An idiot president, a moribund legislature and a tribal court.

And a constitution not fit for purpose.

Ain't life grand.

Mutual self-destruction of the old empires of Europe. Dumb luck, really. It just fell into our laps for a century or so. Now, it's our turn for the ash heap.

Alzheimer's or whatever he had near the end and his daughter wanted it known, before he passed, that he was the one who had brought down the Nixon administration. Were it not for anonymous sources, we might never find out as little as we do find out. Heaven knows, whistleblowers are few and far between. (No surprise: Drake, Snowden, Kiriakou, et al.)

But, about the article in The Atlantic quoted in the OP of this thread: Impeachment and the 25th Amendment are expressly provided for in the Constitution. Testifying against a President before Congress or mass resignations are not provided for in the Constitution, but do not violate any provision of the Constitution. That distinction is not vital to this instance, but I think it is worth nothing.

I disagree that "{o}vert defiance of presidential authority by the president’s own appointees" is a constitutional crisis. (And, btw, writing an article anonymously is the opposite of "overt.") A constitutional crisis is something involving more than one branch of government.

If a President were to defy an order of the Supreme Court, we'd have a constitutional crisis. If a President attempted legislation or a declaration of war via an Executive Order and Congress was not inclined to cover his or her ass, we'd have a constitutional crisis. And so on. If Congress subpoenaed a President to testify before Congress under pain and penalty of perjury, under oath, we might have a constitutional crisis.

Insubordination, gossip, etc. by the President's appointees (whom he can fire) about the President is not a constitutional crisis, any more than Deep Throat's ratting out Nixon was a constitutional crisis. (Suppose, instead of giving hints to a reporter for WAPO, Deep Throat had simply written a story for WAPO himself anonymously. Wouldn't that be like the NY Op Ed about Trump?)

If Trump's aides are actually flat out running the country, instead of the person people actually elected, that might be a constitutional issue, but that does not seem to be the case. (BTW, that has happened in the past https://en.wikipedia.org/wiki/Edith_Wilson, Some say it happened with Reagan, too.) If they are only dissuading him from pursuing his worst excesses, isn't advising him against something they believe to be wrong at least part of their job description?

Now, please excuse me while I go hide from angry readers.

... it goes like this:

Intelligence agencies are trying to neutralize a Presidency that somehow managed to get elected instead of their chosen candidate.
Someone at said agency writes an OP-ED for a major newspaper purporting to be from a currently employed senior White House aide. They use their contacts at said newspaper to get it published anonymously contrary to their standard policy.
The intent is to drive the President to distraction looking for Commies traitors under the bed. Nobody trusts anyone, and the President trusts no one. Nobody even dares make a phone call for fear of who is listening or fear of appearing to leak information. Real aides look for opportunities to stab one another in the back (figuratively. probably).
The whole administration is tied in knots. Mission accomplished.
Nah. Nobody would ever believe that. (pulls paper out of typewriter, crumples it up and tosses it into the wastebasket).

democracy is supposed to work, they'd have understood that the Republicans' refusal to allow Obama to govern, including their refusal to even pretend to address his various judicial and executive appointments, was the constitutional crisis. Instead, the Republicans pointed at the Constitution and relied on "Doesn't say we have to" and "Doesn't say we can't" as argument to seditiously undermine the operation of the supposedly democratically elected small-r republican government of these United States.

as it happens, the constitution both defines and provides for the treatment of treason, but doesn't address sedition/usurpation at all. this is a serious shortcoming, because serious treason is both rare and of little interest to most of us most of the time, whereas sedition is always happening, and affects all of us, always.