John J. Kim/Chicago Tribune/Tribune News Service via Getty ImagesBy JOHNNY VERHOVEK and MOLLY NAGLE, ABC NEWS

(NEW YORK) -- Former Vice President Joe Biden has approved a series of new hires that will significantly expand his presidential campaign and could begin to quell concerns among a growing chorus of Democrats that are anxious for his team to scale up ahead of the general election fight with President Donald Trump.

The staffing includes new senior advisers with a focus on the virtual side of campaigning, all coming from former competitors-turned-endorsers' campaigns.

Caitlin Mitchell, the former chief managing officer of Warren for President, is joining the campaign as a senior adviser for digital, and will advise on digital strategy and help the campaign as they quickly scale up their in-house teams, according to a Biden campaign aide.

Rob Flaherty, the Biden campaign's digital director, confirmed Friday that the campaign will be doubling the size of its digital team, which stood at roughly 25 people throughout the primary, a move that comes amid concerns over the reach and manpower possessed by Trump's well-stocked reelection effort.

"Biden Team digital is scaling.....fast. Really fast. Like we're going to double the team in a matter of weeks….and then keep on growing," Flaherty wrote in a lengthy thread on Twitter early Friday evening.

Former creative director for Beto O'Rourke's campaign, Robyn Kanner, will join Biden's campaign as senior creative adviser, leading the design, branding and web efforts of the campaign, according to the aide.

Andrew Gauthier will also join as a video director for Biden, after serving as the digital content director at Kamala Harris' campaign, and as an executive producer of BuzzFeed Video.

News of the campaign's expansion was first reported by The Washington Post on Friday.

The hires come as the the former vice president's team has been faced with a steadily increasing drumbeat of criticism in recent weeks from anxious Democrats that the candidate and his campaign are not implementing both the organizational and strategic changes they say are needed to unseat a well-funded and seemingly omnipresent incumbent on a political battlefield upended by a global pandemic.

While the hires may satisfy some of the concerns, this week saw two of the masterminds behind Barack Obama's successful bids for the White House, and the woman behind the unlikely rise of Pete Buttigieg from unknown mayor to presidential contender, pen op-eds in The New York Times urging the Biden campaign to recalculate its strategy -- a notable public step from Democratic politicos who certainly have the ability to privately express their concerns.

"Adjusting to the new political realities is imperative for Mr. Biden, who ran his first campaign for office a half-century ago. In order to break through and be heard, he will have to up the tempo of his campaign, fully utilize his army of powerful surrogates and embrace a new suite of virtual, data-driven tools and creative tactics," David Axelrod, the senior strategist for Obama's campaigns in 2008 and 2012, and David Plouffe, Obama's campaign manager in 2008, wrote in a joint op-ed in the Times on Monday.

"Online speeches from his basement won't cut it," Axelrod and Plouffe warned.

Lis Smith, a former senior adviser for Buttigeig's 2020 campaign, argued that while stuck in his basement, Biden should become "omnipresent," and the campaign could be expanding their reach into the demographics they'll need come November.

"His campaign should analyze the primary media consumption habits of the voters they need to put together for a winning coalition. For voters under the age of 40, it's on mobile screens and social media; for black voters, local TV news; for Latino voters, Spanish-language TV and radio news outlets like Univision, Telemundo and La Mega, along with English-language local media in metro areas with large Latino populations," Smith, who also worked on Obama's 2012 reelection campaign, suggested.

Even longtime conservative strategist and top George W. Bush lieutenant Karl Rove felt compelled to offer the presumptive Democratic nominee some advice, writing a Wall Street Journal op-ed on Thursday positing his own theory on how Biden should craft his message in his battle with Trump.

The outreach, though frank, is coming as the Democratic Party settled on a presumptive nominee earlier than any cycle since 2004, and at a time when traditional campaigning, defined by the whirr of constant travel and activity, is on pause.

"It is true you get a lot of incoming, but now is a fine time for that kind of engagement," Amanda Renteria, who served as Hillary Clinton's 2016 national political director, told ABC News about the influx of advice.

