Public-school teachers across New Jersey just got utterly robbed by their union, the New Jersey Education Association, to the tune of $40 million.

That’s how much the NJEA-funded super PAC Garden State Forward dumped into into Working New Jersey, the independent expenditure group supporting Montclair Mayor Sean Spiller . . . whose other main job is running the NJEA.

Spiller’s own campaign raised an anemic $438,000; he finished fifth in the six-person Democratic primary.

By the way, Garden State Forward also gave another “independent” outfit, Protecting Our Democracy, $5 million over 2022-’23 promoting Spiller in advance of his gov run.

That’s $45 million that the union boss spent on promoting himself.

And Spiller still had the chutzpah to claim that his loser had the backing of “working folks.”

But it wasn’t the voluntary backing, was it Sean?

The NJEA’s own writeup of the results talked of a “strong showing” from Spiller, “a nontraditional candidate” whose “people-powered” campaign the pundits dismissed.

Of course the pundits were right — and the teachers were robbed.

Whether or not NJEA teachers oust their boss in the next union vote, the new governor and Legislature should look to prevent any repeat of this outrage.

“Everything’s legal in New Jersey,” goes the “Hamilton” joke, but Spiller’s outrageous self-dealing still sets a new low in Garden State political stench.