Jay Parini, a poet and novelist, teaches at Middlebury College in Vermont. His most recent book is " The Way of Jesus: Living a Spiritual and Ethical Life ." The opinions expressed in this commentary are solely those of the author.

(CNN) This morning I watched the viral video from the Fresh Kitchen deli in Manhattan , where a man is seen confronting staff and customers because he heard some diners speaking Spanish and the staff responding in Spanish.

The man yells: "Your staff is speaking Spanish to customers when they should be speaking English." He points a white cellphone at the Spanish speakers. "Every person I listen to: He spoke it, he spoke it, she's speaking it. This is America!" he says. He threatens to call immigration enforcement authorities.

One has to give it to the person who replies in the background: "Yeah, this is America. So ignorant."

It's true, this man's ignorance is palpable. It's also true that he's not the first American to express this idea, or think it privately. Over the years, we've all heard it one time or another: "Speak English, damn it!" It's safe to say that, even though the man at the deli expressed the thought in such a painfully obvious, rude and public way, millions of his fellow Americans feel pretty much the same way as he does -- and some show it occasionally with their votes.

They are wrong, in my view, but are they "bad people?" Of course not. They are our fellow Americans.

They might well be motivated by pride in their country, and be conflating speaking English with being patriotic. They may well live in parts of the country where only rarely are languages other than English heard in the streets.

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They may feel that not speaking English is a sign that newcomers don't respect them or their culture or American values. They may well feel threatened. Fearful. If you don't share my language, what else about my life don't you share?

But this is a confused view.

The reality of American life, with our complex polyglot culture, is actually deeply reassuring.

The fact is, the man in the video appears to be dwelling, like so many others these days, in the United States of Amnesia (as Gore Vidal once called this country) -- a place where history is often lost. The most obvious truth about us is that we really are -- despite all cries to the contrary -- a nation of immigrants, by immigrants, and for immigrants. This is our reason for being.

When people first come here, it is not at all unusual for them to speak -- at first -- mainly the language of the land from whence they came.

Beyond this, the United States has a deep polylingual history.

Taking it from the top, for centuries countless indigenous languages were spoken in North America, from the Eskimo-Aleut languages of Alaska and the Northwest Territories through the endless dialects of various Native American linguistic groups, including branches related to the Aztecs, Apaches, Iroquois, Algonquian, and Sioux nations. And this is just the tip of our vast linguistic iceberg.

Beginning with the conquest of the New World by Columbus, the Americas became a Spanish-language culture in vast territories to the south and southwest. Ponce de León arrived in what is now the United States in 1513. Indeed, Florida itself was Spanish until the early nineteenth century. In more recent decades, immigrants from Cuba, Argentina and other Latin American countries have made it home. (And if you are in Miami, it wouldn't hurt you to know some Spanish.)

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Texas, California, and much of the American southwest were Mexican territory until the mid-nineteenth century: that is, the Mexicans were here before us.

And in New Orleans and parts of Louisiana, the dominant language was French before it was English, although New Orleans was for a period under Spanish control in the late eighteenth century.

The Dutch, of course, began to colonize North America with the establishment of trading posts in New York as early as 1613. They spoke Dutch. When German immigrants poured into Pennsylvania in the late seventeenth century, the German language took root and spread westward; one Virginia county petitioned Congress to print federal laws in German as well as English, to aid farmers who spoke only German.

There is no question: although English has always been front and center because of British occupation that began with the Jamestown Colony and then the Plymouth Colony, immigration has played a huge role in the demographic and linguistic patterns of the United States.

And, it should be firmly noted, the United States has no official language.

Only willful ignorance leads people to believe that English must be or should be spoken here.

I know of what I speak: My own family spoke Italian for many years, in fact, having come to this country from northern Italy with the vast Italian immigration of that era. Indeed, by 1920, over four million Italians had come to the United States, bringing with them a wonderful language that I still regard as a family treasure.

The vast waves of Asian immigrants, too, going back to the arrival of Filipinos in the 1830s as laborers in California, and later Chinese, Japanese, Korean and Hawaiian immigrants (pre-statehood, of course) , brought their invaluable contributions to the American experiment -- and their languages, which, like those of most immigrant groups, linger within their family culture for a generation or two.

We are, indeed, a patchwork quilt of many nations, many languages. Our great national strength is the richly layered culture that has emerged from this vivid fact of our founding. We get energy and hard work from our immigrants, and we should do everything we can to see that we don't ward off newcomers from anywhere. They are the lifeblood of our nation. They always will be.

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They will learn English soon enough. They will have to -- leave them alone about it.

It's sad that our current President, Donald Trump, appears so woefully ignorant of this history, and because of this gives new "permission" to people like the deli guy to nurture and display such an ugly strain of American thought.

Only this past week, at a meeting attended by reporters in which the President discussed Mexican immigration and gangs, he said: "We have people coming into the country, or trying to come in -- and we're stopping a lot of them -- but we're taking people out of the country." He added : "You wouldn't believe how bad these people are. These aren't people. These are animals." We hope he was referring only to violent gangs, but after years of less ambiguous, and bigoted, pronouncements, America can no longer tell.

Indeed, so much of what this President has done, in domestic and foreign policy, appears to have its roots in a deep hatred of foreigners, people who are "not Americans," these "animals" coming from "***hole countries" across our sacred borders. It's a terrible signal to send.

Trump and the gentleman screaming about Spanish-speaking Americans at the Fresh Kitchen in New York City -- the original melting pot! -- should be sent back to school and given a history lesson.

Let us hope the formal complaint filed with the state court disciplinary system about this man (who is a lawyer, it turns out), as well as the petitions and other public censure he has earned for his ignorance and chutzpah -- including a New York Daily News front page excoriating him -- delivers a (figurative) smack to the head that wakes him to reality.

Editor's note: This story has been updated from an earlier version to include reference to the Jamestown colony and clarify a reference to Hawaiians as migrant laborers, pre-Hawaiian statehood, in 19th century California.