Sen. Kamala Harris made a second stop in Texas on Friday evening, where she was joined on stage by former Texas Rep. Beto O'Rourke and former San Antonio Mayor Julian Castro at a drive-in rally in McAllen.

The Democratic vice presidential candidate gave her typical stump speech drawing contrast between Joe Biden and President Donald Trump on multiple fronts, with emphasis on what she described as Biden's ability to unify Americans. 

"Joe Biden, in his heart, knows who we really are as America. Joe Biden, in his heart, knows that regardless of where you live, your race, your gender, your age, the language your grandmother speaks -- Joe Biden knows that the vast majority of us have so much more in common than what separates us. And it is time that we reject hate and division, and unify as a country. There are clear choices," she said.

-ABC News' Averi Harper

At his stop in St. Paul, Minnesota, former Vice President Joe Biden battled with noise from Trump supporters as he took aim at the president.

Talking over a constant stream of air horns and beeps, the Democratic nominee responded to President Donald Trump's claim at a rally earlier Friday that doctors inflate the number of deaths from COVID-19 to get more money.

"The president of the United States is accusing the medical profession of making up COVID deaths so they make more money," Biden said. "Doctors and nurses go to work every day to save lives. They do their jobs. Donald Trump should stop attacking them and do his job."

Biden addressed the noise three times during his remarks. At one point, he referred to those "ugly folks" blasting horns and attempting to interrupt the event.

"Dr. [Anthony] Fauci called for a mask mandate last week. This isn't a political statement like those ugly folks over there beeping the horns," Biden said. "This is a patriotic duty, for God's sake. Look, in his own words, as I said, the president knew back in January how extremely dangerous and communicable this disease was."

Biden pleaded with voters to keep themselves engaged in the final four days of the race -- once again taking a jab at the loud protesters as he did so.

"Right here in Minnesota, with all of you, in the final days, keep that sense of empowerment. Keep that -- empowerment with you, that sense of optimism, of what we can overcome," he said. "Now look, there's a reason they don't want to hear me, because they know the president doesn't say anything. So they're not used to not hearing anything."

Toward the end of his remarks, Biden pointed to a recent appellate court ruling that absentee ballots received after Election Day cannot be counted, and urged everyone to hand-deliver their ballot rather than mail it.

"So if you want your voice to be heard, drop off your ballot. Don't put it in the mail. Or vote safely in person any day up through Election Day," he said. "But you've got to get it done. And make sure everyone you know votes as well, so they'll not be able to stop us."

-ABC News' Molly Nagle

At his second rally of the day, President Donald Trump spoke to supporters on a chilly day in Green Bay, Wisconsin.

As he has at every rally recently, the president attempted to downplay the threat of COVID-19 and said the U.S. is "rounding the turn" on the pandemic, despite the country facing a third wave of cases and hospitalizations surging around the country.

Coronavirus cases, hospitalizations and deaths are particularly on the rise in Wisconsin. On Friday, the state reported more than 5,000 new cases, and almost every county is experiencing "very high disease activity," including Brown County, where Green Bay sits, state health department data shows.

Wisconsin Gov. Tony Evers has called the surge an "urgent crisis" and has asked people to stay home.

While in Wisconsin, Trump made it very clear that if "we win this state ... it's over."

He also continued to blast this week's ABC News/Washington Post poll, which found him down 17 points to Biden among likely voters in Wisconsin.

"I said, wait a minute, I just left a crowd of 25,000 people or more," said Trump, referring to a rally earlier this week in West Salem. "They were going crazy. That wasn't a second-place crowd. You know, we know a second-place crowd. That was not a second-place crowd."

-ABC News' Terrence Smith, Elizabeth Thomas and Will Steakin

At his first of two stops in Arizona on Friday, Vice President Mike Pence threw his support behind congressional candidates and told Arizonans to elect them so House Speaker Nancy Pelosi, D-Calif., can be removed from her post.

"So right after you reelect President Donald Trump for four more years and right after you reelect Sen. Martha McSally to the United States Senate, we all need you to send Paul Gosar, Congressman Markwayne Mullin and Tiffany Shedd to a new Republican majority in the House of Representatives, and retire Nancy Pelosi once and for all. Out! She has got to go," Pence said at the outdoor rally in Flagstaff.

That caused some supporters to chant "lock her up!"

Mullin, it should be noted, is not on the ballot in Arizona, but represents Oklahoma's 2nd Congressional District.

McSally, who is competing in one of the most-watched Senate campaigns this cycle, introduced Pence. The vice president said it was "an honor" to share the stage with her, and that she has "emerged as one of the greatest champions" for Republicans.

On the coronavirus, Pence said that a vaccine is "just a short time away." He acknowledged that COVID-19 cases are increasing in the state, which reported 1,565 new cases Friday.

"And as we see cases rise, particularly across the heartland and even somewhat here in Arizona," he told of the crowd of about 500, the majority of whom were not wearing masks or social distancing. "I want to assure you, we're going to continue to move heaven and earth to make sure that our doctors and nurses, and here in Arizona and everywhere in America, that every family has access to the health care that we'd want any member of our family to have."  

-ABC News' Justin Gomez

Returning to the state for the first time since campaigning in the Iowa caucuses, Biden made his argument against Trump’s handling of COVID-19 directly to Iowan voters at a drive-in rally this afternoon, emphasizing the jobs lost in Iowa because of, he said, Trump’s unwillingness to deal with the pandemic.

“Eighty-two thousand Iowa jobs lost in the pandemic, and still, they've not come back. Seventy-thousand jobs lost in Iowa since Donald Trump became president. Here at the fairgrounds, the Iowa State Fair cancelled for the first time since World War Two. Donald Trump has given up," Biden said to honking horns of support.

The former vice president repeated his campaign promise that he wouldn’t raise taxes on those making less than $400,000 a year, but said big corporations -- and the president -- will pay their “fair share” in a Biden administration.

"Why should a firefighter, an educator, a nurse, a cop pay at a higher tax rate -- which you do -- than a major multi-billion dollar corporation? Why should you pay more taxes than Donald Trump, who paid $750?" Biden said, referring to a New York Times report. "Well, you ain't going to be gaming the system anymore in a Biden administration. They're going to start paying.”

The race in Iowa is neck and neck with Trump leading by one point according to a Quinnipiac poll published Thursday -- remarkable given that Trump won the state back in 2016 by 10 points. 

While the state only has 6 electoral college votes, it holds a key demographic of Trump's base: farmers. And Biden catered his argument in Des Moines to that key base, arguing he can end trade abuses by China harming their industry, not Trump.

“He [Trump] says, because of, quote, his bailouts, ‘our farmers do better now than when they actually had a farm,’” Biden said. “Look, I'll do what he's been unable to do. I'll mobilize a true international effort to stop China's abuses, so we can strengthen manufacturing and farming in Iowa and across the country.”

In 2016, Trump’s strength in rural counties propelled his victory in Iowa, which saw the largest swing away from Democrats among the six states that flipped from former President Barack Obama to Trump. But Biden also made clear his close relationship to Obama, reminding Iowans they led them to the White House in 2008 and 2012.

"You, too, have a sacred duty -- a duty to vote. It matters," Biden said. "Iowa matters."

-ABC News’ Lauren Lantry contributed to this report.