Also largely gone are the seemingly endless string of massive rallies that buoyed his candidacy in 2016 and propelled him from outsider to front-runner.
Biden's team feels this approach aligns with the former vice president's view on the virus and commitment to following federal guidelines on virus safety, helping distinguish him from the president, who has taken an uneven, dismissive and sometimes flippant approach.
Some Democratic strategists say Biden's move is risky, given the power and longevity of Trump's ground game, but others say he has a number of options available, including phone calls and enlisting networks of voters to do the work for him, that could make the difference.
The Trump approach couldn't be more different. Last weekend alone, as part of the Trump campaign's "100 Days Out Weekend," the Trump team held at least 70 events ranging from veteran outreach to voter registration drives from Mohave County, Arizona, to Madison, Maine, according to the Republican Party's public schedule.
Events have featured varying levels of safety precautions. Many do not implement social distancing while some do, and no Trump campaign events nationwide require masks to attend, according to multiple sources.
When asked about safety measures taken at these events, the campaign did not provide specific details. Instead, deputy national press secretary Ken Farnaso said in a statement, "The safety of attendees is very important to the campaign and we take precautions to protect people's health." Adding, "President Trump is utilizing every avenue available to communicate directly with the American people while Joe Biden is hiding to avoid accountability for his abysmal record that spans nearly 50 years."
In July alone, the Trump campaign hosted two "Women for Trump" bus tours, featuring top campaign surrogates, including senior Trump campaign advisers Lara Trump, Mercedes Schalpp and Katrina Peirson.
The bus tours, an effort by the president's team to reach out to women -- 67% of whom disapprove of his coronavirus response, according to an ABC News/Ipsos poll -- hit key battleground states like Maine, New Hampshire and Wisconsin.
Pence emerges as key campaigner
The Trump campaign has also launched Vice President Mike Pence to multiple battleground states this summer, using him as the in-person messenger for smaller events.
Pence, whom the president put in charge of the White House coronavirus task force, held a "Cops for Trump" event in Pennsylvania's Westmoreland County on Thursday and spoke to an overwhelmingly maskless crowd. The event was held in a parking lot next to the Greensburg police station and supporters were standing shoulder-to-shoulder. Those who were seated were separated by an arm's length at most.
The task force currently lists Westmoreland County as a "yellow zone" and explicitly states that in Pennsylvania, "mask mandates must remain in place." According to White House coronavirus task force guidelines, a "yellow zone" is an area that in the last week "reported both new cases between 10-100 per 100,000 population, and a diagnostic test positivity result between 5-10%."
Hours later, the president urged Americans not to attend similar events. "If you can, you have to avoid crowded places," Trump said. "It just seems like some things are taking place in crowded places. We don't want that."
Pence also kicked off a "Faith in America" tour in Wisconsin at the end of June, a state that Trump unexpectedly and narrowly won in 2016. Stops in Florida and Arizona were also scheduled but were ultimately scrapped as coronavirus cases soared in those areas.
The vice president revisited Wisconsin on July 17 where he delivered a scathing attack on Biden, labeling him a "Trojan horse" for the "radical left" and "nothing more than an autopen president." Wearing blue jeans and cowboy boots, Pence also stopped by a dairy farm in Onalaska to promote the United States-Mexico-Canada Agreement, a signature Trump achievement that the president believes will help American farmers and workers.
As Pence traveled around the country for personal COVID-19 briefings from state leaders and education roundtables to discuss safely reopening schools in the fall, he also carved out time for fundraising.
During a trip to Indiana on July 24, Pence hosted a fundraiser for Republican attorney general candidate Todd Rokita, and the following day in Massachusetts he attended a high-priced lunch at the home of Robert Reynolds, CEO of Putnam Investments, for the Trump/Pence reelection campaign.
Canvassing in a pandemic
The Trump campaign sees its ground game as a key advantage three months out from Election Day and is showing no signs of slowing down despite rising cases in dozens of states. And because Trump is the incumbent, his campaign was able to build out key battleground state teams for well over a year, with staffers on the ground in crucial swing communities long before Biden's campaign started announcing state staffing positions.
In a conference call with reporters last week, new Trump campaign manager Bill Stepien pointed to North Carolina as an example of what he feels is their advantage on the ground in key states.
