Big Bill de Blasio rolled into City Hall’s Blue Room Friday, blowing smoke like an old-timey steam locomotive and demanding New Yorkers believe absurd lies about his role in the Eric Garner affair.

“I believe my role is to respect this process and respect the state law,” says the man who respects nothing and nobody — not process, not law and certainly not the intelligence of his constituents.

That’s just Lie No. 1.

Here’s Lie No. 2.

“I hope today begins the process of restoring some faith,” de Blasio said, shortly after it was announced that an NYPD administrative judge had recommended firing the cop who wrestled a violently resisting Eric Garner to the ground during an ill-starred ­arrest five years ago.

“We have a lot more work to do.”

Work? Park Slope gym rat Bill de Blasio fretting about work? How novel.

But shouldn’t he have begun the “process” of faith restoration five years ago?

That is, back when Garner’s multiple physical infirmities and short temper collided with a police assignment to enforce public-nuisance laws on Staten Island — ending badly for Garner, for Police Officer Daniel Pantaleo and for New Yorkers’ (obviously ­naïve) belief that they elect mayors to tackle hard problems.

And to leave the presidential politicking to others.

Yet there was Kaiser Wilhelm the other night, flapping his arms on global TV and lamenting the Garner case — as if his sole responsibility in the matter has been to observe closely and report back.

And never to exercise executive leadership. (Can one imagine Rudy Giuliani or Mike Bloomberg allowing this case to fester for five full years? Certainly not.)

Yet even Friday, de Blasio crossly refused to say whether he’ll instruct Police Commissioner James O’Neill to follow the judge’s recommendation and fire Pantaleo.

No, he was busily respecting the process — which in Wilhelm World appears to be to drag the case out even longer; to further degrade the public’s confidence in the NYPD; to shred police morale and to offer aid and comfort to the social parasites who feed off a great city’s inevitable misfortunes and discontents.

That is, de Blasio condemned the US Justice Department for failing to do what a medical examiner couldn’t justify, and what a district attorney refused to do — prosecute a crime that never occurred.

Did Eric Garner deserve to die for selling loose cigarettes? Of course not.

Did he bring trouble on himself by violently refusing to submit to a legitimate arrest — considering his diabetes, his asthma and his advanced coronary disease? That seems obvious.

Did Daniel Pantaleo cause Garner’s death by applying an illegal chokehold during the struggle? The Staten Island DA didn’t indict, and US Attorney General William Barr explicitly said no.

Now here’s where it gets tricky. New York law explicitly carves out protections for cops engaged in good-faith enforcement. It allows for heat-of-the-moment errors of judgment, for accidents and for unhappy outcomes. For human frailty, in other words.

That is, by law, cops get the benefit of the doubt — and only insane people would take the job if they didn’t get that benefit.

The Eric Garner case was — and remains — a swirling, politically charged mess. But the political thickets are where mayors are supposed to live — the better to resolve conflict and restore confidence in public institutions.

To lead, not to lie.

Bill de Blasio fails on both counts.

Bob McManus is a contributing editor of City Journal. Twitter: @rlmac2