Et tu Donald? The president appears to drop his most loyal foot soldier

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.