Homeland Security Secretary John Kelly was abruptly named the White House chief of staff late Friday afternoon. But not before getting assurance from President Donald Trump that he would have full authority within the confines of 1600 Pennsylvania avenue, sources tell The Daily Beast.

“From what I understand, everything and everyone now goes through him,” a senior White House official told The Daily Beast on Friday. Kelly is “the new alpha dog.”

Whether those assurances come true will determine the success of Kelly’s tenure as he takes over for a Reince Priebus, the now former chief of staff whose authority was often undermined and whose position was increasingly marginalized by Trump during his tumultuous six months in the post. Priebus’s tenure, the shortest ever for a White House chief of staff, hit a fever pitch this week as internal White House drama spilled into public in ugly fashion.

Priebus said that he offered his resignation on Thursday. But his actual exit could not have been more brutal or unceremonious. He accompanied the president on a trip to Long Island, was on Air Force One when Trump tweeted out the news of his departure (to the surprise of White House staff) and was left sitting in a car as the press corps came by to ask questions. Ultimately, his vehicle peeled off from the presidential motorcade, drifting alone through the pouring rain to an unknown destination as Trump and company returned to the White House.

Six months in, Trump has fired or replaced his chief of staff, his deputy chief of staff, his communications director, his press secretary, his national security adviser, a deputy national security adviser, and one of his White House spokespersons.

It remains to be seen if Kelly will suffer a similar fate or if he will have better luck than Priebus in corralling various White House factions, especially with Trump’s forceful personality at the helm. A senior administration official noted Kelly’s impressive military background, but asked incredulously, “does [he] really think he can control Trump?”

Kelly’s Rise

All evidence within the Trump White House pointed to Priebus’s days being vanishingly numbered—and, to some in the West Wing, Kelly’s stock rising.

Earlier this week, members of Trump’s inner circle—including White House senior adviser and Trump’s son-in-law Jared Kushner and chief strategist Steve Bannon—had pushed the president to tap Kelly. The pitch made to Trump, as one senior White House official described it, was that Kelly was a “solid choice, what we need, a perfect fit.”

Senior aides to President Trump see Kelly as a disciplined manager who will run a tight ship in the West Wing, and whose management style could help reduce the frequency of leaks that the president and his team find so harmful.

“The president has tried multiple times to get the secretary to take this position, for the past couple of months,” a Trump administration official, who was familiar with the president’s thinking on hiring Kelly, told The Daily Beast.

“Given how close things were to going off the rails, we really needed the general in this job,” the official added, speaking anonymously because he was not allowed to discuss the decision by name.

The official said Trump had grown to rely on Kelly in cabinet meetings to bring discipline to the conversation, since taking the DHS job.

Bannon, likewise, respects Kelly as a “tough” military officer, a West Wing official noted. The former also served in the military, and fetishizes military history and often talks gratuitously in military language in regular conversation.

But the two are not ideological kindred spirits. Bannon is a staunch nationalist who takes an incredibly hardline stance on immigration while Kelly has praised an Obama-era program that temporarily protects some undocumented immigrants from deportation. Kelly’s rhetoric on immigration often focuses on the danger it poses to migrants themselves, rather than to Americans.

The Loyal General

The characterization of Kelly as being the “perfect fit” for the chief of staff job by White House officials will be quickly tested. The role often vexed Priebus right up until the moment he was forced out.

Newly minted communications director Anthony Scaramucci, for one, had spent the past week waging open war on Priebus with the explicit blessing of the president. He publicly insinuating that the former chief of staff was a West Wing leaker while calling him a “fucking paranoid schizophrenic.”

A White House official said that the expectation is for Scaramucci to fall under Kelly’s command but, the official also noted that he could, indeed may, still have direct access to the president. Either way, the pairing could be combustible. Priebus, sensing that Scaramucci would play a disruptive role, had tried to block his hiring as communications director last week, as had other senior staffers such as Bannon.

Kelly has already proven his loyalty to Trump, even at his own expense. Though he reportedly wasn’t given advance notice about the president’s hastily-enacted travel ban, he nevertheless took the blame for the botched implementation.

“In retrospect, I s hould have, and this is all on me, by the way, I should have delayed it just a bit,” Kelly testified to the House Homeland Security Committee in February.

In March, after President Trump tweeted that President Obama had “wires tapped” in Trump Tower during the campaign--an allegation that has yet to be supported by any evidence--Kelly told CNN that the president “must have some convincing evidence that took place.”

That willingness to take lumps for the president endeared Kelly to Trump. But as one Priebus ally told The Daily Beast: “Loyalty with Trump is a one way street.” And shortly after he took the chief of staff gig, former Kelly colleagues were warning that he will face some complex challenges in the West Wing.

“I worked closely with him at the Department of Defense, and he cherishes regular order, doesn't suffer fools gladly and hates politics,” said Derek Chollet, assistant secretary of defense for international security affairs under Obama. “So I don't see how this is going to end well for him.”