At 12:01 p.m. ET on Friday, Donald Trump will begin one of the most complex takeover operations in the world.
The transfer of control over the sprawling U.S. government from one administration to the next is a hallmark of American democracy. It's also a daunting logistical challenge that requires months of planning and complex choreography on inauguration day, when Mr. Trump will be sworn in as the 45th president of the United States and Barack Obama will leave office.
For weeks, small "landing" teams from Mr. Trump's transition effort have spent time at government departments and agencies to get a grasp on the bureaucracy they are about to inherit. And members of Mr. Obama's cabinet have sat next to their would-be replacements in simulated crisis situations, to prepare incoming officials for what they soon will face.
But Jan. 20 is when everything actually changes. At the White House, the moving process unfolds over the course of about six hours. Mr. Trump and his wife Melania will arrive at 10:30 a.m. for coffee with Mr. Obama and his wife Michelle. Then they all travel to Capitol Hill for the swearing-in ceremony at noon and a luncheon, which is followed by a parade on Pennsylvania Avenue. In the meantime, the staff at the White House hurries to ready the residence for its new occupants.
For many of Mr. Trump's senior White House staff, Friday afternoon will be the first time they enter the place where they will spend most of their waking hours.
Chris Lu, who was the primary liaison between the president and the cabinet departments and agencies during Mr. Obama's first term, remembers boarding a bus with other senior staff immediately after Mr. Obama was sworn in. The bus travelled down the empty parade route to the White House, where the staff members were each given a government-issue BlackBerry and shown to their offices in the West Wing.
Mr. Lu's office had a chair and a phone and not much else (his desk and computer would arrive the following day). He called his mother to mark the occasion. Not knowing exactly what to do, he started walking the hallways and greeting colleagues, who joined him to explore their new digs. The Secret Service let them take a peek at the Oval Office and wander through iconic rooms on the ground floor of the White House.
"Functionally, there's not much you can do because most of the federal government is closed that day," Mr. Lu said. The next morning, the senior staff met at 8:30 for the first of its daily meetings. "It went from zero to 60 very quickly."
Because new administrations must staff up in rapid fashion, the hiring process is compressed. Kenneth Baer, a former official in the White House Office of Management and Budget under Mr. Obama, recalls being offered his job on Jan. 12, 2009, and told to start the day after the inauguration, nine days later. He arrived early that morning – on little sleep following postinauguration parties – to join an administration confronting a full-blown economic crisis. "It was a really amazing moment," Mr. Baer said. "It took a couple of days to sink in how ambitious the goals were and how dire the situation was."
The abruptness of the transition at midday on inauguration day can pose challenges for certain functions of government. Mr. Obama's appointees have submitted resignation letters effective that day (civil servants occupy the appointees' roles in a temporary capacity until Mr. Trump's picks are approved by the U.S. Senate). While they are technically on the job until Friday, hundreds of officials are already packing up their offices and exiting the scene this week, as are junior staff in the West Wing.
Sometimes circumstances require flexibility. On inauguration day in 2009, incoming and outgoing administration officials grappled together with reports of a security threat, notes Martha Kumar, a professor at Towson University and director of the White House Transition Project. That morning, while Mr. Obama and his wife were having coffee with outgoing President George W. Bush and his wife Laura, the cabinet secretaries who deal with homeland security and their new counterparts were meeting in the White House Situation Room to consider the threat, Prof. Kumar said.
A recent law made it mandatory for outgoing administrations to hold a "tabletop" exercise with their incoming counterparts. On Friday afternoon last week, Obama administration officials discussed various crisis scenarios – terrorism, natural disasters, cyber attacks – with their likely replacements for about three hours at the Eisenhower Executive Office Building next to the White House. Those in attendance included Rex Tillerson, Mr. Trump's nominee for secretary of state, Steve Mnuchin, his pick for treasury secretary and James Mattis, Mr. Trump's choice for secretary of defense.
Mr. Obama has made it clear that he expects his staff to extend every courtesy to the incoming administration, just as his predecessor instructed his staff to do. "The Bush people could not have been kinder and more gracious to us," said Mr. Lu, the former White House official. That attitude helped produce what is considered a successful hand off.
The atmosphere isn't always so harmonious: When Mr. Bush took office in 2001, there were reports of pranks by President Bill Clinton's outgoing staff, such as removing the "w" keys – the new president's middle initial – from White House keyboards.
It's too soon to say whether Mr. Trump will be credited with an effective transition process, said David Eagles, director of the Center for Presidential Transition at the Partnership for Public Service in Washington. The scope of the task is vast, he notes: there are roughly 4,000 political appointees in the U.S. government, more than 1,000 of which require approval from the Senate.
The race against time will only intensify after Friday. "You've got to get your team on the field and you've got to get them prepared," Mr. Eagles said.