Of all the grifters and cranks to attach themselves to outgoing President Donald Trump’s traveling circus, perhaps the one with the most to lose — apart from Ben Carson — is Rudy Giuliani.

He could easily have gone down in history as an overzealous US attorney who took on the mafia and patented the “perp walk”, or as a fantastically overrated New York mayor, largely on account of the fact he happened to hold the office on September 11 2001, and gave the public the hard-line response it wanted.

Now, after two years as turning up as a crazed and incoherent defender of Trump across the media (and even more humiliatingly in the latest Borat movie) Giuliani is a walking punchline. And he’s learning what everyone who works with Trump eventually learns — the president is petty, can’t regulate his emotions and doesn’t pay his bills.

Trump, cranky at being the first US president in history to be impeached twice, has reportedly told his staff to stop paying Giuliani’s legal fees — which was not, he insists, $20,000 a day.

So how did it come to this, Trump ditching one of the few confidantes to not jump ship (a ship now in the “splitting in half” portion of sinking) in the administration’s horrifying final weeks?

A fascinating profile in Politico casts their relationship as a complicated and

… predominantly transactional one, a function of proximity, pragmatism and a kind of philosophical kinship. Starting in the ‘80s, they weren’t friends as much as self-created characters on the same bustling, spot-lit, tabloid-stoked stage, ferociously and transparently ambitious players in New York’s nexus of money, publicity and power

It’s noteworthy that it’s over money and hurt pride that Trump finally distances himself from Giuliani — not, say, the series of bizarre television appearances in which the latter claimed “collusion isn’t a crime” and that the president would be well within his rights paying off the women he’s had affairs with.

A clue as to why came in November 2019, from an anonymous former White House staffer who told The Atlantic, “the reality is that Donald Trump only has, like, six or seven friends in his life. And Rudy is one of them”.

Giuliani has repeatedly joked that he “knows too much” about Trump to be fired, precisely the kind of thing you want your defence attorney saying in public.

Trump only has a few days left in office and is maybe the most isolated president in history. (Will he even get the round of applause Nixon’s cabinet gave him?)

He’s lost access to social media, brands are abandoning him, people are turning down his offer of awards.

According to The Washington Post he is furious at press secretary Kayleigh McEnany, senior adviser/son-in-law Jared Kushner, economic adviser Larry Kudlow, national security adviser Robert C. O’Brien and chief of staff Mark Meadows for failing to publicly defend him.

Current and former administration officials (speaking anonymously, naturally) told the Post that everyone still in the White House is simply too exhausted to mount another vigorous conspiratorial defence of Trump.

And now, it appears, the one guy who never flagged in that task is on the outside too.