The departure of Donald Trump’s communications director, Michael Dubke, was not unexpected. With the White House under the F.B.I.’s magnifying glass, Trump has been said to be considering a wide-ranging staff shakeup after he blamed his in-house press shop for failing to contain the fallout from his abrupt decision to fire James Comey, and Dubke was a fitting first casualty of the coming purge. But replacing the embattled communications director could prove to be a difficult task.

While White House jobs are typically among the country’s most coveted and respected positions, the Trump administration is reportedly struggling to fill key positions throughout the government as top-tier talent keeps its distance from the Justice Department investigation into Trump’s campaign ties to Russia. Current staffers have already been asked to preserve materials that could be relevant to the ongoing probe, and aides are reportedly bracing for big attorney bills as the first wave of subpoenas and grand jury summons begins to flow. (A White House spokeswoman told Politico that the Russia investigation has had no impact on hiring, and the president is recruiting individuals “of the highest quality.”)

“It’s an additional factor that makes what was an already complicated process of staffing the government even harder,” Max Stier, who has advised the Trump transition on hiring, told Politico. Of the 559 government appointments that require Senate confirmation, the Trump administration has only named 117 nominees, according to Stier’s nonpartisan Partnership for Public Service. And with a growing number of top Trump staffers coming under scrutiny in the parallel Russia investigations, the talent pool from which the White House can pull is drying up. The New York Times reported that four potential Dubke replacements declined to be considered for the position. Similarly, a lawyer who represents potential government appointees told Politico that three clients are no longer interested in working under Trump. “There’s no doubt in my mind that people are being very cautious, to put it mildly,” the lawyer told the outlet. “You’re going to have a situation where they’re going to have trouble getting A-list or even B-list people to sign up.”

Perhaps the heaviest lift for the White House will be filling Comey’s former role after the former F.B.I. director’s tumultuous and unexpected ouster. Already, Senator John Cornyn, Congressman Trey Gowdy, and former Senator Joe Lieberman have taken themselves out of consideration for the position. And while the administration has pushed back on the narrative that it is struggling to find people willing to fill the hundreds of vacant positions scattered throughout the government, one White House official conceded to Politico, “It’s not so easy to find an F.B.I. director in the Trump administration.”

Trump’s management style has also emerged as a potential factor that could ward off top talent. Despite his expectation of unflinching loyalty from his subordinates, the president is known for belittling even his top staffers and chief allies. Trump’s infamous snubs range from depriving Press Secretary Sean Spicer, a Catholic, of meeting the Pope, to joking about firing United Nations Ambassador Nikki Haley, to calling House Speaker Paul Ryan a “Boy Scout.” Aides who defend the president in public are often contradicted, or thrown under the bus, by their boss just hours later. And the constant public humiliations of Reince Priebus are a cautionary tale for would-be employees that even the president’s chief of staff is not above mockery and derision.