At the National Security Council, Trump officials were reluctant to share information about who was even on the staff, and at the Department of Defense, requests for information were either ignored or only partially answered. At the Office of Management and Budget, the practice of making career officials available for the incoming administration to craft their budget was disregarded, leaving Biden officials frustrated that their budget will likely be delayed. And at the Office of the United States Trade Representative, the lack of interest in assisting the Biden transition was stated plainly.

“Transition is not a priority for USTR,” Robert Lighthizer’s chief of staff told a Biden official, according to a person briefed on the conversation…

The obstacles to the Biden transition’s work spanned across the government and ranged in severity. Some Trump staffers tried to be helpful, Biden officials said, but President Donald Trump’s refusal to concede to Biden stymied the handoff from the top. The feeling on Biden’s team, as they turn to governing after the exhilaration of victory and the frenzy of transition planning, is something akin to peering into a dark abyss: They don’t yet know what lurks out of view.

And as Biden and his staff move into the White House and agencies on Wednesday, administration officials recognize that some of their priorities will inevitably be sidelined by the need to fix messes from the outgoing administration that they aren’t even aware of yet.