A senior official inside Donald Trump's White House has claimed staff try to act as a brake on the president's behaviour.
The anonymous official said "the erratic behaviour would be more concerning if it weren't for unsung heroes in and around the White House".
"It may be cold comfort in this chaotic era, but Americans should know that there are adults in the room," they say in The New York Times.
The White House said the author of op-ed was a "coward" who should "do the right thing and resign".
The official wrote 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".
"I would know - I am one of them," the aide said.
"To be clear, ours is not the popular 'resistance' of the left.
"We want the administration to succeed and think that many of its policies have already made America safer and more prosperous.
"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.
"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."
Trump tweeted back, suggesting: "The failing New York Times has an anonymous editorial - an you believe it? Antonymous. Meaning gutless, a gutless editorial".