I keep circling back to a description that Donald John Trump hung on his presidential administration.

He has called it a “fine-tuned machine.” He meant, I presume, to suggest that the administration was firing on all cylinders, that is purring like a kitten, that it is well-lubed/oiled. Pick whatever metaphor you think the president intended.

Now we have yet another example of that machine grinding its gears. It has flown off the rails. It’s in the ditch … yet again.

The White House has stumbled back into crisis management mode. Chief of staff John Kelly is under intense examination for the way he handled — or mishandled — the circumstances surrounding former staff secretary Rob Porter and the allegations that he beat up his two ex-wives and a former girlfriend.

Porter has quit. A speechwriter has quit because of allegations that he abused his former wife.

The question at hand is what Kelly knew and when he knew it. He denies knowing long ago that Porter had been suspected of spousal abuse. There has been credible reporting that Kelly did know months ago, long before it all blew up this past week.

The president reportedly is angry over what Kelly knew and what he didn’t divulge to the boss — that would be Trump — about the questions regarding Porter’s conduct.

Media have reported that Kelly offered to resign. Kelly denies making that offer. White House officials are now struggling to clear up the “message” coming from the West Wing.

Chaos has revealed itself again at the White House.

We are not witnessing a “fine-tuned machine” at work. What we are watching is a jalopy in need of yet another major overhaul.