"This is what you do as you step up, you start to listen to those stakeholders," Renteria added. "This is the first time we've had a clear candidate this early on. ... I'm not surprised to see it. I also think a good campaign will go, 'Great, let me bring that in. Let's talk about, where do you think we should be?' And I think that's always helpful, especially as the party's coming together."

Some of the advice -- particularly the idea of connecting with media outlets on the local and national level and social media profiles that reach different audiences -- has already been undertaken by the campaign, though without regularity.

The Biden campaign declined to comment on the advice offered in the op-eds when asked by ABC News.

The concerns articulated by those top Democrats (and Republican) were in no way allayed this week when Biden's first attempt at localized virtual campaigning, a "rally" in Tampa, Florida, on Thursday night meant to mimic the look and feel of an in-person event, was marred by debilitating technical issues.

Audio glitches, awkward stares of guests unsure if they should begin speaking and a blank screen for five minutes at one point, put another damper on what was supposed to be the next phase of the Biden team's attempt to adapt to the virtual campaign trail, and again highlighted the digital deficit it still faces with the Trump campaign now less than six months from Election Day.

Biden's campaign enters the now mostly digital general election at a stark disadvantage online. Trump has over 27 million likes on Facebook, Biden has 1.8 million. Trump's YouTube page has over 28 millions views with nearly 400,000 subscribers, while Biden's has 8.3 million views with 50,000 subscribers. On Twitter, Trump has 79.5 million followers, and Biden has just 5.3 million.

Biden has tried to expand beyond the reach of his own channel, delivering an economic message that appeared to highlight a focus of his general election message, taking aim at Trump on his "corrupt" economic agenda on the youth-targeted NowThisNews, which lacked the technical issues of Biden's Florida remarks.

The platform reaches 60% of Americans in their 20s and racks up 2 billion views each month, according to a release from the mobile news site promoting Biden's Friday speech.

Renteria praised the campaign's "experimentation," but stressed the importance of not just trying new mediums to get Biden's message out, but learning from the "feedback loops," generated through the events themselves that shed light on what works and what doesn't on certain platforms.

"They have to keep discovering new places to be. ... But it's not just whether you hop on this Instagram, or this Facebook Live, or this channel that usually politicians aren't on, it's as much about the content you're learning that connects with those places," Renteria said.

Some digital strategists argue that it's not about winning across the internet against Trump, but focusing the campaign's digital fire power where it matters.

"I think we're having the wrong conversation. We keep asking ourselves if Biden's digital operation is good. But the real question is, 'Is Biden's digital good in the six states that will decide this election?'" Stefan Smith, the former online engagement director for Buttigieg's 2020 campaign, told ABC News.

"I don't care if Joe Biden goes viral in New York. I would hope that we already have their votes. I care about whether Joe Biden is going viral in the closed Facebook groups of suburban white women who live in Wisconsin. That's the question," Smith said.

Biden's state-focused virtual strategy is expected to continue over the next several weeks for the former vice president and his high-level surrogates, like his wife Jill Biden, who "spent the day" in another key battleground state, Michigan. Biden beamed into three events Wednesday, acknowledging each time the havoc that the COVID-19 crisis has wrought on the campaign trail.

"We've had to figure out, you know, what it means to run a presidential campaign when you can't fly or have a bus tour or even visit people's homes," Biden told a roundtable featuring nurses from the Detroit and Ann Arbor areas from her Wilmington, Delaware, home's now-recognizable basement studio.

The Michigan visit also featured an event focused on organizing amid COVID-19, offering guidance for volunteers to spread the campaign's message in a way that is "tonally appropriate."

"We really need to be mindful of the tone that we're setting right now in our approach," Gabriella Cascone, national training director for the Biden campaign, told organizers.

"We're following the vice president's lead, and being really mindful of the crisis that we're in right now or looking for opportunities to bring supporters together are always acknowledging the realities and the stressful situations of COVID-19," Cascone said.

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