If Trump wants his approval ratings to keep sinking, he should definitely stay the course. Or, like the Fonz in those classic episodes of “Happy Days,” he can admit he was wr … wr … wrong. And then he can make it someone else’s problem to fix the mess.

Why force yourself to fire another senior aide every few weeks or months, like a slow bleed? Better to replace poor Priebus now and let Christie deal with the unpleasantness of fixing things. (If there’s one thing Christie doesn’t mind, it’s unpleasantness.)

A chief of staff can elegantly reboot the system in a way a president can’t. A chief of staff can simply say: “I didn’t hire any of these guys, and I’m letting them go.” Done.

Look, it’s not my job to offer Trump advice on his presidency, and it’s not like he’d listen. Maybe it’s true that we’re all better off if the whole experiment craters in the first six months.

But that’s a pretty big risk to take, and if I were Trump, I’d call Christie back today and tell him I need some order and professionalism in the West Wing.