"He is planting the seeds for delegitimizing the election if he loses," Vanita Gupta, a former head of DOJ’s civil rights division under President Barack Obama and now president of The Leadership Conference on Civil and Human Rights, said on Twitter on Sunday in reaction to Trump's "rigged election" claim. "It’s from the playbook. It’ll get more intense as he gets more freaked out."

Trump’s rhetoric isn’t exactly new for him. Dating back even before his entry into electoral politics, the president has had a long preoccupation with voter fraud and “rigged” elections. As a primary candidate, he attributed his Iowa defeat to fraud committed by Sen. Ted Cruz. Even after his general election victory, Trump made unsubstantiated claims of “serious voter fraud in Virginia, New Hampshire and California” — three states that he failed to carry — and told congressional leaders that millions of illegal votes were the reason he lost the popular vote.

In one of his first acts as president, Trump created an 11-member commission to study alleged voter fraud. Two years later, amid the GOP’s 2018 wipe-out, he was lodging complaints about “electoral corruption” in Arizona and “missing or forged” ballots in Florida.

The concern that Trump might attempt to ignore the outcome of the election has persisted as an undercurrent in the Democratic Party since 2016, when Trump, during the year’s last presidential debate, refused to say if he would accept the election’s outcome that year if he lost. In the years since, Democrats saw innuendo in Trump’s jokes about extending his presidency beyond the constitutional limit of eight years and expressed admiration for Chinese President Xi Jinping’s limitless terms.

“It’s one of those things that I think has a very low probability, but a very high risk,” said David Skaggs, a former Democratic congressman who has discussed the potential for disruption in the November election with other lawmakers and former lawmakers in recent days. “So even though I don’t think it’s likely to eventuate into some kind of intervention at the state level by the president … there’s still some chance of that, and therefore it’s wise to take it seriously.”

Skaggs said there are people remaining in government who take their oaths of office seriously and “who are not going to be bowled over by a power grab.” However, he noted the presence of a “militia movement out there in the country that would probably rise to arms if the president said they should, and that would be awful.”

“I think the more there is reporting that takes the president’s innuendo seriously about this — the integrity, or the dis-integrity of the election — the more people will be on alert,” he said. “And that is some prophylactic, better than hydroxychloroquine.”

While the unique and uncertain atmospheric conditions this year — an election season rattled by the coronavirus crisis, which has postponed primaries and raised questions about voting procedures on Election Day in November — have served to put critics of the president on edge, it’s his recent threats to withhold funding from Michigan and Nevada that have raised alarms.

Especially significant is Michigan, which Trump won in 2016 but where he is polling behind Biden.

“He’s already set the stage to say it’s rigged,” said Pete Giangreco, a Democratic strategist who has worked on nine presidential campaigns. “This is part of the Trump autocrat playbook … There’s no way this guy’s going to win the popular vote, and it’s at least 50-50 he’s going to lose the electoral college. So, he’s got to come up with something else.”

The Biden campaign is signaling an awareness of the questions it raises. The former vice president told donors at a virtual fundraiser late last month that he is beginning a transition process, saying “the Bush administration worked very closely with Barack [Obama] and me, with our administration, in terms of handing over power in the transition,” according to a pool report.

“I hope it's as smooth as it was then,” he said, adding, “I doubt it, but I hope so.”

Bob Bauer, Joe Biden’s personal lawyer, said in a prepared statement that Trump “may well resort to any kind of trick, ploy or scheme he can in order to hold onto his presidency.”

Tim Murtaugh, a spokesman for Trump's reelection effort, called any discussion about the president’s unwillingness to leave office if defeated “baseless, ridiculous conspiracy talk and they should go see [Democrats] Hillary Clinton or Stacey Abrams because they actually have openly questioned their own election results.”

The Trump administration recently started the process of planning for a transition of power if Biden wins, creating a transition planning group to prepare for the possibility.

But Trump has rarely been encumbered by fidelity to tradition. And Trump’s former lawyer, Michael Cohen, once predicted in congressional testimony that there “will never be a peaceful transition of power” if Trump loses.

“Would I be surprised if he gets beat in November and makes noises about not going out the door? No, and then what kind of constitutional crisis would that create, and then what would you do?” said Mark Longabaugh, a senior adviser to Bernie Sanders during his 2016 campaign.

He likened the prospect facing Democrats to that of the 2000 presidential election, in which the Supreme Court prohibited further recounts of the Florida vote, awarding the presidency to George W. Bush over Democrat Al Gore.

“If it’s narrow, that’s when Trump can really create a constitutional crisis,” Longabaugh said. “Think about the 2000 election, and if that was the election, what would Trump do? And you know, what would Trump do if the Supreme Court went against him? Would he do what Al Gore did and put the interests of the country above his own interests whether or not the Supreme Court was correct in its behavior or not? That’s where you get into, I think, scary territory.”

At a minimum, Democratic doubts about Trump's willingness to accept the November results have increased the imperative to win by indisputable margins — a heavy lift in an election that is widely expected to be close.

"My job is to make sure he loses Wisconsin so badly that he doesn’t have an argument for sticking around that passes the smell test,” said Ben Wikler, chairman of the state Democratic Party in Wisconsin, a state that is critical to Trump’s path to reelection.

Noting that Trump has "filed a lot of lawsuits" in the past, he said, “The bigger the margin, the safer democracy becomes.”

But outside of a court challenge, Trump’s options to disregard the election’s outcome are extremely limited.

“There’s a lot of people that need to do something to hold and implement the results of an election,” said David A. Super, a professor of law at Georgetown University Law Center who has analyzed scenarios in which Trump could attempt to hold onto power. “None of them is named Donald J. Trump … There’s absolutely no authority for cancelling or overriding an election in the Constitution or in the statutes. And it would require the president to get multiple people to fairly blatantly disregard their oaths to uphold the Constitution.”

The concerns about Trump’s intentions are reminiscent to some Democrats of the anxiety they felt in the 1970s, when the net was closing around Richard Nixon and some feared he may not go easily.

The difference, said Les Francis, a former deputy White House chief of staff in the Carter administration, is that Nixon made an “institutional decision” to resign, while “one thing we know about Trump, for sure, is he’s not an institutionalist by any stretch of the imagination.”

“I don’t think there’s any depth to which he will not go,” Francis said. “I don’t think there are any rules that he thinks apply to him. As his behavior grows worse, I think people become more alarmed at the possibilities.”