Wearing a mask as he took the stage on an airport tarmac in Hibbing, Minnesota, Pence returned to the campaign trail Monday despite his chief of staff and four others in his close orbit testing positive for COVID-19 over the weekend. 

"Thank you so much for coming out on this blustery day. And looking out at this crowd, it’s pretty obvious to me the Iron Range is Trump country," Pence said on an afternoon where it was 25 degrees and lightly snowing.

He made no mention of the coronavirus outbreak among his inner circle. Pence’s office said he tested negative this morning for COVID-19.

In his remarks, Pence nodded to the imminent confirmation vote of Judge Amy Coney Barrett, but unlike at his rally in Florida Saturday, he did not indicate he will be in the Senate chamber this evening but on standby in case his vote is needed. 

"When we're done, I'm gonna head back to Washington D.C., just in case they need my vote. But even if they don't, I'll make a prediction: before the day is over, Judge Amy Coney Barrett is going to be Justice Amy Coney Barrett," Pence said to applause. 

There was a strong focus on the Iron Range during Pence’s remarks, telling families across the area that "our bridges and skyscrapers soar because of iron that comes out of the Iron Range."

In 2016, Trump lost Minnesota by only 2 points and has been making a push to try to flip the state this year. Pence acknowledged how tight that race was and asked supporters to keep making a final push in these final days.

"I’ll always believe the greatest form of media in this country is not your TV networks, it's not your big newspapers, it's not even your social media. I think it’s word of mouth. I think you know we came so close in Minnesota, right? Last time around because people were talking to each other. I mean we made history in this country in 2016," Pence said. "And you got to go do it again, you got to deliver this time again."

Pence put his mask back on when he wrapped his remarks and ran back to his plane for Washington.

-ABC News' Justin Gomez

After the Biden campaign had announced no public events for the day, he visited with supporters at a voter field office and activation center in Chester, Pennsylvania, in Delaware County, while Trump also rallied in the battleground state, and delivered impromptu remarks attacking the president's response to the pandemic. 

"What in the hell is the matter with this man?" Biden said, arguing the Trump administration is "giving up" on its response as Trump insists cases are "leveling out" when they’re actually on the rise. 

"I'm not going to give up. I don't know what we'll inherit on January 21st, but at the rate he's going it's not going to be good," Biden continued.

Asked about the outdoor event the White House is planning tonight to celebrate the anticipated Senate confirmation of Judge Amy Coney Barrett to the Supreme Court, Biden said it sets a bad example to all Americans when the president holds "superspreader events."

"I just hope he is willing to have learned a lesson and there will be significant social distancing. I don't blame him for celebrating. There's a lot of things we could be doing having massive crowds, but the fact is that it's just not appropriate now," Biden said. "It shouldn't be a huge crowd, whether it's outside or not."

Defending himself against criticism from Trump that he’s in "hiding" in the final days of campaigning, Biden noted he’ll be visiting Iowa, Wisconsin, Florida and Georgia this week but also took the chance to differentiate his campaign events from Trump’s. 

“We're going to be traveling -- continue to travel, but the big difference between us -- and the reason why it looks like we're not traveling, we're not putting on superspreaders,” Biden said. “We are doing what we're doing here. Everybody's wearing a mask and trying as best we can to be socially distanced and that’s what we do."

At the second of three events in Pennsylvania Monday, Trump told supporters at a rally in Lititz while he wants any transition to be done "absolutely by the book" but that it’s "very hypocritical" for Democrats and other critics to expect a friendly transfer of power.

"We want it to be done absolutely by the book, and we want to go absolutely by our great Constitution. But you know what, when they start talking about this friendly wonderful transition. And then you see what they put us through. It's really very hypocritical isn’t it?" Trump told the fired up crowd. "On November 3rd we must finish the job and drain that very deep and very nasty swamp once."

Ticking through the battleground state Monday, Trump urged voters to turnout in stronger numbers than in 2016 as he narrowly won the state then by only .72%.

"For the last four years, you've seen me fight for you and now I am relying on you to deliver a historic victory for our country. Bigger even than four years ago," Trump said.

Trump continued to brush off the effects of COVID-19 as cases and hospitalizations rise across the country, saying, "One day you get it, and, that's OK. You get better. We have such great, I think, cures." He again raised the diagnosis of his youngest son, Barron, 14, to downplay the effects of the disease on children. According to the latest report from the American Academy of Pediatrics, at least 120 children have died from COVID-19 since late March. 

"I mean, I got it and I'm here. We have great medicines and therapeutics," he said. “You know who else got it? Barron. My very tall son… It’s gone. Young kids, they have a strong immune system. I've gained such respect for them.”

“It's absolutely an amazing thing what we've done in a period of seven months because, you know, I'm the president of the United States,” Trump added. 

Some Amish supporters, without masks, stood directly behind Trump at the rally, and the demographic received a nod from Trump.

“We have Pennsylvania Dutch. Don't tell anyone. You know, they -- they’re great people. They're great people, but they're not known for going out and voting for a lot of reasons. Don't tell anybody, but the Pennsylvania Dutch are voting en masse,” Trump said. 

In slamming trade positions taken by the Obama administration, Trump also said he wants the U.S. to be a “developing nation” as the World Trade Organization still recognizes China as a developing country.

“They are considered a developing nation and I said so we are a developing nation, too. We’re developing, they are developing, we are developing, they get big advantages,” Trump said. “We want to be a developing nation also.”

Democratic vice-presidential nominee Kamala Harris, the first woman of color on the ticket of major party, responded to attacks and slights she's endured from Trump, including mispronouncing her name and referring to her as a "female socialist," during an interview with ABC's "The View."

"It's so predictable coming from him. I mean it's childish, it's name-calling on behalf of the president of the United States, and, again, the American people deserve so much more from their president," said Harris. "You know, look, the name-calling is not new to me -- it's not new to anybody who played on the playground as a child. But this is not the playground."

She also took the opportunity to ease concerns around Biden's stance on fossil fuels after Biden said at the last debate he would transition from the oil industry overtime and end fossil fuel subsidies, and the Trump campaign seized on the comments.

"Without any ambiguity, Joe is clear. We will not ban fracking. And let's clear up further things and we will not raise taxes on anyone making less than $400,000 a year, period, full stop," said Harris. “Joe is also committed to understanding that we have to also acknowledge the science in a way that frankly the current president does not, on the COVID issue and on climate."

Harris will travel to Nevada on Tuesday, and according to a source familiar with plans, she will be in Texas on Friday -- the first Democratic vice presidential candidate to campaign in the state in decades -- as Democrats eye the GOP stronghold. Texas currently leads the nation with the largest number of early votes. 

-ABC News’ Averi Harper