In an interview with the far-right radio host John Fredericks, Mastriano named three counties that were being targeted — Philadelphia, Tioga and York — and said they might do a “round two” of counties. A Philadelphia official confirmed to POLITICO that it had received a letter from Mastriano but declined to comment further.

Mastriano’s office did not immediately respond to a series of questions from POLITICO.

Mastriano’s push is inspired by a similar effort in Arizona, which recently concluded its review of millions of ballots from Maricopa County. The Arizona push, led by the GOP-controlled state Senate, is referred to by proponents as an “audit” — but election professionals and local and state election officials nearly universally deride it as an unprofessional fishing expedition that doesn’t rise to the standards of an actual audit. Mastriano had traveled to Arizona to view that review, praising the effort.

“My goal is to do similar to what we saw in Arizona, in that every ballot is photographed and magnified, and we can determine what ballots were filled in by a human,” Mastriano said in the radio interview.

Trump himself has pushed for a review in Pennsylvania, attacking Republicans who did not back his calls. “Are they stupid, corrupt, or naive? What is going on?” he said in a statement last month. “What went on in Philadelphia and other areas of the State must be properly and legally exposed.”

In his announcement and interview, Mastriano continued to allude to unsubstantiated allegations of fraud in the election, citing changes made to the rules to ease pandemic-era burdens on voters. “It would defy logic to assume that an election with the kinds of drastic changes we saw in 2020 was run perfectly with zero errors or fraud,” he wrote.

Biden carried Pennsylvania by 81,000 votes — more than twice the margin that would have triggered an automatic recount.