Thick packets have been delivered regularly to President-elect Joe Biden’s Wilmington, Del., home, providing meticulous details on each potential Cabinet member’s strengths, weaknesses and possible areas of conflict. Biden has been conducting virtual interviews with final candidates, focusing on their values and life stories nearly as much as their approach to the departments they would lead.

He has made Vice President-elect Kamala D. Harris perhaps his closest partner in the ­Cabinet-selection effort; she has interviewed each candidate separately and traded notes with Biden afterward in what people close to the transition say has been an important step in deepening their working relationship.

Biden’s transition — which began months before the election results were known — is providing the first portrait, if one largely conducted behind the scenes, of his style as a manager and decision-maker in chief.

From the outside, advocates, groups and members of Congress can find his process cryptic and unpredictable as they attempt to discern which directions Biden and his small core of advisers are leaning, only to find out that he has abruptly switched course. Some nominations have been handled much more quickly than expected, while other decisions have lingered, creating some frustration even among allies. Proponents of demographic and ideological diversity have complained that he has vested too much power in more-moderate White officials like himself.

But Biden, in what was a defining feature of his campaign, has largely shrugged off the criticism, confident in his own approach to what he sees as a gut-check decision-making process. Lately, he has become more animated in defending some of the choices that his internal deliberations have yielded, urging those on the outside to take his full Cabinet into consideration.

“This Cabinet will be the most representative of any Cabinet in American history,” Biden said Wednesday while introducing Pete Buttigieg, who would be the first openly gay Cabinet secretary, as his nominee to run
the Transportation Department. “We’ll have a Cabinet of barrier breakers, a Cabinet of firsts.”

President-elect Joe Biden has chosen Pete Buttigieg, a former rival for the Democratic presidential nomination, to lead the U.S. Transportation Department. (Reuters)

The formation of the Biden Cabinet began much earlier and has been far more comprehensively planned than previously known, according to multiple people close to the effort who spoke on the condition of anonymity to discuss internal deliberations.

Biden instructed transition officials months ago that he wanted a range of options for jobs available in his administration. By Election Day, the transition had built a database of 9,000 potential administration hires. Some 2,500 had already been vetted — half of whom were people of color and more than half of whom were women. That database now has more than 45,000 entries.

Inside the transition, officials say they have tried to exceed the Rooney Rule — the NFL requirement that teams interview at least one minority candidate for every head coaching and high-level job — so that more would have an opportunity to be considered, according to several people involved with the transition. That has not stopped criticism of Biden’s eventual selections, particularly for the highest-profile roles.

Biden prefers to work from paper: His transition team has so farsent him more than 130 detailed background memos on the candidates.

“The Biden transition team is the most-organized, best-resourced and most-effective transition team ever,” said David Marchick, director of the nonpartisan Center for Presidential Transition, who has worked for months with Trump and Biden transition officials. “Future transition teams, Republican and Democratic, will be studying their model. They’re just wickedly organized.”

Four years ago, President Trump’s transition provided an early indication of how Trump would conduct his presidency. Potential nominees were paraded into Trump Tower in New York or to his golf course in Bedminster, N.J., to shake hands before television cameras. Trump and Mitt Romney, then a possible secretary of state, dined on frog legs at Jean-Georges in Manhattan.

Chris Christie, then governor of New Jersey, had set up a vetting process, a detailed schedule and 30 volumes of transition documents in the months before the election, only to get pushed out along with his plans just days after Trump’s victory. In many cases, Trump, a relative political newcomer, settled on nominees with whom he had little relationship but whom he thought looked the part.

In part because of health protocols, but also by design, Biden’s opening efforts to form his administration could not be more different.

During his interactions with potential Cabinet members, which have been mostly virtual until the formal announcements, he is rarely confrontational, and more often casually breaks the ice. During a video call with homeland security candidate Alejandro Mayorkas, the former Obama administration official stumbled over how to address the president-elect.

“Just call me Joe,” Biden eventually said, by Mayorkas’s account.

While Harris’s role is still undefined and her imprint on the choices of the nominees is so far unapparent, she has been involved in almost every discussion as Biden makes decisions on his administration, according to people involved in the process.

“She is the first and last in the room. He is asking her input and her feedback,” said a person involved in the transition. “That’s the partnership Biden had with [President Barack] Obama, and as Harris wanted with Biden. . . . He wants her feedback.”

The discussions about Cabinet picks and other high-profile posts are kept to a very small circle, with Harris and Biden joined by incoming White House chief of staff Ron Klain and just a handful of others. The mood veers from light banter — with joking laments from Biden about how he fractured his foot playing with one of his dogs — to the severity of the economic and health crises his administration will confront.

“He gave us all the following advice: These are tough jobs, make sure you take care of yourself and your family,” Mayorkas said.

Former senator Chris Dodd (D-Conn.), who helped lead Biden’s similar vice-presidential search process, said Biden’s management style is one of “a collaborator.”

“He likes to talk things out,” Dodd said. “He’s not averseat all to people expressing alternative views. It’s a very healthy approach. He’s not insular in any way.”