"We've had staff on the ground there since June 2019," Stepien said. "The staff has grown to over 100, which is double [the] 2016 staff. And they've been hard at work, shockingly, registering voters, and we see the results of that. They just made their 3 millionth voter contact."
"Joe Biden hired his state director last month [in North Carolina]. Big advantage: us on the ground," he added.
Stepien, who took over for longtime Trump campaign manager Brad Parscale just weeks ago, also said the campaign was bullish on flipping Minnesota. The Biden campaign only recently hired a handful of staffers in the state, compared to Trump Victory, which has had a physical presence in Minnesota since the 2016 election. Trump only lost the state by 1.5 percentage points.
However, recent polling suggested the president will still have a tough time turning Minnesota red. A recent Fox News poll showed Biden is leading in the state by 13 points: 51% to 38%.
The Biden campaign maintains that its hesitance in putting staffers and volunteers back on the ground amid the pandemic is rooted in science and the safety of their team.
"The Biden campaign is following the science and campaigning safely, yet very effectively," TJ Ducklo, the Biden campaign's national press secretary, said. "Our field teams and volunteers are talking to thousands of voters, holding hundreds of virtual events and continuing to build the broad, diverse coalition that is going to send Joe Biden to the White House."
The Trump campaign has also continued to put up massive digital numbers even as the Biden campaign remains fully virtual. The last 10 virtual campaign events have averaged over 1 million views on Facebook alone.
And on the ground, Trump Victory, the joint field operation between the RNC and Trump campaign, has hired more than 1,500 field staffers this cycle already and has activated over 1.6 million volunteers, according to the RNC.
Some Democrats who recognize the complicated reality of campaigning amid a pandemic still feel Biden remaining on the sidelines while the president's campaign pounds the pavement unchallenged could spell serious trouble in November.
"We're going to lose Election Day," said Wilnelia Rivera, who was Rep. Ayanna Pressley's chief campaign strategist for her successful 2018 race in Massachusetts. "If the Biden campaign continues down this track of running a traditional, candidate-driven, TV-spending campaign, it's not going to be enough."
"By now, I expected it to see a surrogate campaign of many aligned Democrats issuing a coordinated message of what it is that we need right now: to not just win in November, but to put our country back on track," said Rivera, a contributor to the book "Turnout: Mobilizing Voters in an Emergency."
Rivera said she's not suggesting Democrats put volunteers or staff in "harm's way" amid the pandemic, but said they need to start realizing that Republicans "are not going to play this election fair" -- campaigning as if the country was not in the middle of a health crisis.
Other veteran Democratic staffers who worked on campaigns during the 2020 primary, who spoke on the condition of anonymity because they didn't want to criticize the presumptive nominee's campaign, told ABC News they have been stunned at how long it's taken the Biden campaign to start to put staffers in key states. "I've never seen a general election campaign this understaffed in battleground states this close to Election Day," one source told ABC News.
David Broockman, a professor of political science at the University of California, Berkeley, told ABC News he doesn't expect Biden to be significantly impacted by staying on the sidelines due to the pandemic, arguing that canvassing only reaches "a relatively small proportion of Americans."
"As a result, I doubt the Biden campaign's decision will prove that determinative, since even if they had canvassed I doubt it would be at a scale that would likely tip the balance," Broockman said.
"I suspect much more energy will be put into phone-based persuasion approaches as a substitute for in-person canvassing," he added, the latter of which he said can backfire if executed poorly. "I suspect it will take some creativity to inspire the same esprit de corps among volunteers to make these calls, but if the campaigns can keep volunteer motivation high, I suspect they can have a relatively large impact with phone calls as well."
Greta Carnes, the national organizer for former South Bend, Indiana, Mayor Pete Buttigieg's 2020 presidential campaign, said that while on-the-ground campaigning is important, Democrats are doing the right thing moving forward with caution and not putting staff and voters at risk.
"The biggest reason why we're choosing not to canvass is because there is not an ethical way to canvass during a pandemic, there's just not," Carnes said.
"It's one thing to know that you're putting your volunteers at risk, but it's totally another to have them go to doors and you have no idea what the situation of people at those doors is," she added. "You have no idea if they have a kid who's got cancer. You've got no idea if they're immunocompromised. There just, point blank, is no ethical way to approach canvassing at scale in a year like this."
As Trump continues to campaign during the pandemic, his staff has been impacted, with at least eight members of the advance team who worked on his June 20 return rally in Tulsa testing positive for coronavirus.