“Tax the rich!” That used to be the sort of sentiment you might expect from a student who’d just discovered a bit of Marxism and had yet to pay their first tax bill. But now New Yorkers are lucky enough to have a mayor who thinks this dumb slogan should be turned into policy.

Why is it dumb? For several reasons. Not the least of which is that it is so misleading. Saying “Tax the rich” suggests that the rich aren’t already taxed. In fact, the wealthiest people in this city already pay more than their fair share of taxes.

As Mayor Zohran Mamdani and his merry band of Marxists must know by now, the top 1% of New York taxpayers are responsible for almost half of the total tax revenues of this city. To put it another way, 99% of New Yorkers only cover 50% of the tax revenue of this city.

I suppose “Tax the 99%” doesn’t quite have the same ring to it. And it doesn’t play to that sweet cocktail of resentment and envy that always underlies the policies of the far left.

As it happens, the other 99% of us New Yorkers may be about to learn the hard way what it looks like when you try to make the 1% enemies of the state.

Mamdani’s creepy, stalky video outside the New York apartment of financier Ken Griffin has already proven where Hizzoner’s student politics lead.

After smugly doxxing one of New York’s most successful residents, what did our mayor achieve? Only making Griffin literally take his business elsewhere.

Didn’t work in the UK

As The Post reported yesterday, Griffin was so appalled by the mayor’s grinning stunt that Griffin has threatened to scrap his hedge fund Citadel’s $6 billion development on Park Avenue. And who will be the beneficiary of this? Why, Florida, of course. Griffin said this week he is planning on taking more of his business to Miami over the coming years as a “direct consequence of the mayor’s poor decision here with respect to his posting of that video.”

It isn’t an overreaction. After all, this week Gov. Kathy Hochul joined in with Mamdani’s “Tax the rich” antics by deciding to try to fill New York’s fiscal black hole by putting yet another tax on second-home owners in the city. The mayor and governor are scrambling to fill the black hole in the budget. A black hole that is estimated to be somewhere between $10 billion and $12 billion a year over the next couple of years.

That’s a large amount to fill, for sure. But the worst way to try to fill it is to chase the most successful people in New York out of the city.

If anyone doubts that, they should look at the results in other places where left-wing governments have tried a similar formula.

The left-wing Labour government in the UK tried a “Tax the rich” policy after coming into office two years ago. The result? Thousands of multimillionaires simply upped and left the UK.

As I have mentioned here before, there is a big difference between the UK and New York. It is actually quite hard to move your operations, office and life from London to, say, Milan. But thousands of wealthy Londoners did it anyway. By contrast — as Griffin has shown — it is exceptionally easy to pack up and leave New York for Florida.

Thousands of successful New Yorkers have already made the move. Every time I go there, I see more and more of the type of people who until recently made New York the thriving center of their operations.

NYC needs its rich

Even before Mamdani’s election, the city was chasing out our most successful people. Up to 2023, it has been estimated that $660 billion of wealth had already left New York. That’s Hochul and Mamdani’s budget black hole filled many times over right there. In recent years, New York has been the biggest loser of wealth of all the blue states.

That’s quite an accomplishment given the competition.

In California, Gov. Gavin Newsom lies to cover up the fact that his policies have chased out some of his state’s wealthiest taxpayers. Seattle’s strange socialist child-mayor Katie Wilson was recently asked about the flight of capital from her city. Her response was to say that talk of millionaires leaving her state “are, like, super overblown.” Then she added “and if the ones that leave, like — bye,” with which she waved her hand and giggled, getting a whoop of approval from her seal-like audience.

Like Mamdani, Wilson knows how to get cheers from a resentful and math-challenged crowd. But she — and they — will also learn the hard way that their frivolous crowd-pleasing will get less and less amusing by the month.

Because here’s the thing: New York needs our rich. We need them badly. And that means they need to be celebrated, not attacked.

For that to happen, people who believe in success as opposed to envy need to make the case for the rich. We need to explain how — contrary to the claims of AOC and others — billionaires are good. They are good for society, they are good for the economy, and they are good for this city.

Beyond that, there needs to be a proper counterblast from business leaders and others to explain why capitalism is the answer and not the enemy.

Sure, capitalism can have its flaws. But thinking that this means we should make capitalism the enemy is like saying that because water can get polluted, fish don’t need it.

Capitalism is the water in which this great city swims. It is the thing that has made New York one of the great success stories, not just of America, but of the world.

It is time for the adults in this city to tell our mayor that his slogans are like his stunts: very cheap, and very, very costly at the same time.