As you walk around America's capital Washington DC, the city looks like it's preparing more for a riot than election parties.
Shops are boarding up their windows, authorities are readying their defences against violent demonstrations, and an 'anti-climb' wall is being built around the White House.
Tourists, once able to stand outside the White House fence for a clear view of the historic residence, have been pushed back to surrounding streets, and the view is blocked by barricades and a heavy police presence.
The Executive Office of the President has become even more fortified, with multiple layers of high chain link fencing, concrete vehicle barriers and a security perimeter that keeps expanding.
Election night is just days away, and the mood around the city — and the country— is tense.
City and law enforcement officials are bracing for two anxiety-inducing scenarios: clashes on the streets and at polling stations.
The wall around the White House was erected in July, after the death of George Floyd triggered nationwide protests against the treatment of unarmed black people by police.
Many protests deteriorated into rioting and looting, and in some cases, shootings.
Police officers, their vehicles and buildings were attacked and law enforcement officers themselves were accused of brutality in a multitude of incidents.
Often trouble came from outside agitators, with anti-government and anti-law enforcement agendas in a confusing, toxic brew of chaos that is contributing to the current anxiety about election night.
The Secret Service prepares for violence
Nowhere is security likely to be tighter than in Washington DC, where Mr Trump's campaign is promising an election night "victory" party at the Trump International Hotel, five blocks from the White House on Pennsylvania Avenue.
The capital has more than two dozen law enforcement agencies with overlapping jurisdiction.
The US Secret Service is responsible for safeguarding the President and his family, the White House and its perimeter, and its agents will be coordinating with a broad cross section of law enforcement officers.
Officers from the US Capitol Police, Metropolitan Police Department, National Parks Police and other agencies will be part of the planning rubric, along with local emergency services.
Former veteran Secret Service agent Don Mihalek said the violent protests in Washington DC and other US cities this year have taught law enforcement officers to prepare for an escalation of events at protests.
"Unfortunately, expecting violence is now part and parcel of the situation. If and when riots occur is always a question," Mr Mihalek said.
"If they occur, officers have to anticipate that they might be attacked by rioters. How are they going to deal with it? It's front and centre of any planning right now."
His concern is not with Americans exercising their constitutional right to protest peacefully.
"My concern is the response of radical protesters who undermine our democracy and conduct violence, burning buildings and attacking law enforcement. They come armed and ready to attack police officers."
He expects wide road blocks around the Trump Hotel and the White House, and zero tolerance from law enforcement officers for armed protesters or militia.
Washington DC is one of only a handful of US jurisdictions that prohibit the open carrying of weapons.
"Armed militia are not getting anywhere near Trump Hotel or the White House. Anyone armed that shows up would risk spending time in jail, or worse," Mr Mihalek said.
"They'd be taking their life into their hands that night."
Fears of violence at the polling booth
There are also concerns about the potential for confrontations or attempts to intimidate voters when they try to cast their ballots, especially in swing states where vote counts may be extremely close.
President Trump has urged his supporters to "go into the polls and watch very carefully", while his campaign has released a video urging them to look for tell-tale signs of suspicious behaviour.
"You're looking at body language," the video says.
"If you see a confused look on a voter's face or a confused look on a poll worker's face, or any kind of delay in the process, there's your clue."
Michael Chertoff, the former Secretary of Homeland Security under Republican President George W. Bush, ridiculed the video during an interview with CNN.
"I think that's utter nonsense. This is an effort to create disturbances and intimidation," Mr Chertoff said.
As the President prepares for the possibility of a contested election, current and former security officials including Mr Chertoff are trying to instil confidence in voters.
"The good news is many of the jurisdictions, they are aware of this effort and they realise in many cases these efforts violate state law and they have been preparing themselves to take action against people who are misbehaving at polling places," he said.
But a recent poll found fewer than one quarter of Americans believe the election will be free and fair.
Among those polled, 50 per cent of Trump supporters say the election won't be fair and 37 per cent of Biden supporters agree.
In the home stretch, hundreds of lawsuits challenging voting rules around the country are still before the courts, and may yet help determine the election winner.
If cases end up going to the Supreme Court, they will be decided by a new conservative majority of Supreme Court Justices, with President Trump's latest nominee, Judge Amy Coney Barrett newly confirmed to the bench.
Election judges will be on watch
Election judge Julie Hughes will be among hundreds of thousands of authorised workers deployed across the US to safeguard voting at polling stations on November 3.
She has spent more than 30 years working abroad in democracy development, including in South Africa, Zimbabwe, Malawi, Egypt, Iraq and Libya.
In 2013, Egypt sentenced her and other activists in absentia to a five-year jail term for her work promoting democracy.
But this US presidential election is the first time her friends overseas have called to ask her if she's OK.
"I used to think democracy was this inevitable force in the universe, but democracy is a lifelong struggle to maintain representative government," she said.
Ms Hughes expects there will be voter intimidation efforts at some stations.
In her state of Maryland, an equal number of election judges who identify with the political parties are placed at the polls, and while they're not really 'judges' they are called on to handle minor disputes.
Incidents of violence or allegations of vote tampering would immediately go to the onsite chief judge, who would decide what response was required.
President Trump has been sounding the alarm on voter fraud since he was candidate Trump in 2016.
Post-election, he made unproven allegations that millions of people voted illegally for Hillary Clinton, to help explain why he lost the popular vote to her.
When he took office, he established a White House Commission to investigate voter fraud, only to abruptly shut down the commission after finding there was no evidence of widespread voter corruption.
"For the first time, we have a President of the United States saying our elections are fraudulent and the results rigged and that casts doubt on one of the basic tenets of the democracy," long-time Republican election lawyer Benjamin Ginsberg said.
"There is a requirement you would think, on the President of the United States going to make that statement, to have some proof of it and that's not there."