President Trump and Vice President Pence at the swearing-in ceremony of CIA Director Gina Haspel in May 2018. (Mark Wilson/Getty Images)

To hear President Trump tell it, his administration is, at any given moment, nearly ideal in its composition and capabilities. It is, as he tweeted in September, a “smooth running machine” — never mind that, before the tweet, 15 senior White House and administration officials had quit or been fired and that, in the months since, another eight have joined them. (Since definitions of “senior” can vary, we’re using those officials identified in The Washington Post’s timeline of high-profile departures from the White House.)

What makes those departures particularly tricky isn’t just that those who left undercut the idea that the administration hasn’t hit any speed bumps. It’s also that, in at least a third of the cases, those who departed have offered words of disagreement with or criticism of Trump or his administration.

Below is a review of those who left, the conditions under which they did and what they’ve said about the White House since.

Brenda Fitzgerald, director of the Centers for Disease Control and Prevention who quit Jan. 31.

Criticisms: None.

Rob Porter, staff secretary who was fired Feb. 7.

Criticisms: In Bob Woodward’s book “Fear,” Porter is quoted as saying that “[a] third of my job was trying to react to some of the really dangerous ideas that he had and try to give him reasons to believe that maybe they weren’t such good ideas.”

Hope Hicks, communications director who quit Feb. 28.

Criticisms: None. Hicks works at Fox.

Gary Cohn, director of the National Economic Council who quit March 6.

Criticisms: Cohn is also quoted in “Fear.”

“It’s not what we did for the country,” he reportedly said. “It’s what we saved him from doing.” In another anecdote, Cohn is described as removing a document from Trump’s desk to prevent the president from signing it.

Rex Tillerson, secretary of state who was fired March 13.

Criticisms: It was challenging to “go to work for a man who is pretty undisciplined, doesn’t like to read, doesn’t read briefing reports, doesn’t like to get into the details of a lot of things, but rather just kind of says, ‘This is what I believe,’ ” Tillerson said in an interview. He also said Trump would need to be told when proposed actions were potentially illegal.

Andrew McCabe, deputy FBI director who was fired March 16.

Criticisms: McCabe called Trump’s attacks on him personally “unhinged.” Working at the FBI, he said, “is the best job you will ever have, even if a president decides to attack you and your family.”

H.R. McMaster, national security adviser who was fired March 22.

Criticisms: Before leaving the White House, McMaster was reported to have said Trump was a “dope” who was no smarter than a kindergartner.

David Shulkin, secretary of Veterans Affairs who was fired March 28.

Criticisms: Shulkin claims he butted heads with advocates for VA privatization who “saw me as an obstacle to privatization who had to be removed.”

Tom Bossert, homeland security adviser who was fired April 10.

Criticisms: None. He is employed by ABC News. It’s not clear whether he signed a nondisclosure agreement when joining the White House.

Nadia Schadlow, deputy national security adviser who quit April 11.

Criticisms: None. In a lengthy interview with CBS, Schadlow was complimentary about Trump’s involvement in the security team’s processes.

Ty Cobb, White House lawyer who quit May 2.

Criticisms: “Bob Mueller is an American hero in my view,” Cobb said in an interview in October. “I don’t believe this is a witch hunt.”

Joe Hagin, deputy chief of staff who quit June 19.

Criticisms: None.

Scott Pruitt, Environmental Protection Agency administrator who quit July 5.

Criticisms: None. Pruitt’s departure followed a remarkable string of questions about his behavior at the EPA.

Marc Short, legislative affairs director who quit July 12.

Criticisms: None. Short is a CNN contributor. After signing a nondisclosure agreement while working with the campaign, he says he did not sign one at the White House. (The campaign nondisclosure agreement was expansive in its terms.)

Donald McGahn, counsel who quit Aug. 29.

Criticisms: People close to McGahn told CNN that, in his last meeting with Trump, the president blamed him for the Mueller appointment.

Jeff Pon, Office of Personnel Management director who was fired Oct. 5.

Criticisms: None.

Nikki Haley, U.N. ambassador who quit Oct. 9.

Criticisms: Haley described to NBC News how she leveraged Trump’s personality: “I got the job done by being truthful but also by letting him be unpredictable and not showing our cards.”

Jeff Sessions, attorney general who was fired Nov. 7.

Criticisms: None. Despite ongoing criticism from Trump that ultimately led to his ouster, Sessions told an audience in November that he “enjoy[ed] the honor and appreciate[d] the president allowing me to serve almost two years in one of the greatest jobs in the world.”

Mira Ricardel, deputy national security adviser who was fired Nov. 14.

Criticisms: None.

John F. Kelly, chief of staff who was fired Dec. 8.

Criticisms: Working as chief of staff was a “bone-crushing hard job,” Kelly said in an interview with the Los Angeles Times. Trump never asked him to do anything illegal “because we wouldn’t have.”

Nick Ayers, vice president’s chief of staff who quit Dec. 9.

Criticisms: None. Ayers did, however, decline a job that Trump had made very clear he hoped Ayers would accept.

Ryan Zinke, secretary of the Interior who quit Dec. 15.

Criticisms: None.

Jim Mattis, secretary of defense who quit Dec. 20.

Criticisms: “[O]ur strength as a nation is inextricably linked to the strength of our unique and comprehensive system of alliances and partnerships,” Mattis wrote in his resignation letter. “My views on treating allies with respect and also being clear-eyed about both malign actors and strategic competitors are strongly held and informed by over four decades of immersion in these issues,” he added, remarking that he was leaving because Trump had “the right to have a Secretary of Defense whose views are better aligned with yours on these and other subjects.”