Donald Trump may favor stodgy blue suits and boring red ties and wear his hair in a strange double combover, but don’t be fooled. That’s how he looks, not who he is. Who he is is a guy with a safety pin through his nose and a purple mohawk. He just pulled off the most punk act in American history.

If you’re a Hillary Clinton voter, or a member of the average media outlet, observing the Trump phenomenon to you was like watching Frank Sinatra in the 1970s: has-been, used-up, going through the motions appealing to a rapidly disappearing demographic, relying entirely on crusty oldies like “My Way.”

Yet the version of “My Way” Trump actually represented was the one gargled by Sid Vicious, the short-lived Sex Pistol, over the closing credits of “Goodfellas” — crude, sneering, shocking, postmodern. None of us could believe what Trump was doing — because no one had ever seen anyone do it that way before.

“Stop Pretending — Donald Trump Is Not Running for President” ran the headline of an amazingly wrong column in The Post on May 30, 2015. (For that little flub, Trump rewarded me with a mention in his most recent book, sarcastically dubbing me The Post’s “resident genius.”)

I could not decipher Trump. Who could? He was inventing a new language of politics on the fly. He was operating at another level.

Every Republican — including, as recently as 2012, Trump! — said a Republican could not get elected president without making inroads among Latino voters.

And Latino voters, everyone believed, really did not want to hear about crackdowns on illegal immigrants.

So Trump said he was going to crack down on illegal immigrants.

“When Mexico sends its people, they’re not sending their best,” he said in his freewheeling campaign kickoff speech. “They’re not sending you; they’re not sending you. They’re sending people that have lots of problems, and they’re bringing those problems with us. They’re bringing drugs. They’re bringing crime. They’re rapists, and some, I assume, are good people.”

Only “some” Mexican immigrants are good people? It’s like when a punk singer spits on his audience. According to exit polls last night, Trump actually did slightly better than Mitt Romney among Latinos — 29 percent against Mitt’s 27 percent.

Remember when somebody mentioned the sainted war hero John McCain and Trump wisecracked that he couldn’t be that much of a hero if he got caught? Punk!

Remember when he promised a big announcement that he was ready to concede that President Obama was actually born in the United States and every news hound covered it as if it were the Super Bowl? He turned it into an infomercial for his new Trump hotel in the Old Post Office building on Pennsylvania Avenue in DC.

Hey, what’s more punk than shameless love of filthy lucre?

Remember when Hillary Clinton, Lisa Simpson-like, was busily organizing a landslide?

She did everything by the book. She amassed a prim little army of do-gooders, covering her bases by opening proper little field offices in every burg in America, even in Dallas and Houston. Trump scoffed, and sent out some 3 a.m. tweets. (Hillary, we learned from WikiLeaks, once needed 12 staffers and 12 hours of deliberation to craft a single tweet.)

Even Trump himself often seemed so ambivalent about the position he found himself in that the most seasoned political reporters openly wondered if he even wanted to win.

Just not giving a flying fig is the quintessence of punk.

Trump didn’t just throw out the playbook, he set fire to it. And America loved it. Not releasing his taxes? Fine, said America — can you help us game the system too? So antagonizing the media that major news outlets dropped all pretense of neutrality and openly campaigned against him? Not a problem, said America — we hate those sons of bitches too, and the enemy of our enemy is our friend.

Punk is the art of taking the stage with no preparation whatsoever and screaming: It’s me against the world, and what the freak are you gonna do about it?

The last year-and-a-half it was Trump against the world, and the world lost.