(CNN) –– An unnamed senior Trump administration official assailed President Donald Trump’s “amorality” and reckless decision-making in a New York Times op-ed published Wednesday and said he is part of a “resistance” working to thwart Trump’s worst impulses.

“The dilemma — which (Trump) does not fully grasp — is that many of the senior officials in his own administration are working diligently from within to frustrate parts of his agenda and his worst inclinations,” the Times piece reads.

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“I would know. I am one of them.”

The Times said disclosing the name of the official, who is known to the publication, would jeopardize the official’s job, and said publishing the piece anonymously was the only way to deliver an important perspective to readers.

Major newspapers almost never publish unnamed op-ed pieces. At The New York Times, it is very rare, but not quite unprecedented.

Trump dismissed the op-ed as “really a disgrace” and “gutless,” assailing the author and The New York Times for publishing the anonymous opinion piece.

“We have somebody in what I call the failing New York Times that’s talking about he’s part of the resistance inside the Trump administration,” Trump said. “This is what we have to deal with. And you know the dishonest media … But it’s really a disgrace.”

Trump assailed the anonymously bylined article as a “gutless editorial.”

He then pivoted to his accomplishments, claiming that “nobody has done what this administration has done in terms of getting things passed and getting things through.”

Corroboration for Woodward’s book

The op-ed offers a first-hand account that corroborates key themes of a new damning book about Trump’s presidency by the veteran journalist Bob Woodward: that some of the President’s top advisers have a dim view of the commander in chief and are quietly working to thwart Trump’s most reckless and impulsive decisions from becoming a reality.

The author writes the resistance inside the Trump administration is not the same “resistance” of the left against Trump and said he and like-minded colleagues working to thwart some of Trump’s actions “want the administration to succeed … But we believe our first duty is to this country, and the president continues to act in a manner that is detrimental to the health of our republic.”

“That is why many Trump appointees have vowed to do what we can to preserve our democratic institutions while thwarting Mr. Trump’s more misguided impulses until he is out of office.”

The result, the official writes, has been a “two-track presidency” in which Trump’s own worldview — uttered both in public and private — diverges from some key actions taken by the administration, like those involving additional sanctions against Russia.

A dramatic alternative to the quiet effort to thwart some of Trump’s more concerning actions was, however, considered, the official said: invoking the 25th Amendment.

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The official alleges there were “early whispers within” Trump’s Cabinet of invoking the 25th Amendment, which would require a majority of Cabinet officials to declare to Congress they believe the President is “unable to discharge the powers and duties of his office.”

Explaining the “resistance” effort, the senior administration official offers a damning portrait of Trump’s character and leadership ability.

The author argues the “root of the problem is the President’s amorality” and assails Trump’s “reckless decisions,” “erratic behavior” and what he describes as Trump’s “impetuous, adversarial, petty and ineffective” leadership style.

“The root of the problem is the President’s amorality. Anyone who works with him knows he is not moored to any discernible first principles that guide his decision making,” the official writes. “Although he was elected as a Republican, the President shows little affinity for ideals long espoused by conservatives: free minds, free markets and free people.”

Extensive insights

The senior administration official’s op-ed offered extensive insights into the unvarnished thoughts of a top official, but the op-ed was in keeping with reports throughout Trump’s presidency. In those reports, numerous senior administration officials have described Trump’s impulsive decision-making and the chaos that has often animated the President’s inner circle.

It’s both a confirmation of the portrait of the President painted by Woodward and reporters covering the Trump administration as well as an attempt at reassurance.

“It may be cold comfort in this chaotic era, but Americans should know that there are adults in the room. We fully recognize what is happening. And we are trying to do what’s right even when Donald Trump won’t,” the official writes. “This isn’t the work of the so-called deep state. It’s the work of the steady state.”

White House press secretary Sarah Sanders also issued a scathing statement in response to the op-ed.

“The individual behind this piece has chosen to deceive, rather than support, the duly elected President of the United States,” she wrote. “He is not putting country first, but putting himself and his ego ahead of the will of the American people. This coward should do the right thing and resign.”

A Times spokeswoman said op-ed anonymity had been granted a handful of other times in the paper’s history, most recently for a piece in June by an unnamed asylum seeker from El Salvador.

In this case, The Times said it granted anonymity “at the request of the author” because the person’s job “would be jeopardized by its disclosure.”

The newspaper also pointed out that its opinion editors know the person’s identity, so he or she is anonymous to the public, but not to the Times.

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CNN’s Brian Stelter contributed to this report.