WASHINGTON, D.C. — President Donald Trump’s troubled search for his third chief of staff illustrates the sharp decline in power and desirability of a job that long was regarded as a plum in politics —either the capstone for a prestigious career or a launching point for one.

But Trump has, as with most everything he touches, radically changed that calculus.

The disruptive president has shown repeatedly that he prefers to operate as his own chief of staff, rebuffing attempts to streamline White House communications and decision-making as he goes his own way. That makes filling the post especially difficult.

Both Reince Priebus, Trump’s first chief of staff, and his replacement, John F. Kelly, were mauled by the experience, battered and belittled as a frequent target of Trump’s ire.

The position, first created under President Harry S. Truman, has been the “most important job” in any West Wing over the last half a century, said Kathryn Dunn Tenpas, a researcher at the nonpartisan Brookings Institution who studies White House staffing issues and Trump’s record-breaking staff turnover.

Trump, she said, has rendered the chief of staff’s job less powerful —and less attractive.

“Two individuals have assumed that role,” she said. “Both have been humiliated publicly. The position under Trump will never be what it was with other administrations, given his impulsiveness and inability to delegate to others.”

A former White House official called the job under Trump “pointless, an exercise in futility.”

“No rational qualified person would jeopardize their reputation” with special counsel Robert S. Mueller III’s investigation “heating up. And you just can’t manage the guy,” said the official, who requested anonymity to avoid upsetting his current employer and existing relationships in the administration.

Trump’s top pick to replace Kelly, Nick Ayers, unexpectedly withdrew his name over the weekend and instead will leave the White House to return to his home in Georgia and work on Trump’s re-election campaign.

One official said Ayers was bothered by the increasing threat to Trump from the Russia investigation and a related federal probe in Manhattan, which last week said Trump —identified only as Individual 1 —had directed an illegal scheme to pay hush money during the 2016 election.

“Ayers didn’t want to be chief of staff to Individual 1 and get walked all over once Kelly left,” the official said.

Ayers, who is chief of staff to Vice President Mike Pence, would only agree to take the more senior job for a few months, and Trump wanted him to remain the full two years until the next election, according to a White House official who requested anonymity to discuss the sensitive issue.

Normally, an up-and-coming political operative like Ayers, 36, would have jumped at the chance to take the career-making job. His reluctance demonstrates the perils of working in Trump’s White House.

Ayers’ appointment appeared so certain that the press staff had prepared an official release in the middle of last week, according to one of the officials.

Trump then announced Saturday that Kelly would leave by the end of the year. Normally, such an announcement would only be made if a successor were certain.

People close to Trump and the White House floated a variety of potential candidates on Monday.

They included Rep. Mark Meadows, a North Carolina GOP firebrand who has been close to Trump; Steven T. Mnuchin, Trump’s loyal Treasury secretary; Mick Mulvaney, Trump’s budget chief who also did fill-in work running the federal consumer agency; and Chris Christie, the former New Jersey governor who has long sought a position in the Trump administration.

Kelly was hired in July 2017 to impose order and structure after Priebus proved unable to tame the chaotic information flow coming to the president or restrict the impromptu visits of staffers from across the administration hierarchy.

But Kelly also showed he had little ability to tell Trump hard truths, monitor his late-night phone calls to informal outside advisers who had their own agendas, or to rein in explosive tweets and impulsive orders.

White House officials have largely given up on finding someone who could fill the traditional role as Oval Office gatekeeper and enforcer in the mold of James A. Baker III, who served under President George H.W. Bush, or Leon E. Panetta, who filled a similar role for President Bill Clinton.

The chief of staff traditionally serves as the president’s top deputy, a figure who helps the president fulfill his agenda. Trump’s next chief of staff will also work on his 2020 re-election plans.

No one in the White House expects an empowered chief, given Trump’s persistent desire to remain the focal point. One official said the next chief should function as a chief political strategist before correcting herself to say Trump would always be No. 1 and that whoever took the job could be his assistant.

“The president’s always his own chief strategist,” the official said.

Anthony Scaramucci, who lasted 10 days as Trump’s top communications official, knows well the perils of serving Trump. He told CNN that Kelly’s lack of personal respect for Trump hampered his ability in the job.

“I want the next chief of staff to be somebody that really likes the president,” said Scaramucci, whom Kelly quickly fired. It’s not enough, Scaramucci added, to believe: “I’m serving the country, but I don’t really like the president.”

Kelly, like many who work in Trump’s White House, saw his own reputation diminish during his tenure as he defended Trump’s behavior and rhetoric, while the president did little to back him up in public.

Kelly’s replacement will also have to contend with the Mueller probe and other investigations, which continue to roil Trump and those around him.

But even those on Trump’s shortlist may not last long. Christie has talked to people in Trump’s orbit and said in essence, “If the president wants to call me, he can call me.”

But others in the administration doubt that Trump’s son-in-law, Jared Kushner, whose office is right next to the chief of staff’s, would allow it. Christie prosecuted Kushner’s father, Charles, in a case that resulted in guilty pleas and prison time for campaign finance violations, tax evasion and witness tampering.

One lobbyist close to Trump insisted the president will find a good candidate and was not discouraged by Ayers’ withdrawal. He said many in the administration were opposed to Ayers, whose youth and ambition have drawn some criticism.

“So the timing may have been a way out,” said the lobbyist.

But the impression that the job is no longer desirable is only likely to exacerbate Trump’s recruitment troubles.

“Recruitment for White House jobs gets more difficult over time, once the post-election glow fades and the first-stringers leave,” said Tenpas, the Brookings scholar. “With Trump, that whole process is magnified tenfold, especially with the chief of staff job because of what’s happened already.

“Why would someone take a job like that when they’ve seen two other people fail?” she said.