President Trump’s bid to discredit the integrity of the U.S. election results and use legal action to block the completion of vote tallies in some states has raised fears, even among his own aides, that he will refuse to concede and seek to undermine a potential transfer of power after Joe Biden’s victory Saturday.

Trump associates have said privately that the president is unlikely to formally concede the race under any circumstances in the traditional manner of a concession speech and a phone call to Biden.

And though some aides have suggested that they are hoping to convince him to publicly commit to a peaceful transition, experts warned that Trump could work to scuttle cooperation with Biden’s team in ensuring a smooth turnover of the management of the federal government on Inauguration Day come Jan. 20.

“I WON THIS ELECTION, BY A LOT!” Trump tweeted Saturday shortly before all major news organizations called the contest for Biden.

“Donald Trump is behaving like a tin-pot dictator who just lost power and refuses to accept the results,” presidential historian Douglas Brinkley said.

“Trump could be like Bartleby the scrivener and say, ‘I prefer not to leave the presidency.’ That is unprecedented in history,” he added, referring to a Herman Melville story about a legal aide who is forcibly removed after refusing to do his job.

Trump spent months impugning mail-in voting as fraudulent before, in the early hours after Tuesday’s election, falsely citing the ongoing counts in Pennsylvania and Arizona — which Biden flipped after Trump won them in 2016 — and Georgia, which is headed for a recount, as evidence that he was right. Public officials in those states have said there is no evidence of widespread fraud affecting the counts, and they are rigorously investigating individual allegations of wrongdoing.

Trump has dispatched a team of lawyers and White House surrogates to the contested states to challenge the integrity of some ballots, halt the counting of others and seek statewide recounts. He delivered eviscerating remarks about the election system from the White House briefing room on Thursday — one laced with so many falsehoods that TV networks cut away from their live coverage while he was still talking.

White House spokesman Judd Deere emphasized that transition coordination with Biden’s team has been underway for months as required by federal law. Biden’s transition team already has been granted 10,000 square feet of office space at the Commerce Department.

Trump “will accept the results of a free and fair election,” Deere said. “The Trump Administration is following all statutory requirements.”

As of midday Saturday, however, there was no sign of an acknowledgment of Biden’s victory from Trump or the White House.

Biden and his aides have ramped up warnings that they will not wait for Trump to accept defeat. In remarks late Friday, Biden asked the nation to be patient as the votes were counted but made clear he was on track to victory.

“While we’re waiting for the final results, I want people to know we are not waiting to get to work done and start the process,” he added, noting that he and running mate Kamala D. Harris met a day earlier with public health experts to discuss the coronavirus pandemic, which has killed more than 236,000 Americans.

Biden campaign spokesman Andrew Bates was more pointed, reacting to reports that Trump would refuse to concede by saying that “the American people will decide this election. And the United States government is perfectly capable of escorting trespassers out of the White House.”

Transition experts said it will be crucial for Biden to gain quick and full cooperation from Trump’s team. Under the Presidential Transition Act of 1963, the formal transition would begin once Emily Murphy, the Trump-appointed head of the General Services Administration, ascertains that a winner has been determined.

That would greenlight a series of mandatory steps in which Biden’s transition would gain access to federal funding and additional federal office space, along with access to government agencies and briefing materials.

A team of about two dozen GSA officials, most of them career civil service workers, would help oversee the process, experts said.

In 2000, during the contested election between George W. Bush and then-Vice President Al Gore, the transition was delayed 36 days, launching in mid-December after Bush won a legal battle at the Supreme Court and claimed victory.

In a memo on the importance of a smooth transfer of power, the nonpartisan Center for Presidential Transition cited the Sept. 11, 2001, terrorist attacks during Bush’s first year in office and noted that his national security team was not fully in place until the late spring and summer of that year.

An expert who has worked closely on presidential transitions said that the challenge is particularly daunting given the coronavirus pandemic, citing federal efforts to help private companies develop, test and, ultimately, distribute a vaccine.

“The stakes are just incredibly high to have a smooth and peaceful transition. Our national security depends on it,” said this person, who spoke on the condition of anonymity because the election had not yet been called at the time the person was speaking.

“The tone at the top is really, really important,” said the person, adding of Murphy, the GSA administration head: “I think she’ll be in a tough position. She’ll see what the right thing to do is and have political pressure not to do it.”

House Democrats have criticized Murphy, who was unanimously confirmed by the Senate in 2017, over the GSA’s oversight of the Trump International Hotel, which is leased on federal property. Some raised questions over whether Trump had pressured the GSA to scuttle plans to relocate the FBI headquarters out of the city and redevelop its property because the president was concerned that a new development would compete with his hotel. Murphy has said she was not involved in the decision.

Former GSA officials emphasized that the agency strives to be apolitical and that the staffing of career officials in the transition unit will help shield it from potential White House pressure.

But Trump allies have already taken to social media to baselessly accuse the president’s aides, including Cabinet officials, of illegally cooperating with Biden’s team.

Democrats expressed concerns that Trump, even if he ultimately leaves office peacefully, is intent on doing as much as possible to set back Biden’s presidency and make it more challenging for him to manage the government during an ongoing crisis.

“What’s interesting is that Trump is now the leader of the resistance,” said Simon Rosenberg, founder of the liberal NDN think tank. “He can do a lot to make it far more difficult under what is already very difficult circumstances because of covid. He’s going to create a powerful logic for a third to 40 percent of the country that Biden’s presidency is illegal from the start, and he’s working really hard to continue to build that narrative.”