Updated at 4:49 p.m. ET
Democratic nominee Joe Biden called President Trump's refusal to commit to a peaceful of transfer of power if he loses the election "a typical Trump distraction."
"I'm confident that [despite] all of the irresponsible, outrageous attacks on voting, we'll have an election in this country as we always have had," Biden said in an interview Friday with MSNBC. "And he'll leave."
The former vice president also said "it will be clear from the beginning where this is going," a contrast with the warnings of many election experts who say the public should brace for days of uncertainty if the election is close.
Biden said he is confident in the courts, Congress, the military and national security agencies to carry out the rule of law.
"The last thing we need is the equivalent of a coup," Biden said. "I mean, this is not who we are. No one's going to back him when that occurs, if that were to occur. I think ... the whole notion of him talking about this ... is to take our eye off the ball, not to talk about what's happening to the people dying."
However, Biden said he has considered that Trump could continue to sow doubts about the validity of the results, even after election night.
"What I am concerned about is whether he generates some kind of response in a way that unsettles the society or causes some kind of violence," Biden said, imagining a scenario where Trump claims victory on election night before all the mailed ballots are counted.
"But I don't think it's going to go anywhere," Biden said. "I think the American people are onto this guy."
Others seem more concerned about Trump's comments.
In a major speech Thursday, Sen. Bernie Sanders of Vermont warned that Americans of all political persuasions need to take the president's words seriously and prepare to stand up for American democracy.
"This is not just an election between Donald Trump and Joe Biden," Sanders said. "This is an election between Donald Trump and democracy — and democracy must win."
White House doubles down
Meanwhile, White House escalated its sandblasting of U.S. democratic practices on Friday when chief of staff Mark Meadows criticized and mocked the FBI director's assurances about the integrity of this year's presidential election.
Meadows told CBS News that FBI Director Christopher Wray doesn't know what's happening on what the chief of staff called "the ground" when Wray affirms, as he did Thursday to the Senate, the absence of coordinated fraud in mailed ballots.
Meadows alluded to long-running Republican attacks on federal law enforcement in faulting Wray for his responsiveness and his testimony.
"With all due respect to Director Wray, he has a hard time finding emails in his own FBI, let alone figuring out whether there is any kind of voter fraud," the chief of staff told the TV network.
Wray and other intelligence community leaders have been at pains to walk a tightrope between warning Americans about what they call the legitimate perils facing the 2020 presidential race from foreign interference and those for which they say there's no evidence — such as widespread mail ballot fraud.
The FBI director described this dynamic to the House earlier this month and repeated as much Thursday to the Senate, which irked Meadows and Trump. Wray's testimony conflicts with their messages of criticism about alleged fraud, and Trump also criticized Wray after his earlier appearance.
Trump has made baseless claims about alleged voter fraud for years, including ones that a panel he appointed couldn't substantiate, but he and supporters have nonetheless sustained a running soundtrack of cynicism and suspicion about elections practices.
This week, Trump initially didn't agree that he'd accept the results of an election in which he lost, the White House sought to walk back those remarks, and then Trump restated what he called his uncertainty that this year's race would be legitimate.
Nuanced picture lost in sound bites
Fraud, mishandling or other problems with ballots are rare in the broad scheme of U.S. elections but not nonexistent — and Trump and supporters have sought to play up anecdotal examples as part of their long-running commentary about alleged mischief or the untrustworthiness of the U.S. election system.
The latest case emerged Thursday in Pennsylvania, where county workers — primed to be on guard by warnings about election security — escalated a local office slip-up over a small number of mailed ballots into a federal investigation.
The county's district attorney, who is on a task force impaneled by Attorney General William Barr, referred the matter to the local U.S. attorney, David Freed, whom Trump nominated.
The case didn't rise to national attention because of an indictment unsealed by Freed at the conclusion of an investigation that found wrongdoing. It got into the news cycle from Washington after Trump and other White House officials discussed it.
Justice Department veterans and Barr have restated what they call the importance of not announcing or discussing investigations while they're underway, citing what's been called the disruptive example, among others, of FBI Director James Comey in the 2016 election.
Even so, Freed's office issued a press release on Thursday announcing it had become aware of the small problem within the Luzerne County Board of Elections.
Skeptics saw a strategy at work: surface an anecdotal case of mail ballot problems that supports the White House's line and creates another apparent dot in the scatter plot about the alleged untrustworthiness of this year's election.
According to a statement by the county Friday, an independent contractor employed by the office to sort mail accidentally threw about nine ballots in the trash.
When the elections director found them, she immediately began an inquiry and the contractor was fired. The elections staff did not know for whom the ballots had been cast until reading a press release from the U.S. attorney's office.
The New York Times reported on Friday that Barr briefed Trump about the Pennsylvania case.
Calls for caution
David Thornburgh, leader of the nonpartisan election watchdog group Committee of Seventy, told reporter Katie Meyer of NPR member station WHYY that Americans should guard against reaching any conclusion from any single episode or event.
Sometimes what looks like "the tip of an iceberg" isn't an iceberg at all, he said.
Prosecutors' ability to shade public perceptions about a suspect or an investigation is one reason they're supposed to keep silent about cases until the appropriate time, other commentators said.
6/Going forward, the Justice Dept. should focus on finishing the investigation to help ensure that every eligible vote is counted. Publicizing investigation updates with incomplete facts and/or preliminary findings close to an election is risky at best and dangerous at worst.— David Levine (@davidalanlevine) September 25, 2020
"Going forward, the Justice Dept. should focus on finishing the investigation to help ensure that every eligible vote is counted. Publicizing investigation updates with incomplete facts and/or preliminary findings close to an election is risky at best and dangerous at worst," wrote David Levine, a former elections supervisor who's now elections integrity fellow with the Alliance for Securing Democracy.
Real threats versus political commentary
The political countermoves and narrative-framing is taking place against the backdrop of real threats to the election, national security officials said.
The FBI and Cybersecurity and Infrastructure Security Agency have warned about the prospect, among other things, about sabotaged or fake election results reporting in the hours or days after voting ends, which could heighten the tension of a close result.
House Minority Leader Kevin McCarthy, R-Calif., waved off concerns about Trump's comments and Americans' confidence in the election in a press conference Thursday. The likeliest scenario, he argued, is that Trump wins and simply moves on to a second term, obviating all the back-and-forth about the integrity of the vote.
Other critics, including some who served within the Trump administration, argue the president has betrayed his office by seeking to erode Americans' faith in their own system, including with criticisms that chime closely with those of its adversaries.
Trump's willingness to "rely on the words of dictators like Vladimir Putin is an unprecedented betrayal to his oath to the Constitution," wrote Robert Cardillo, former director of the National Geospatial-Intelligence Agency, in a column Friday.
"Our current president bases his decisions on his instincts, and his instincts are based upon a personal value proposition — what's in it for me?"