Pennsylvania's GOP US Senate primary remains deadlocked

The Republican U.S. Senate primary remains up for grabs, turning Pennsylvania's Election Day into election week.

State of play: Celebrity doctor Mehmet Oz, backed by former President Trump, and former hedge fund CEO Dave McCormick remain deadlocked in the contest.

• Oz is ahead by fewer than 1,300 votes out of more than 1.3 million counted, as of Thursday.

By the numbers: Approximately 51,000 mail-in and absentee ballots remain to be counted as of Thursday morning, according to Mark Walters, a spokesperson for the Pennsylvania Department of State.

• Of those, an estimated 17,000 were cast by Republicans.

Between the lines: On Thursday, Lancaster County had remarked and scanned approximately 16,000 mail-in ballots that had printing errors, said Ray D'Agostino, chairman of the county's Board of Commissioners.

What they're saying: Pennsylvania is expected to count all ballots "within a few days," Department of State spokesperson Grace Griffaton said.

• "We might know sooner than that, but given the possibility of recounts and the need for official certifications, among other potential issues, it is not reasonable to expect final results in all races on primary election night — or even the next day," she said.

Meanwhile, Trump has called on Oz to declare victory, Politico reports.

• "It makes it much harder for them to cheat with the ballots that they 'just happened to find,'" Trump said on his social media platform, Truth Social.

Zoom out: A recount is triggered in Pennsylvania when the margin of victory is within 0.5%, per state law.

What's next: Counties will begin adjudicating ballots today, which involves giving certain ballots additional scrutiny to determine whether they should be counted.

• Counties face a 5pm Tuesday deadline to report unofficial results for statewide offices.