It’s possible for a person to be ignorant. We all are, sometimes. And anyone who has lived in Donald Trump’s America knows what a pig looks like — “a greedy, dirty or unpleasant person” can be found in the White House.

This week, we’re reminded that it’s possible for the Trump administration’s immigration policy to be both piggish and ignorant. Call it pig-ignorant, or “extremely stupid or uneducated,” per Oxford English Dictionary..

One refers, of course, to the administration’s new guidelines for granting green cards denoting permanent residency status to legal — yes, legal — immigrants. If a legal immigrant has the temerity to use government services — sign up for Medicaid, for example, or get hurt on the job and claim disability benefits — no green card for you.

You can’t make this up

Incredibly, the administration would even use credit scores and other measures to screen out people who might use services later.

The president with thousands of lawsuits, mostly over unpaid bills, President Tax Fraud, President Trump University, the man who went broke running casinos and has doubled the federal deficit from 2015 levels, wants to see immigrants’ credit reports.

And stand in — stop laughing — judgment.

“Give me your tired and your poor who can stand on their own two feet and who will not become a public charge,’ said Trump’s acting director Immigration and Customs Services Ken Cuccinelli said, butchering the famous poem inscribed on the Statue of Liberty, remaking it as accountants might.

Piggish this is, but this is an economics column, so let’s talk about why this is also profoundly economically ignorant. By happy coincidence, Goldman Sachs just released a report on the economics of immigration, one easy enough for even Cuccinelli to understand.

The first thing an economy needs to grow is population growth — and, in the United States and the developed world, most potential population growth comes from immigration. The formula, roughly, is that a developed nation can grow by about the sum of its percentage growth in working-age population and productivity. It’s really, truly, not complicated.

“Long-term sustainable economic growth in any nation is linked to a growing and appropriately skilled labor force,” Goldman strategist Abby Joseph Cohen writes.

Immigrants provide growth

“Slowing labor force growth is a challenge faced by many nations,” she continues. “The United States has been a notable exception among the world’s largest economies. Since 1990, the U.S. labor force has grown by almost 30% and immigrants have accounted for about half of this net increase.”

And that’s the most-important reason why the U.S. consistently grows faster than aging economic rivals in other mature economies, notably in western Europe and Japan, Cohen says.

Labor-force growth is essential to the tax revenue base, especially in aging nations, Cohen adds. In the United States, the ratio of workers who pay Social Security taxes to benefit recipients was 3.3 in 2005, and fell to 2.7 in 2018, en route to 2.0 by 2035.

“With a decreasing birthrate and an aging native population, the potential importance of immigration to the future growth of the U.S. labor force and its economy is expected to increase,” she adds.

In other words, if you want your Social Security to be there, the smartest path is to admit young workers to pay for it. Cohen would focus on richer ones, but America is more than economics.

It’s terrific that tech companies have been founded and fostered by immigrants or their children, from AAPL, +3.75% Steve Jobs’ birth father was Syrian) to Intel INTC, +1.58% (Andy Grove was a Hungarian refugee who likely wouldn’t have passed the means tests that Trump would impose), and it’s just as cool that teachers and soldiers are children of Mexican migrants.

In a few years, their kids will start companies.

Those are the economics of immigration — Trump’s position is no more or less ignorant than clinging to supply-side economics, coal, or protectionism.

The morals of pigs

Now let’s talk about moral piggishness.

First, Trump’s long-standing claim that he’s only against illegal immigration is laid bare now, even more than before. Just one of his now 12,000-plus lies in office. Second, Cuccinelli’s argument that he’s living up to the motto on the Statue of Liberty because that legendary inscription was only meant to describe people from class-stratified European countries is simply disgusting.

Un-American. And false.

Cuccinelli’s an Italian-American born in New Jersey, near where I grew up, and should know better. My Irish aunties told my cousin not to marry an Italian guy because they all cheat, and a sleeveless undershirt was a “guinea T” to one and all.

People talked about Italians as crass, or worse, as casually as discussing weather. Maybe folks in Edison were too polite to say this to the Cuccinellis.

In Jersey.

In the ‘70s.

Sure.

The hometown he left as a toddler is nearly half-Indian now — India is a big, not-in-Europe country, with a caste system way more rigid than Europe’s.

So maybe Cuccinelli, for whom grasping the history of Edison, N.J., is too tall an order, is too dense, or too focused on skin color, to grasp that Indians, Mexicans and Hondurans are simply writing the latest chapter of the American story we all grew up on.

Rather like the president he serves.