Donald Trump has given no indication that he cares very much about what former White House officials think of him.
But following the firing of Andrew McCabe from the FBI, the reaction of John Brennan, who was CIA director until January of last year, is astounding.
Brennan tweeted: "When the full extent of your venality, moral turpitude, and political corruption becomes known, you will take your rightful place as a disgraced demagogue in the dustbin of history.
"You may scapegoat Andy McCabe, but you will not destroy America… America will triumph over you."
They are the words of one man but they reveal the depths to which relations have plunged between the President and some in the security and intelligence community.
Trump has spent weeks insulting and pressuring his attorney general Jeff Sessions to fire McCabe.
The decision came 26 hours before McCabe was due to retire after 21 years at the bureau and consequently might impact his ability to draw his government pension.
McCabe is one of many who do not buy the official reason for his dismissal – that it was the cost of his handling of the investigation into Hillary Clinton's private email server before the 2016 election.
He says he is being singled out because of his support for the fired former FBI director James Comey and that "it is part of this administration's ongoing war on the FBI".
Trump was jubilant after McCabe's firing, calling a "great day for democracy" and saying: "He knew all about the lies and corruption going on at the highest levels of the FBI!"
Andrew McCabe FIRED, a great day for the hard working men and women of the FBI – A great day for Democracy. Sanctimonious James Comey was his boss and made McCabe look like a choirboy. He knew all about the lies and corruption going on at the highest levels of the FBI!
— Donald J. Trump (@realDonaldTrump) March 17, 2018
He believes America's top law enforcement agency is biased against him and that senior figures tried to derail his election chances.
But, while all this goes on, the Special Counsel Robert Mueller, himself a former FBI director, continues his long and methodical investigation into the Trump campaign's links to Russia and whether the President obstructed justice over that investigation.
McCabe is reported to have kept memos, just as Comey did, of his interactions with the President. Those documents might be of interest to Mueller.
Spent very little time with Andrew McCabe, but he never took notes when he was with me. I don’t believe he made memos except to help his own agenda, probably at a later date. Same with lying James Comey. Can we call them Fake Memos?
— Donald J. Trump (@realDonaldTrump) March 18, 2018
On Sunday, Mr Trump tweeted: "Spent very little time with Andrew McCabe, but he never took notes when he was with me.
"I don't believe he made memos except to help his own agenda, probably at a later date. Same with lying James Comey. Can we call them Fake Memos?"
There are those who fear that Trump's tirades over Russia are the lead-up to him attempting to fire Mueller's boss, deputy attorney general Rod Rosenstein, or trying to force out Mueller himself.
Opponents of the President warn darkly that such action would prompt a constitutional crisis but there is no telling which way Trump loyalists would turn faced with a president shutting down an investigation into his own conduct.
In such a partisan climate with ever-mounting evidence of Russian meddling and a president who feels victimised and is prone to lashing out, few are willing to predict what will happen next.
More from Analysis
The man who built a television career telling people they were fired on The Apprentice is said to be weighing up more dismissals among his White House cabinet.
He is said to enjoy a bit of "chaos". The American people might be finding it a little less enjoyable.