Mr. Abrams's experience has become a case study in the challenges Mr. Trump still faces in filling top positions a month into his presidency. Mr. Trump remains fixated on the campaign as he applies a loyalty test to some prospective officials. For their part, many Republicans reacted to what happened to Mr. Abrams with dismay, leaving them increasingly leery about joining an administration that cannot get past the past.

As Mr. Trump brings candidates for national security adviser to meet with him in Florida this weekend, he presides over a government where the upper echelons remain sparsely populated. Six of the 15 statutory cabinet secretaries are still awaiting Senate confirmation as Democrats nearly uniformly oppose almost all of the president's choices. Even some of the cabinet secretaries who are in place may feel they are home alone.

It is not just Secretary of State Rex W. Tillerson who has no deputy secretary, much less Trump-appointed under secretaries or assistant secretaries. Neither do the heads of the Treasury Department, the Education Department or any of the other cabinet departments. Only three of 15 nominees have been named for deputy secretary positions. Defense Secretary Jim Mattis has a deputy only because he kept the one left over from President Barack Obama's administration.

That does not even begin to cover the rest of the more than 4,000 appointments that a president typically makes. In some cases, the Trump administration is even going in reverse. A senior political appointee at the housing department, who had already started the job, was fired this past week and marched out of the building when someone discovered his previous statements critical of Mr. Trump.

The president's top Latin America official at the National Security Council was likewise fired after just weeks on the job for complaining about internal dysfunction at an off-the-record discussion at a Washington research organization, according to officials, who confirmed a Politico report. The State Department has laid off six top career officials in recent days, apparently out of questions about their loyalty to Mr. Trump.