MICHAEL GOODWIN: New York City’s booming economy is bad news for the far left.

Gov. Cuomo, for example, is airing television ads attacking Trump while publicly ignoring his primary opponent, Cynthia Nixon, who is pushing him farther and farther to the left. Cuomo has called the GOP tax cuts a “missile” and a “dagger” aimed at the heart of the state. The state is also suing to overturn the law as unconstitutional.

Those are especially odd claims given that more than 80 percent of state taxpayers got a tax cut under the law, according to nonpartisan estimates. For the one-in-five who will pay the same taxes or more, the chief reason is that they can now deduct only $10,000 of their exorbitant state and local taxes.

If Cuomo and others had reacted to the federal tax law as they should have — by cutting New York taxes — 100 percent of state residents would be paying less.

But too many pols measure success by how much money government spends, not by how much of their own money working families get to keep. And by defying the national trend, Cuomo, Mayor de Blasio and city and state lawmakers are putting New York at a competitive disadvantage.

Don’t underestimate the modern Democrats’ willingness to double down on economic stupidity. If these new-school Dems actually cared about robust growth, they’d be much more like old-school Dems.