In the course of the transition, in what appears to be like in hindsight like a preview of the presidency, one Trump aide acquired the concept of printing out the detailed guidelines of Mr. Obama’s marketing campaign guarantees from the official White Home web site to repurpose as a sort of hit checklist, in accordance with two individuals acquainted with the trouble.

“That is private for Trump; it’s all about President Obama and demolishing his legacy. It’s his obsession,” mentioned Omarosa Manigault Newman, an “Apprentice” veteran and, till her abrupt departure, one of many few black officers in Mr. Trump’s West Wing. “President Obama won’t be able to relaxation so long as Trump is respiration.”

When the 2 males met for a stilted postelection sit-down in November 2016, the president-elect was well mannered, so Mr. Obama took the chance to advise him in opposition to going scorched-earth on Obamacare. “Look, you possibly can take my identify off of it; I don’t care,” he mentioned, in accordance with aides.

Mr. Trump nodded noncommittally.

Because the transition dragged on, Mr. Obama grew to become more and more uneasy at what he noticed because the breezy indifference of the brand new president and his inexperienced group. Lots of them ignored the briefing binders his employees had painstakingly produced at his route, former Obama aides recalled, and as a substitute of specializing in coverage or the workings of the West Wing, they inquired concerning the high quality of tacos within the basement mess or the place to discover a good condominium.

As for Mr. Trump, he had “no thought what he’s doing,” Mr. Obama advised an aide after their Oval Workplace encounter.

Jared Kushner, Mr. Trump’s son-in-law and shut adviser, made an equally indelible impression. Throughout a tour of the constructing he abruptly inquired, “So what number of of those persons are sticking round?”

The reply was none, his escort replied. (West Wing officers serve on the president’s pleasure, as Mr. Trump would amply illustrate within the coming months.)