Having failed to gain traction in their efforts to challenge Pennsylvania’s 2020 election results in court, President Donald Trump and his allies in the state considered an even more audacious proposal to reverse the state’s vote, newly released emails show.

A month after the election, Trump adviser and conservative lawyer John Eastman lobbied Republican state lawmaker Russ Diamond, of Lebanon County — now seeking the GOP nomination for lieutenant governor — with a plan to unilaterally declare a new outcome to Pennsylvania’s popular vote, disregarding tens of thousands of legitimately cast absentee ballots.

Citing baseless concerns over the state’s mail voting procedures, Eastman suggested that GOP legislators could simply make up new vote totals that would declare Trump the victor by applying a mathematical formula — based on absentee ballot rejection rates from prior elections ― to subtract votes from then-candidate Joe Biden.

“Having done that math, you’d be left with a significant Trump lead that would bolster the argument for the Legislature adopting a slate of Trump electors — perfectly within your authority to do anyway, but now bolstered by the untainted popular vote,” Eastman wrote in a Dec. 4, 2020, email to Diamond. “That would help provide some cover.”

That email — among a tranche of Eastman’s emails released this week from a period in which he was working as a visiting professor at the University of Colorado — shed new light on the lengths Trump and his allies were willing to go in pressuring lawmakers in Pennsylvania to take action to secure him a second term and underscores the extent to which some GOP candidates for statewide office in the May 17 primary were involved in those efforts.

Diamond, who has represented Lebanon County outside Harrisburg in the State House since 2015, is one of eight Republicans vying to become lieutenant governor.

The correspondence also provides new insight into the thinking of Eastman, one of the central figures working behind the scenes to provide legal cover for Trump’s efforts to reverse his election loss. The law professor was one of the primary advocates for legal arguments that Vice President Mike Pence could unilaterally set aside congressional certification of Biden’s Electoral College victory — a notion Pence ultimately rejected.

Eastman also pushed swing states like Pennsylvania, Georgia, and Arizona to name so-called alternate slates of pro-Trump electors in an effort to cast doubt on the legitimacy of Electoral College votes cast for Biden in those states.

In March, a federal judge in California described Eastman’s efforts as “a coup in search of a legal theory” and, ruling in a civil case, concluded that Eastman and Trump had most likely committed felonies, including obstructing the work of Congress and conspiring to defraud the United States.

But the batch of Eastman emails released this week, including his correspondence with Diamond, shows for the first time the arguments he made and tactics he suggested to advance those theories in conversations with individual Pennsylvania legislators.

The emails were released under a public records request to the nonprofit Colorado Ethics Institute and were first reported on by the Denver Post and Politico.

In an interview Thursday, Diamond described Eastman as just one of many people from whom he was seeking advice during the period in 2020 in which he and other lawmakers were questioning the outcome of the Pennsylvania race.

He said he first reached out to the law professor after hearing his testimony about the election at a legislative hearing in Georgia but noted that nothing Eastman suggested ever made it into any legislation he proposed.

“When you’re formulating legislation a lot of people throw a lot of spaghetti at the wall,” he said. “What’s important is what gets into the final product.”

The Dec. 4 exchange between Eastman and Diamond occurred during a critical moment in the fevered post-election scramble by Pennsylvania Republicans to stop Biden from being declared the victor in the state, which he won by more than 81,000 votes.

State and federal judges had rejected a series of lawsuits claiming the state’s results were tainted by widespread fraud, noting that despite their serious allegations, Trump and his lawyers had failed to provide evidence of — or even allege — one instance of a fraudulently cast vote.

With that legal effort flagging, the then-president and his Pennsylvania supporters adopted a new strategy — abandoning earlier claims of fraudulent votes and instead challenging as illegitimate the laws under which the state had administered the election.

» READ MORE: Trump and his allies tried to overturn Pennsylvania’s election results for two months. Here are the highlights.

Just days before the Dec. 4 email, a state legislative hearing in Gettysburg — convened by Trump backer and the current GOP primary front-runner for governor, State Sen. Doug Mastriano — provided a raucous platform for advocates of both approaches.

The proceeding featured firebrand speeches from lawmakers questioning the legitimacy of the state’s mail voting law, whooping cheers from supporters, and baseless accusations from Trump lawyer Rudy Giuliani that “Big Tech,” the media, and a “cabal” of Democratic mayors had conspired to steal the election.

Eastman concluded that the Trump team had presented “ample evidence of sufficient anomalies and illegal votes to have turned the election from Trump to Biden” at that hearing. Diamond, however, left the Gettysburg hearing unimpressed, and responded to Eastman that Trump’s lawyers had failed to present a strong case.

“Honestly, the Trump legal team was not exactly stellar at PA’s hearing,” the lawmaker wrote. “[They] failed to provide the affidavits of their witnesses and made a glaring error by purporting that more ballots had been returned than mailed out.”

Eastman offered another suggestion. Noting that the rejection rates for absentee and mail ballots had dropped considerably in 2020 compared to past elections — from roughly 4% to less than 1% — he suggested GOP lawmakers could simply cite “anomalies” in how the elections were administered, apply the old rejection rates to that years’ vote, and substitute those totals for the state’s official count.

Rejection rates do vary from election to election, though, and it’s not accurate to assume previous rejection rates should apply to other elections. For example, one reason rates may have fallen in 2020 is because millions of dollars were poured into educating voters before that year’s election, the first in which a majority of Pennsylvanians were expected to vote by mail, on common reasons ballots might be rejected.

In the end, Diamond ultimately did not act on Eastman’s theory. Instead, he advanced two resolutions early last year that would have declared Pennsylvania’s election results to be “in dispute” and called for Pennsylvania’s Congressional delegation in Washington to challenge the state’ electoral votes on that basis.

The State House did not vote on either resolution, though Diamond.

Justice Department officials have said they are investigating some attempts by Trump allies to influence state legislators in manners similar to Eastman’s.

The Colorado Ethics Institute said it has turned the emails between Eastman and Diamond over to the U.S. House committees investigating the Jan. 6 attack.

Staff writer Jonathan Lai contributed to this article.