Trump privately resents the now-regular chatter on cable television news shows about his mental health and views the issue as "an invented fact" and "a joke," much like the Russia probe, according to one person who recently discussed it with him.
Doubts about Trump's state of mind have been whispered about in Washington's corridors of power since before he was elected and have occasionally broken into the open, such as when Sen. Bob Corker (R-Tenn.) said last August that Trump lacked "the stability" and "some of the competence" to be successful as president.
But Wolff's book has thrust the topic to the forefront of public debate, prompting the White House to confront the issue directly.
So far, Trump's advisers have adopted a posture of umbrage and indignation. Rather than dignifying questions about whether their 71-year-old boss is fit to be president, they attack the inquisitors for having the gall to ask.
In an emailed statement Monday, White House press secretary Sarah Huckabee Sanders slammed what she called "ridiculous reports from detractors" and described an "outpouring of support from a totally indignant staff."
"The White House perspective is outrage and disgust that people who do not know this President or understand the true depth of his intellectual capabilities would be so filled with hate they would resort to something so far outside the realm of reality or decency," she said.
Asked Monday by reporters whether Trump's physical exam, scheduled for Friday at Walter Reed National Military Medical Center, would include a psychiatric component, deputy White House press secretary Hogan Gidley barely engaged the question. He replied, simply, "No."
Former Trump campaign adviser Jason Miller charged that there were partisan motivations behind the talk of Trump's fitness. "The political left wants this to become a debate about made-up attacks against the president rather than the president's successes and the success of the country," he said. "This is a pretty pathetic move."
White House officials are trying to present Trump as hard at work doing his job. A long-planned working retreat at Camp David over the weekend became a showcase for the commander in chief.
The traveling pool of reporters was invited to the presidential getaway in Maryland, where Trump parried their questions Saturday while Vice President Pence, Cabinet members and Republican congressional leaders flanked him with approving nods and applause.
"Just from a visual standpoint, it shows a very united front," one White House official, who spoke on the condition of anonymity to share an internal assessment, said of the Camp David news conference. "Everyone's on the same page. There are no fractures. From an optics standpoint, it works very well."
Scott Reed, a veteran Republican strategist who works for the U.S. Chamber of Commerce, said Trump can best help extinguish emerging doubts by advancing his policy agenda, including proposals for new spending on infrastructure projects. "This needs to move beyond talking heads and be met with action and discipline," Reed said.
U.S. Ambassador to the United Nations Nikki Haley also fired back against critics on ABC's "This Week" on Sunday, emphasizing the president's accomplishments rather than his state of mind.
"As much as everyone wants to talk about stability, was he unstable when he passed the tax reform?" she asked. "Was he unstable when we finally hit back at Syria and said no more chemical weapons? Was he unstable when we finally put North Korea on notice? Was he unstable when he said, 'Wait, we need to look at Iran because this is getting to be a dangerous situation'? Was he unstable with the jobs or the economy or the stock market?"
But Monday, as Trump delivered a speech on agriculture policy in Nashville, neither CNN nor MSNBC carried his full remarks live. Instead, anchors Jake Tapper and Nicolle Wallace, respectively, interviewed journalists and pundits about Wolff's book and Trump's reaction to it.
Some Trump allies voiced frustration that the White House does not appear to have implemented a full-scale crisis communications plan.
"When you raise an issue like the mental acuity of the president, there is no organized effort to push back," said one ally, who spoke on the condition of anonymity to talk candidly. "How do you disprove a fallacy?"
After several days of blanket coverage of Wolff's book, the Republican National Committee sent some talking points to Trump allies Friday evening. The memo, titled "Pundit Prep," urged Trump's defenders to first focus on "jobs, jobs, jobs," and offered tips on discrediting Wolff and his tome. The document did not address how to answer questions about Trump's fitness for office.
White House officials said organizing a public response has been relatively easy, as administration aides and allies have been naturally frustrated and eager to push back. A number of Cabinet members and other people who have worked closely with Trump over the years have come forward with testimonies of the president's mental capacity.
"He is absolutely no different than the day he got elected, and he has used this unconventional but very effective manner of managing for the 30 years that I've known him in business, finance, media and now governing," Thomas J. Barrack Jr., Trump's longtime friend and inauguration chairman, said in an interview Monday.
"It's not mental instability," Barrack added. "It's management by controlled and orchestrated chaos."
Agriculture Secretary Sonny Perdue said Monday on Hugh Hewitt's radio show that his boss is "focused, he's determined, he's a business guy. He asks tough questions, and expects solid answers."
When Hewitt asked if Trump was "really smart," as the president claimed in his tweet, Perdue replied: "I think he is really smart. He's instinctive. He has a unique, inherent gift of just being able to figure stuff out. It's like street smarts."
CIA Director Mike Pompeo, appearing Sunday on CBS's "Face the Nation," talked about Trump's engagement during the near-daily intelligence briefings that Pompeo helps deliver.
"We engage in complex conversation about some of the most weighty matters facing the world," Pompeo said, adding: "He asks really hard questions. He delivers policy outcomes based on the information that we provide him."
A more combative defense came from Stephen Miller, Trump's senior policy adviser, who tangled with Tapper on Sunday on CNN's "State of the Union." Miller trashed Wolff as "a garbage author of a garbage book."
"One of the other tragedies of this grotesque work of fiction is its portrayal of the president," Miller said. "The reality is, is the president is a political genius."
As Miller repeated himself again and again, he and Tapper began talking over each other, and the interview grew so contentious that the CNN host eventually cut it — and Miller — off.
Afterward, Miller was delighted. He told others he was proud of his performance and thought the exchange went well. So did the president, who chimed in with Twitter praise, saying his policy adviser had "destroyed" the "Fake News" Tapper.
Josh Dawsey contributed to this report.