Nothing is more important to President Trump than loyalty — to him.

In business and in politics, he has demanded it from the people closest to him. Some employees who abandoned him were never welcomed back. Politicians who did not defend him after the most politically damaging moments of the 2016 campaign are still suspect in his eyes. And after six months as president, Trump is still known to publicly jab at people who did not support his presidential bid.

But as Attorney General Jeff Sessions learned this week, the loyalty Trump expects isn’t always reciprocated.

Sessions was one of Trump’s earliest supporters in Congress and one of the intellectual god­fathers of the nationalist movement that propelled his candidacy. Sessions lent his support, and even his closest aides, to boosting Trump’s core campaign promises on immigration and terrorism. At a time when Trump had no allies in the Senate, Sessions voiced support for Trump’s “movement.”

But the attorney general’s decision in March to recuse himself from the investigation of Russian interference in last year’s election and possible collusion between Moscow and the Trump campaign seems to have made that history irrelevant.

(Taylor Turner/The Washington Post)

Trump unleashed his long-simmering fury at Sessions in an interview with the New York Times published Wednesday, calling Sessions’s decision “unfair” and expressing regret about choosing him as attorney general.

“How do you take a job and then recuse yourself?” Trump said. “If he would have recused himself before the job, I would have said, ‘Thanks, Jeff, but I can’t, you know, I’m not going to take you.’ ”

In Trump’s view, the recusal only served to increase the intensity of the Russia investigation, which the president calls a “witch hunt,” by leading to the appointment of a special counsel.

On Thursday morning, as he tried to highlight a successful drug operation during a news conference at the Justice Department, Sessions faced only questions about whether he would step down in the face of Trump’s public criticism.

The episode seems to vividly capture a Trump trait that is familiar to many of his aides, including chief strategist Stephen K. Bannon, White House press secretary Sean Spicer and White House Chief of Staff Reince Priebus — all of whom have at one time fallen out of Trump’s good graces.

In business and in politics, people who do not measure up might be at risk of losing their jobs, no matter how loyal they have been to Trump. Those closest to him have come to accept this as a reality of his leadership style. Some even remain loyal to Trump after being discarded, knowing he may call on them again in the future.

“Here’s the deal: If you’re doing a good job, he’s not going to fire you,” said former aide Sam Nunberg, who was at one time fired by Trump. Nunberg, who began working for Trump in 2011, calls him a “great manager” despite Trump’s decision to sue him for $10 million in 2016 after their falling-out.

President Trump listens as Attorney General Jeff Sessions speaks during a swearing-in ceremony in the Oval Office in February. (Jabin Botsford/The Washington Post)

Nunberg’s experience is not unique. Trump fired Corey Lew­andowski as his campaign manager after Lewandowski was accused of roughing up a female reporter on the campaign trail and Trump’s children grew disenchanted with his stewardship of the election effort. But Lewandowski has remained a vocal surrogate, phone pal and outside adviser to the president.

The White House is dominated by the uncertainty of Trump’s loyalty to and feelings about his aides and Cabinet secretaries. His spokespeople are repeatedly questioned about whether the president still has confidence in his top advisers, even his son-in-law, Jared Kushner. Early in his presidency, Trump surveyed his friends and associates about Priebus’s performance, and rumors that the chief of staff might be replaced have been an ever-present feature of the first six months of the administration.

Bannon, who, like Sessions, helped hone Trump’s ideology during the campaign and entered the White House as one of its most powerful figures, recently found himself flying too close to the sun and risked Trump’s disapproval.

“I like Steve, but you have to remember he was not involved in my campaign until very late,” Trump told a New York Post reporter in April. “I had already beaten all the senators and all the governors, and I didn’t know Steve.

“I’m my own strategist,” the president added.

Like many things about Trump’s foray into politics, his redefinition of loyalty is a striking change from recent presidents.

“It’s different,” remarked Ari Fleischer, who was press secretary for President George W. Bush. “It’s not how they describe personnel management in business school, but it’s also something that I suspect his top people got used to.

“I personally would never fit in an environment like this, but there’s more than one style that can be made to work, even if it makes things harder — and I do think this makes things harder,” he added.

For those in Trump’s orbit, this kind of loyalty has always been in his manual for success.

In “Trump Revealed,” a biography written by Washington Post reporters, a former employee recalled a seminal incident in the early 1990s when the opening week of Trump’s Taj Mahal casino in Atlantic City teetered on the brink of disaster. Trump was eager to look around for blame, promising to fire any employees who contributed to the failure. He even sought to blame the casino’s problems on the staff connected to a Trump deputy who had recently died in a helicopter crash.

Trump has acknowledged that his willingness to prioritize his success and well-being over that of other people close to him is a feature of his leadership style.

In his 2005 book, “Think Like a Billionaire,” Trump compared himself to wealthy business executives such as Apple co-founder Steve Jobs and Turner Broadcasting founder Ted Turner, whom he characterized as “successful in part because they are narcissists who devote their talent with unrelenting focus to achieving their dreams, even if it’s sometimes at the expense of those around them.”

To make the comparison, Trump drew on the work of psycho­analyst Michael Maccoby, who wrote the book “The Productive Narcissist.”

In an interview Thursday, Maccoby said that Trump’s focus on one-way loyalty is common in politics, but it is also common among the narcissistic personalities that Trump identified in “Think Like a Billionaire.”

“The problem is that there’s no mutual loyalty,” Maccoby said. Trump’s relationships “can be extremely close, but you never know whether he’ll change his mind.”

“The only people that he remains loyal to are his actual family,” he added.