The stigmatizing of The Other is with us always.

Some people think the never-ending American immigration debate is mainly about the so-called dreamers, the undocumented, illegal aliens who slipped into America as babies, the ones President Donald Trump would deport to countries they’ve never known.

Those who imagine their own lives immune to such cruelty have forgotten some important history — of their own families.

The debate also is about Jews. And Muslims and Irish and Italians, too, and all those millions whose skin color further enflames the issue.

On my telephone now is some bigmouth whose voice carries an unmistakable sneer.

“You like these immigrants so much,” he says, “why don’t you hide some of them in your house? You got any of these people living in your house?”

“No,” I tell him, “but I’ve got their photographs hanging in my living room. I don’t call them immigrants. I call them my grandparents.”

The dreamers are just the latest roll call of newcomers, the newest generation that always gropes its way into an America that officially welcomes them but unofficially gives them a pretty rough time.

Witness Trump’s recent State of the Union speech. He mentioned immigrants but immediately went right to “drugs and gangs. … They have caused the loss of many innocent lives.”

He thereby willfully ignored a few salient facts offered by his own Department of Justice: that 13 percent of the U.S. population is foreign-born, but only 5 percent of the inmates in all U.S. prisons are foreign-born.

The stigmatizing of The Other is with us always.

When Martin O’Malley was mayor of Baltimore, he kept a sign on a wall above his City Hall desk. It said, “No Irish Need Apply.”

The sign was a reminder of the familiar American rejection slip that once appeared in countless businesses, announcing to the Irish that they weren’t wanted, and signifying to everyone else there was something different about these people, something to be shunned.

“Nobody wanted us,” O’Malley would explain to anyone who wondered why he held onto the sign.

Then we have Nancy Pelosi, minority leader of the House of Representatives. Originally, she comes off of Albemarle Street in Baltimore’s Little Italy. At a meeting of the U.S. Conference of Mayors, she said Trump’s plan to evict the dreamers is “a campaign to make America white again.”

She knows such things because she remembers a time when Italians were the outsiders — until her father, Tommy D’Alesandro Jr., a child of immigrants who became mayor of Baltimore, helped change such ignorance.

Immigrants are hungrier than anyone to take part in the American journey, to feel the country’s good-natured embrace.

You want evidence? I’ll give you my best example. It’s three days after the terrorist attacks of Sept. 11, 2001. I’m in downtown New York, watching a brown-skinned man nail a piece of paper into a tree at Union Square, a short walk from the disaster.

The paper is headed, “Open Letter to a Terrorist.” It says, “Well, you hit the World Trade Center, but you missed America. You hit the Pentagon, but you missed America.

“Why? Because America isn’t about a building, or financial centers, or a military. America isn’t about a place. America isn’t even about a bunch of bodies. America is about an idea. We don’t live in America. America lives in us.”

Nearby, I met a man named Dominic Mree, an immigrant from Tibet.

“I was walking on Church Street [near the devastation],” Mree said. “I could feel the heat. People were running. I saw a woman stop on the corner to cry. I ran to her. She said, ‘My pride has been destroyed. My city of the world is destroyed.’ She was crying, crying.”

“What did you do?” I asked.

“I started crying, too,” he said.

He managed a store on Canal Street, where he’d proudly hung an American flag. People walking past asked how much he wanted for it. Mree shook his head. His flag was not for sale. He was from Tibet, but America was his country now. Not just the place, but the idea. It lived inside him.

A former Baltimore Sun columnist and WJZ-TV commentator, Michael Olesker is the author of six books. His most recent, “Front Stoops in the Fifties: Baltimore Legends Come of Age,” has just been re-issued in paperback by the Johns Hopkins University Press.