Vice President Kamala Harris and former president Donald Trump took their fight for the crunch election battleground of Pennsylvania to opposite ends of the state with rival campaign events only three weeks before polling day.
Ms Harris spoke in the northwest corner in Erie on Monday night, while Trump was in the southeastern suburbs of Philadelphia.
The candidates have been making regular appearances in the country's largest battleground state - it was Ms Harris' 10th visit to Pennsylvania this campaign season, while her Republican rival made stops in Scranton and Reading last week.
At an evening campaign rally, the vice president homed in on Trump's comments over the weekend suggesting that the US military could potentially be used to deal with "the enemy from within".
She argued the comments made in a Fox News interview are the latest example of threatening rhetoric from the former president that should concern Americans about what a potential second Trump term could look like.
"He considers anyone who doesn't support him or who will not bend to his will an enemy of our country," she said after playing a clip of the comment on the jumbo screen in the Erie arena. "This is among the reasons I believe so strongly that a second Trump term would be a huge risk for America and dangerous."
She added that Trump is increasingly displaying "unstable and unhinged" behaviour.
Trump made the comment in response to a question about "outside agitators" potentially disrupting election day, pivoting to what he said is a foe closer to home.
"I think the bigger problem is the enemy from within," Trump said. "We have some very bad people. We have some sick people, radical left lunatics... and it should be very easily handled by, if necessary, by National Guard, or if really necessary, by the military, because they can't let that happen."
Running mate Senator JD Vance defended Trump's comments during a campaign stop in Minneapolis earlier on Monday.
"Is it a justifiable use of those assets if they're rioting and looting and burning cities down to the ground? Of course it is. Right?" Mr Vance told reporters.
"I think the question is, is it a justifiable use of assets, depends on what's actually happening."
Trump beat Hillary Clinton by more than 40,000 votes in Pennsylvania on his way to winning the presidency in 2016. But President Joe Biden, a Scranton native, beat his rival by about 80,000 votes in the state four years ago.
Ms Harris' called Erie a "pivot" area for her campaign, a Democratic-majority city of about 94,000 people bordered by suburbs and rural areas with significant numbers of Republicans. Erie County is often cited as one of the state's reliable bellwether regions, where the electorate has a decidedly moderate voting record. Trump visited Erie on September 29.
She also talked up early voting during her rally. Mail-in voting is well underway in the state where some seven million people are likely to cast votes in the November 5 presidential election.
"If you have already received your ballot in the mail, please do not wait," she urged her supporters. "Fill it out and return it today or tomorrow. But please get it out."
Beforehand, she stopped by a newly opened coffee shop and record store in Erie as she continues to press her case for black men's support.
The visit to LegendErie Records and Coffee House, a black-owned small business, came after her campaign unveiled a plan earlier Monday to give black men more economic opportunities and other chances. The campaign is trying to step up outreach to black men, a key voting bloc that has some Democrats concerned about a possible lack of enthusiasm.
Trump spoke at a town hall on Monday in suburban Oaks.
Responding to a man who said his dream of homeownership feels out of reach, he said regulations make it too expensive to build in some places. He repeated his pledge to increase US oil drilling, which he said would drive down costs, though domestic production is already at record highs.
"We're going to drill baby drill, we're going to have so much energy and we're going to bring prices down," he said.
He also claimed government data from crime statistics to jobless numbers is "fake", alleging the numbers are manipulated to help the incumbent Democrats.
Trump cut short his remarks after twice being interrupted by medical emergencies, turning the town hall into a concert instead. After the second incident, he spoke for a few more minutes and then called for music, standing on stage - at times swaying along - as music played.
