Donald Trump wanted Hope Hicks close.

When the new President and his team moved into the White House last January, he installed his long-serving press aide in a tiny, windowless room directly outside the Oval Office. He could shout at her to bring him the latest news clips and polls. He could summon her to his private office next door to watch television coverage. Above all, he felt, he could trust her — she was a rare, reassuring support in his new digs in a new city filled with newcomers he didn’t know well.

Which is why the news of Hope Hicks resigning, which broke late Feb. 28, comes as such a blow to the Trump White House. “I cannot over-state how important Hope is to keeping this thing together,” one West Wing official said. “She really is one of the only people who has the President’s trust and respect.” In a building riven with suspicion and infighting, presided over by an unpredictable, some would say irrational, boss, a key pillar of support is leaving.

Hicks, a 29-year-old former model who had zero political experience before Trump hired her to be a one-woman communications shop for his campaign, enjoyed influence over Trump far beyond the typical White House communications director. She weighed in on foreign policy, domestic politics, media strategy and Cabinet management. She had a greater ability to steer Trump than either of his chiefs of staff so far, and could read him in ways others on staff could not. Hicks was perhaps the only person outside the Trump family who could, from time to time, control the volatile President.

“She’s the Trump whisperer. When I need the President to take something seriously, I ask Hope to bring it up,” a second White House official said. “The President listens if she brings it up. He knows she doesn’t waste his time.”

That’s not to say she was widely liked inside the West Wing. She could have sharp elbows and was a master of the internal knife-fight. She was young for the job and came without a pedigreed political resume.

Yet what she lacked in experience she more than made up for it with the one currency Trump prizes above others: loyalty.

White House chief of staffs Reince Priebus and John Kelly each had been surprised to walk by the Oval Office to see the President speaking with reporters. She was a more powerful gatekeeper than the nominal bosses, a perk of being a media-obsessed President’s chief media strategist. Fights with Hicks seldom were won by anyone other than Hicks herself. She reported directly to the President and took her orders from him alone. Like the President, she didn’t care about precedent or protocol.

Her exit is the highest profile from Trump’s inner circle, and it has implications for the whole of government.

Trump relied on Hicks constantly. Part of it was that she was a welcome reminder of his unlikely campaign that saw a never-before-politician beat better prepared rivals for the Republicans’ presidential nomination and then bested the superior machinery of the Clinton campaign. Part of it was that she never crowded him out of the spotlight. She was the rare White House communications director who didn’t give on-the-record interviews, appear on cable news or Sunday shows, and shunned attention. In fact, when GQ wrote a profile of her in 2016, she declined the interview request and instead arranged for Trump to tell her story while she listened in.

And part of it was that she didn’t try to make Trump into anything than what he is. She didn’t confiscate his Twitter account. She didn’t try to bend him to be a more traditional leader. She didn’t force him to do anything he didn’t want to do. Much of the time she enabled his worst qualities, only occasionally boxing out his worst instincts. On the rare days she told the President no, he listened.

White House officials said Hicks’ last day was still being determined. A search for a replacement hasn’t yet begun. She had begun telling senior West Wing officials in recent days but hadn’t yet briefed the 40 or so aides who work under her in the press, speechwriting, research and social media departments when the news broke in the New York Times.

The role of communications director has been a cursed one with this Administration, and Hicks formally took the role only after four others had been announced and dismissed. The first choice, Jason Miller, bowed out amid reports of a child conceived with his mistress. Press secretary Sean Spicer twice wore the hat on an interim basis. Michael Dubke did the job for 88 days, two days shy of being forced to comply with ethics rules. And Anthony Scaramucci did it for 10 days before being shown the door for impolitic and profane comments about colleagues.

Hicks’ ride in the White House has been anything but smooth. Initially tapped for the role of director of strategic communications — a title that largely entailed handling press requests involving the President or his family — she was elevated to the top communications role during the summer. Yet every controversy and potential crisis ran through her cell phone, which was constantly affixed to her ear whether she was in the White House, on the town, traveling with the President for campaign rallies or jetting around the globe.

It was on one of those foreign trips that she helped write a now-problematic statement about Trump officials’ meeting with Russians. That conversation was central to her nine-hour meeting with House lawmakers on Tuesday and could prove significant for special counsel Robert Mueller’s investigation. Congressional officials say the grilling left Hicks visibly shaken, although White House officials cautioned against linking her trip to Capitol Hill with her decision to exit.

She was also at the center of a botched response to allegations that a top White House official faced accusations he abused his two ex-wives. Hicks was dating the aide, White House staff secretary Rob Porter, according to multiple White House sources familiar with the relationship.

Hicks will remain influential even after she leaves the White House. If Trump trusts someone, he will phone them for counsel even after they’ve officially stepped out of their role. Trump himself nodded to that in a statement praising Hick’s tenure with him.

“I will miss having her by my side, but when she approached me about pursuing other opportunities, I totally understood,” he said. “I am sure we will work together again in the future.”

There’s little chance she’s won’t be a key player in the President’s re-election bid in 2020.

Get our Politics Newsletter. The headlines out of Washington never seem to slow. Subscribe to The D.C. Brief to make sense of what matters most. Please enter a valid email address. Sign Up Now Check the box if you do not wish to receive promotional offers via email from TIME. You can unsubscribe at any time. By signing up you are agreeing to our Terms of Use and Privacy Policy . This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. Thank you! For your security, we've sent a confirmation email to the address you entered. Click the link to confirm your subscription and begin receiving our newsletters. If you don't get the confirmation within 10 minutes, please check your spam folder.

Write to Philip Elliott at philip.elliott@time.com.