questions about eligibility.

If the vote in Pennsylvania today is as close as it was in 2016 and 2020, we could be hearing a lot about provisional ballots and "ballot curing" in the days to come. Voters who make mistakes on their mail-in ballots can cast provisional ballots on Election Day in a process known as "ballot curing.