When Minneapolis DFL Rep. Frank Hornstein rose on the Minnesota House floor in 2007 to ob­­ject when two critics of a smoking ban bill likened it to Nazism, I considered his point well-taken.

Suggesting that a ban on smoking in Minnesota restaurants is even remotely akin to the German political force responsible for the Holocaust is a repugnant overreach. It trivializes the 20th century's most shameful episode and the wounds of those touched by the genocide of 11 million people, 6 million of them Jews.

That would include Hornstein. All four of his grandparents died at Nazi hands. His mother and father were escapees from German forced-labor camps who eventually made their way to Cincinnati, where he was born in 1959.

I sympathized again a few years later when, on these pages, Hornstein told readers about the sting he feels when Nazi analogies arise during routine legislative debates. He cited quite a litany: The state's teachers' union had been called the "teacher's Gestapo." A light-rail construction zone was said to include "concentration-camp fencing." Oil-bearing freight trains were likened to "the train from Auschwitz."

Hornstein's grandmother died at Auschwitz. So did a million other Jews. Flippant references diminish the enormity of that crime, he wrote two years ago.

Thus when politicians, pundits and people I ran into at the grocery store lately took to comparing Donald Trump to Adolf Hitler and the nativist bent of the 2016 Republican Party to the 1930s-era National Socialist German Workers Party, I wondered: What would Hornstein say?

"I won't say 'Don't go there,' " he replied. "But know what you're talking about if you do. … Trump is in a different category than a smoking ban."

Indeed he is. The front-runner in national GOP presidential polls has called for the deportation of an estimated 11 million undocumented immigrants; denial of entry to the U.S. for all Muslims, regardless of their citizenship; and a database/watch list/surveillance system (his comments have meandered) for either Syrian refugees or Muslims generally. In response to November's ISIL attack in Paris, he suggested closing some mosques in the United States.

Trump is peddling the notion that America can only be great again if "those people" can be contained, controlled and/or removed. An echo of fascism isn't hard to hear in that message, as plenty of commentators have already observed. The Philadelphia Daily News went so far on Dec. 8 as to make Trump its cover boy with the double-entendre caption "The New Furor."

Does Hornstein hear the echo, too?

"Trump is using dangerous, frightening rhetoric. He needs to be responded to," Hornstein said. "But we are not Weimar Germany," the German government of the 1920s and early '30s. "We are not a nation reeling from defeat in a major war and humiliated by the Treaty of Versailles. Our democratic institutions are strong.

"Trump is giving this nation a teachable moment."

Hornstein aims to do some of that teaching himself. He's a newly appointed senior fellow at Augsburg College's Sabo Center for Democracy and Citizenship (aptly named for former U.S. Rep. Martin Sabo, Augsburg '59). His assignment there is right on point. He's examining how the Holocaust affects contemporary political discourse, with the goal of completing a book on the subject.

Don't expect a scolding screed about politically correct speech. Hornstein is too thoughtful for that — and too realistic. He was a community organizer and Met Council member before election to the state House in 2002, so one might say that political debate has been his life's work. He has learned, likely to his regret, that informing others that their words give offense seldom silences them.

I expect him instead to make a "boy who cried wolf" argument: Overuse of Nazi analogies is rendering them ineffective in American political debate — even when they might be apt. His point is akin to a circa-1990 observation by attorney and author Mike Godwin, known as Godwin's Law: "As an online discussion continues, the probability of a reference or comparison to Hilter or Nazis approaches 1."

Hornstein put it this way: "If everyone is Hitler, who is Hitler really? When you go right to a Hitler analogy, you've already lost the argument. You've cheapened the debate."

Instead, he counsels, those who would counter Trump and others practicing the politics of exclusion would do better to draw from American, not European, history. Xenophobia and even genocide have a long, dark history in the United States, he notes. They've seldom carried the day politically. When they have, they have become points of national shame, not pride.

The internment of Japanese-Americans in 1942, the Chinese Exclusion Act of 1882, and — he didn't mention it, but I will — the Minnesota expulsion of the Dakota people in 1862 are recounted today as cautionary tales. They are episodes that diminished a nation that draws its unity not from race or religion, but from devotion to the shared idea that all are created equal and possess an inalienable right to join in self-governance.

But what matters most in coming months as the nation settles on its major-party presidential candidates is not whether or how history is invoked, Hornstein said. It's whether Americans of good will find ways to vigorously and vocally reject hatred of Muslims or any other group maligned because of race, religion or national origin.

"That is ultimately the lesson that the Holocaust teaches us — that we must respond in the most assertive ways possible to racism, xenophobia and bigotry. We need to make it our highest priority to confront those things," he said.

One doesn't need to invoke Hitler, the Holocaust or any other history lesson to make that point. One doesn't need to be partisan either. All one needs is a poster, a marker and some tape for a sign like the one that appeared last month on the door at Common Roots Cafe in Minneapolis. "Hate has no business here," it read. "We stand with our Muslim community members. We stand with refugees and immigrants in our community. All are welcome here."

Get busy with those markers. Minnesota's precinct caucuses are set for March 1, less than two months away.

Lori Sturdevant, an editorial writer and columnist, is at lsturdevant@startribune.com.