Mehmet Oz is leading McCormick by about 1,100 votes as of Saturday afternoon, or 0.1 percentage points. The primary is expected to go to a recount, which will be triggered if the top two candidates are separated by half of a percentage point or less, unless the runner-up waves it off.

Election officials have said they should have a good idea by Tuesday if there will be a recount, and the state’s chief election official must formally make that decision by Thursday.

As outstanding mail-in and absentee ballots have been tallied, McCormick, who is outperforming Oz in such ballots, has gained some ground. On Friday morning, the Department of State said that there were approximately 8,300 Republican mail-in and absentee ballots left to count. That number does not include any un-dated ballots.

There is still uncertainty in the state over how far the circuit court’s decision will extend beyond the 2021 judgeship election. The three-judge panel has yet to issue its formal opinion on the matter — which would more thoroughly lay out both the court’s legal justifications and ramifications of their judgment — nor has the Pennsylvania Department of State issued formal guidance to county election officials. That guidance could come as soon as early next week.

Casey Contres, the campaign manager for Oz, said in a statement that “the McCormick legal team is following the Democrats’ playbook” and it “will oppose the McCormick legal team’s request that election boards ignore both Pennsylvania’s Supreme Court and state election law and accept legally rejected ballots.”

The 3rd Circuit Court of Appeals found its judgment Friday that the state’s law requiring that ballots be dated by the voter is “immaterial” under the federal law — meaning they should have no bearing on whether ballots are accepted or rejected.

Federal statute that originated in the Civil Rights Act of 1964 reads that no person should be denied the right to vote in an election “because of an error or omission on any record or paper relating to any application, registration, or other act requisite to voting, if such error or omission is not material in determining whether such individual is qualified under State law to vote in such election.”

A battle between the Republican Senate candidates over mail-in ballots — already a controversial voting method among much of the GOP grassroots after former President Donald Trump focused much of his post-election conspiracy theories on them — threatens to divide the party ahead of November’s hotly contested election.

The state Supreme Court ruled shortly after the 2020 general election that ballots that were missing dates should be counted. But crucially, the fourth and deciding vote for that outcome wrote that in future elections, un-dated ballots could be disqualified for that reason, since voters would have ample notice about the requirement.

But election officials in the state, for example, already accept ballots where voters write an incorrect date on them, such as their date of birth or a date in the future, according to election attorneys in the state.

Even after the 2020 state Supreme Court ruling, there have been arguments over undated ballots in the state. Republican lawmakers threatened in 2021 to impeach Philadelphia election officials if they counted mail-in ballots that lacked dates.

The federal court’s decision would also not affect ballots that arrived after the return-by deadline, which was close of polls on Tuesday. Those ballots would remain uncounted.

A spokesperson for the Department of State on Friday said it was not immediately clear how many undated ballots had been received on time in this year’s primary.

In one example, a Philadelphia election official said there were about 100 Republican ballots that lacked dates, though that number was expected to go up slightly because the city had not yet processed all mail-in and absentee ballots.

Ronald Hicks Jr., an attorney for the McCormick campaign, said in its letter that “[w]e trust that in light of the Third Circuit’s judgment you will advise your respective Boards to count any and all absentee or mail-in ballots that were timely received but were set aside/not counted simply because those ballots lacked a voter-provided date” and to “the extent you are not willing to provide this advice, we ask for a formal hearing before your Boards on this issue.”

Contres said “David McCormick has been a formidable opponent, but it is becoming obvious that he is likely going to come up short to Dr. Mehmet Oz” and that his legal strategy “could have long-term harmful consequences for elections in the Commonwealth of Pennsylvania.”

Ellen Lyon, the Department of State spokesperson, said it would issue guidance to counties on the impact of the federal court order on Tuesday’s election. She said the agency was “pleased” with the court’s interpretation, signaling that it would likely tell counties to tally the undated ballots.