The Equal Employment Opportunity Commission, which enforces federal laws against workplace bias, explicitly cites comments like "go back to where you came from" as examples of "potentially unlawful conduct."

Similar phrases routinely show up in lawsuits that the EEOC files against employers alleging discrimination, harassment or retaliation based on race or national origin.

Apart from its legality in workplaces, Trump's language has ignited impassioned responses across racial, ethnic and political divides.

"It wasn't Racist!" tweeted Terrence Williams, a black comedian who supports Trump. "No matter what color you are YOU can go back home or move if you don't like America."

By contrast, Rachel Timoner, a senior rabbi at a Reform Jewish synagogue in Brooklyn, said such language would never be tolerated among members of her congregation.

"I'd want to sit down with them and ask them, where that's coming from?" she said. "If a person persistently degraded other human beings, I would need to say to them they could no longer participate. It's really important for us to create an environment where people of color and people of all identities feel welcome."

Facing an uproar from critics accusing him of racism, Trump has insisted that he wasn't being racist when he tweeted this week that the four Democratic members of Congress — all but one of them born in the United States — "originally came from countries whose governments are a complete and total catastrophe." Trump urged them to "go back and help fix the totally broken and crime infested places from which they came."

Rather, his message, the president explained the next day was: "If you hate our country, if you're not happy here, you can leave."

Yet Trump's exhortation for the four minority congresswomen to "go back" to their countries of origin, if uttered by an employee in a workplace, could constitute a firing offense or cause for a costly lawsuit.

Sam P. Israel, a New York lawyer who handles harassment cases, noted that plaintiffs usually must prove that an offensive comment wasn't made in isolation but as part of a broader hostile environment. If Trump were an employer facing a lawsuit, Israel said, there would arguably be enough examples to suggest a pattern of racially or ethnically disparaging remarks.

"All of those things are actionable if you have enough of them, and it could be illegal," Israel said. "The EEOC teaches that all of these things are bad and should be avoided, and the president is making a mockery of it."

In the aftermath of Trump's "go back" tweet, a suburban Chicago gas station clerk was fired after a video posted on social media appeared to show him telling Hispanic customers to "go back to their country."

Stephen Kalghorn, general counsel for the parent company of Bucky's Mobil gas station in Naperville, said the employee's comments couldn't be clearly heard on a surveillance video. But he was fired for engaging in a verbal confrontation with the customers.

Elizabeth Tippett, a professor at the University of Oregon School of Law, suggested that Trump's comments could make things worse for anyone who tried to echo him in a workplace. Tippett explained that the president's rhetoric would make it difficult to argue that a similar comment was made innocuously or out of ignorance of its racist connotations.

"When you have these cultural environments, you might see repeated comments from multiple people," she said. "The more frequent the comments are, the stronger the harassment claim."

Most Republican leaders have declined to characterize Trump's comments as racist. And a few supporters have parroted his remarks, including some at a Trump rally in North Carolina this week who chanted "send her back!" in reference to Rep. Ilhan Omar of Minnesota.

Donna Givens, an African-American neighborhood organizer who leads the Eastside Community Network in Detroit, said Trump's tweets were deeply hurtful.

"It immediately reminded me of being a child and being told to 'go back to Africa, (n-word)' — that got said to me repeatedly," she said. "My grandmother used to tell me to tell them to 'go back to their caves in Europe.' "

In light of the inflammatory rhetoric, "I don't think that we can pretend like the American workplace is a safe place for immigrants, for people of color or for women," Givens said. "The president has a bully pulpit. And the president sets the tone. And so there are people who feel justified in their hatreds now."

Andrew Pappas, a self-described conservative Republican who holds elective office in Anderson Township, Ohio, acknowledged that Trump's language, taken in a vacuum, was "not appropriate." Yet he expressed some understanding of it.

"I think that when you see Donald Trump react in a human way, it upsets a lot of people that are expecting maybe your true quintessential politician," Pappas said. "But it also resonates exponentially with the common American who says, 'You know what? I'd react that way, too.' "

The Rev. Tom Lambrecht, general manager of the conservative United Methodist magazine Good News, cautioned against any rush to declare certain forms of political rhetoric unacceptable

"The difficulty here is, who decides what is unacceptable?" Lambrecht said by email. "And how is that unacceptability enforced? Censorship?"

"At the same time," he added, "such despicable rhetoric is a teachable moment. It is incumbent upon Christians and others of good will to call out racism when we hear it in public debate or private conversation and to teach our children and grandchildren what is wrong with such attitudes."

Another pastor, E.W. Lucas of Friendship Baptist Church in Appomattox, Virginia, has firmly backed Trump, even posting sign outside the church declaring "America: Love or Leave It," explicitly echoing the president.

"People that feel hard about our president and want to down the president and down the country ... they ought to go over there and live in these other countries for a little while," Lucas told ABC 13 in Lynchburg.

Some advocates of free speech argued that censorship of political rhetoric should never be the solution, suggesting that there were better ways to combat it.

"Every American has the right to make up his or her own mind about what public officials say and how they say it —and if enough people disagree with a politician, they have the right make those opinions known in peaceful protest, or at the ballot box," said Robert Shibley, executive director of the Foundation for Individual Rights in Education. "Censorship of political speech only serves to rob citizens of the right to make up their own minds, which is fatal to a democratic society."

Chris Finan, executive director of the National Coalition Against Censorship, agreed that attempts to ban racist rhetoric "will never solve the problem."

Instead, Finan said, "It has to be challenged and refuted wherever it occurs."

Retired college football coach Bill Curry, who grew up in the segregated South, had some advice based on playing in the NFL under legends Vince Lombardi at Green Bay and Don Shula in Baltimore.

"One racist word out of your month and you were gone," said Curry, 76. "It didn't matter who you were. Period."

During college coaching stints at the University of Alabama and elsewhere, Curry followed the same policy.

"When you put down those rules like those great coaches did, it doesn't become a problem," he said. "You cannot let that racist thing get started. It will destroy unity, just like is going on in our country now."