While Biden has a soft spot for hiring people he knows and has long worked with, he likes to have a wide range of options.

“With the vice-presidential selection process, I had assumed we’d narrow candidates down to two or three people,” Dodd said. “Joe wanted to see a lot. He really wanted more of an opportunity to meet with and talk to folks. It was like six, seven, eight people. I was sort of surprised.”

The transition team has examined each agency and looked at how it has been run historically and which model of leadership was most successful — a chief executive, or a budget expert, or someone who looked through a regulatory lens. Candidates were judged by how best they fit the model the transition team decided on for each job, and those options were presented to the president-elect.

In most of his picks, Biden has valued expertise — not necessarily in particular subject areas but in crisis management. In his view, his administration is inheriting a multipronged crisis, and a government workforce that has spent four years being disparaged and downplayed. That is why many of his appointments have extensive government service, those close to the decision-making say.

That instinct, however, has led to some unusual picks that have baffled outside groups that closely follow each department. Xavier Becerra, the California attorney general, has little background running a health-care agency but has been nominated as secretary of health and human services. Denis McDonough, a former chief of staff to Obama, was chosen to lead the Department of Veterans Affairs despite never having served in uniform.

In both cases, the perception of their general abilities overrode outside concerns about their expertise in those specific areas.

Biden has always been one who stews over difficult decisions, letting them linger and growing agitated with those who try to rush him. Deciding whether to run for president, including for the most recent of his three campaigns, was a process that stretched later than advisers wanted, as he ruminated over the possibilities in front of him before making a final decision.

His advisers describe a decision-making and hiring approach that resembles the playing of an accordion, starting wide and then narrowing — and then, sometimes suddenly, expanding once more.

Becerra was initially not a top candidate for HHS, but then suddenly was filling out paperwork to be vetted late in the process. Retired Army Gen. Lloyd J. Austin III was not considered a top pick for secretary of defense until shortly before Biden announced his nomination, causing his team to scramble to line up support and catching key Democratic senators off guard.

The quest for an attorney general nominee appeared to have narrowed in recent days, but advisers then began floating the name of New York Gov. Andrew M. Cuomo (D), according to two people close to the process, even though he has repeatedly denied interest in t he job and Biden has been primarily focused on a trio of other candidates.

Biden views his decision-making as taking into account broad amounts of information and then relying on his gut — and what he considers to be his forte, homing in on what is politically possible.

“I measure what happens, how the leaders that I’ve served with based on . . . whether their judgment about what to do comes from their gut or their head,” he said earlier this year during a virtual roundtable to discuss rural issues in Wisconsin.

“I trust people who start with their gut,” he added. “And they have had a head bright enough to know what to do about that gut feeling. People who arrive at it purely from intellectual standpoint, they’re not always ones that can be counted on to stay through at the very end when it gets really tough. . . . It starts here in the gut, and it moves to the head.”

Those who have worked with Biden say he trusts his instincts even when they run counter to the advice he is given.

“He’ll be the first to tell you, ‘I have better political instincts than all of you,’ ” said one adviser. “He wants the recommendations. He will hear varied perspectives, and he wants people to present their case. But at the end of the day he listens to his gut. If everybody is like, ‘Sir, we have to go right,’ and he says, ‘My gut says we have to go left,’ he’s going to give his gut a lot of weight.”

Harris and Biden, who receive the same packets of information on potential appointees, ask numerous follow-up questions in their interviews, at times evaluating two candidates against each other or trying to determine whether a substantive difference between Biden’s position and those of the potential nominees is a disqualifier.

Becerra, for example, has long been a proponent of Medicare-for-all, the health-care plan Biden campaigned against, instead favoring expansion of Obamacare. But those differences were not deemed a big enough problem to thwart his nomination.

Most of Biden’s choices so far are aligned with his views — and, in many cases, have helped shape his views over the decades. His nominee for secretary of state, Tony Blinken, is one of Biden’s longest-serving foreign policy advisers, helping craft lines that Biden still quotes to this day. Klain, the chief of staff, was Biden’s chief of staff when he was vice president.

Biden’s virtual sessions have at times been folksy and conversational, much as he appears in public. If a dog barks during a presentation, he defuses the tension by laughing about it. If a staff member’s children walk into the screen, he’ll engage them in conversation.

“Biden understands it’s so much bigger than him,” said Rep. Cedric L. Richmond (D-La.), whom Biden has named as senior adviser and director of the White House Office of Public Engagement. “He’s not caught up on title and he’s not caught up on what people call him in the interview. . . . Trump is erratic and it’s all about Trump. If you do anything to take attention away from him, he acts like a child. Biden does not seek or crave attention.”

But, publicly and privately, he does like to talk.

“When I first sat down with Joe Biden, it was like I had known this man for 10 years. I didn’t know him at all,” said one person who has interviewed with Biden in the past. “But by the end, he’s offering his cellphone number and making jokes and talking about family. That’s just who Joe Biden is.”