Simon Moya-Smith is a citizen of the Oglala Lakota Nation and culture editor at Indian Country Today . Follow him on Twitter @Simonmoyasmith . The opinions expressed in this commentary are solely those of the author.

(CNN) I was sitting at home Friday when, in the background, I heard the ugly phrase leap out from the TV.

Democratic presidential front-runner Hillary Clinton was being interviewed on CNN's "The Lead" with Jake Tappe r when she used a blistering term rooted in racism against Native Americans to describe Donald Trump, the leading Republican presidential candidate.

"I have a lot of experience dealing with men who sometimes get off the reservation in the way they behave and how they speak," Clinton told Tapper.

Within hours, Clinton's political director, Amanda Renteria, took to Twitter saying Clinton "meant no disrespect to Native Americans."

"About the use of an expression today that has some very offensive roots. ... Divisive language has no place in our politics," Renteria tweeted.

But here's the problem with Renteria's words: The phrase has nothing but very offensive roots.

In the 19th century, the U.S. government forcibly confined Native Americans (who, according to a New York Times article at the time, were considered "shiftless, untameable ... a rampant and intractable enemy to civilization") into prison camps, known today as reservations. None were permitted to leave the boundaries without permission from their white captors.

This, folks, is called forced imprisonment.

In fact, Adolf Hitler was inspired by the American reservation system.

John Toland, author of "Adolf Hitler: The Definitive Biography," wrote that the tyrant and mass murderer thought the U.S. reservation system was a useful template for Jewish concentration camps.

"Hitler's concept of concentration camps as well as the practicality of genocide owed much, so he claimed, to his studies of English and United States history," wrote Toland. "He admired the camps for Boer prisoners in South Africa and for the Indians in the Wild West; and often praised to his inner circle the efficiency of America's extermination -- by starvation and uneven combat -- of the red savages who could not be tamed by captivity."

On Monday, Trump had a response to Clinton's "off the reservation" comment: "The Indians have gone wild" over her use of it.

"Now I won't even bring up the fact that the Indians have gone wild on that statement. You know that, OK. The Indians have said that that statement is a disastrous statement, and they want a retraction. I'm not going to get into that," Trump told CNN's Chris Cuomo on "New Day."

"Indians have gone wild," "Off the reservation." Are these two trying to make people frightened of Native Americans? Not likely.

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Frankly, I don't believe Clinton was being purposefully invidious to Native Americans. The piercing phrase is used far too frequently and heedlessly by Americans who have, what, forgotten what it refers to?

This is why Hillary Clinton's use of the word is so hurtful, no matter its intent: It is indicative of an America still frighteningly unfamiliar with the plight of indigenous peoples in this country.

Indeed, Cuomo told Trump he was unaware that anyone found the term "off the reservation" abhorrent, but he should be aware.

"As a historian, I would caution any of us in this country to talk about anybody being 'off the reservation,'" Nina Turner, former state senator and a supporter of Bernie Sanders, told Tapper later on his show.

"Let us not forget that the colonists of this country stole the land from our Native American brothers and sisters, and the government put them on reservations, so we have to be careful of that type of language as well. It's terrible," she said.

Tapper agreed. "A lot of people not aware of it, but the term 'off the reservation' -- very offensive to a lot of Native Americans," he said. Though he didn't call her out when she first said it, in his own remarks, Tapper appeared more in tune with Native Americans than Clinton.

What do the other candidates think?

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I reached out to Tara Houska, Native American adviser to the Bernie Sanders campaign. She told me Clinton's use of the term was just another example of "casual racism against Native Americans" in the United States.

"Whether it's a football team with a racial slur for its name, or a phrase used by a presidential candidate that speaks of the forced, deadly confinement of America's original peoples, we are regularly an afterthought," she said.

I reached out to the Trump, Cruz and Kasich camps, and so far their campaigns have not responded with a comment.

But Theodore Van Alst, a Lakota and assistant professor and co-chair of Native American studies at the University of Montana, explained that phrase is also cutting because "it makes us an historical oddity."

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"It perpetuates the idea that Native Americans reside only on reservations," he told me Monday, though today 7 out of 10 Native Americans live in metropolitan areas. "It also pins Native Americans down to a certain time and place ... it keeps native people from being contemporary."

Indeed, it is already problematic that so many people use the rotten term without a second thought. It is even more problematic when a leading presidential candidate uses it while claiming to be close with today's Native American communities.

Maybe get in closer, Madam Secretary?