Why is a mayor who styles himself the champion of the working stiff so bent on destroying jobs for working people — and doing it at the behest of some of this city’s most well-heeled political donors?

The last time Bill de Blasio tried to ban horse carriages, he took a drubbing from New Yorkers who made it amply clear they want to keep the horses and they want the horse-carriage drivers to keep their jobs.

Now the mayor’s back at it, with a new ban he plans to submit to the City Council. George Miranda, president of Teamsters Joint Council 16, puts it this way: “This is awful news to give a working family just before the holidays.”

What explains this determination to impose a ban that will deprive any number of honest, hardworking folk of their livelihoods? The answer is this is Mayor Tale of Two Cities paying back his rich pals.

Through a group called NYCLASS, Bill’s wealthy friends pumped hundreds of thousands of dollars into an effort aimed at sinking the campaign of de Blasio’s chief primary foe, then-Council Speaker Christine Quinn.

These financial transactions are now under FBI investigation, but they did the trick: They helped sink Quinn.

When the mayor first moved against the horses this year, he aimed to replace them with some as-yet-to-be-built Rube Goldberg antique-auto reproductions.

Now he promises the horse-carriage drivers medallions that would let them drive cabs that serve the outer boroughs — which none of them want.

Think of “Let them drive green cabs” as the progressive update for Marie Antoinette’s “Let them eat cake.”