Following the Dec. 2, San Bernardino attack that killed 14 people and injured 21, Republican presidential candidate Donald Trump says political correctness is causing problems in America. (Reuters)

Donald Trump’s excuse for his latest offensive idea, to ban all Muslims from the country, is the same one he used when he insulted Mexican immigrants, women, and prisoners of war: People are just being too “politically correct.”

“I wrote something today that I think is very, very salient, very important and probably not politically correct, but I don’t care,” he told supporters at his rally in South Carolina on Monday night after releasing a policy statement about barring an entire religious group.

In a nation where people often use language carelessly, the term politically correct is usually wielded very strategically.

Often it’s used as a put-down, a way to brush off the offended person as being overly sensitive. So while Trump is asserting his right to free speech, he is at the same time calling into question the listener’s right to complain about what he’s saying.

“It’s a verbal jiu-jitsu,” said Derald Sue, a psychology professor at Columbia University. “When you say, ‘I have no time to be politically correct’ what you are doing is turning the tables on the person raising a legitimate issue. You detract away from the issue that is being presented. You make the person the problem.”

It’s not exactly an invitation to open dialogue.

Republican presidential candidate Donald Trump wants to stop all Muslims from coming into the United States. Here's what he has said about Muslims since 2011. (Sarah Parnass/The Washington Post)

Throughout its history, the term politically correct, or P.C., has been politically loaded. It became mainstream in the U.S. in the 1990s with the rise of backlash against identity politics, but there were earlier references to it in the 1970s around the feminist movement, though the usage then was more sarcastic.

William Safire, in a 1991 New York Times column, deconstructed the term: “The phrase began as an assertion by liberal (progressive, concerned) activists and then was turned into an attack phrase by conservative (right-wing, heartless) passivists.”

That same year, President George H.W. Bush, in his commencement speech at the University of Michigan, used the term to describe an assault on free speech.

“The notion of political correctness has ignited controversy across the land,” he said. “And although the movement arises from the laudable desire to sweep away the debris of racism and sexism and hatred, it replaces old prejudice with new ones. It declares certain topics off-limits, certain expressions off-limits, even certain gestures off-limits.”

That sentiment has been festering within the political right for almost three decades. Those who share Bush’s view say Trump’s use of the term is tapping into a deeper public gripe that language is policed by a liberal elite. Even some conservatives who disagree with the substance of Trump’s speech, will evoke the famous quote from a biography of Voltaire, “I disapprove of what you say, but I will defend to the death your right to say it.” Others find refreshing his ability to speak freely without consequence.

There is a certain irony then that some, like Trump, use the term politically correct to actually stifle speech. It tells the offended person or group that they have no right to express their feelings, shutting down any further discussion and putting them immediately on the defensive.

“I think with political correctness, in the world of Donald Trump it’s used to bully people out,” said Peter Smagorinsky, University of Georgia language professor.

And, while the anti-political correctness rhetoric is nothing new in GOP politics, Trump’s cavalier attitude toward blatantly hateful speech has intensified it.

“Trump’s use of the term allows [people] to be Trumpish in the way they say this nasty discriminatory stuff,” he said.

A review of every Trump tweet and retweet since he announced his run for president in June illustrates this point:

“So many “politically correct” fools in our country. We have to all get back to work and stop wasting time and energy on nonsense!” he tweeted on August 8. It was retweeted 12,205 times.

In June, he retweeted one fan who wrote, “wish there were more people in the public eye with this attitude. It’s only way 2 defeat political correctness.” And another in July who wrote, “Glad U R Man Enough 2 Speak the Truth in this Pathetic Politically Correct World.”

Matthew Woessner, a political science professor at Penn State University, Harrisburg, is among those who believe that people, especially on college campuses, have taken concerns over offensive language to an extreme. But he also thinks Trump has co-opted the term politically correct to make sweeping, dishonest statements he can’t otherwise defend.

Woessner said all too often people on the left will label someone a racist or sexist who makes “a nuanced and respectable policy argument.” But he said on the right people are too quick to label criticisms as political correctness.

“We have to get away from labeling the opposition and get to the substance,” he said. “[Trump] is damaging our political discourse, rather than defending on merits, he thinks [attacking political correctness] will give him a free pass.

In October, the University of Wisconsin Milwaukee’s Inclusive Excellence Center, which advocates for intercultural sensitivity, added “political correctness” to a list of words discouraged on campus. It described the word as a “microaggression” because it’s dismissive of people’s feelings about what they find insulting or degrading.

But Harold Takooshian, a psychology professor at Fordham University, argues that it’s “un-American to be offended.”

“There should be nothing politically correct, there is no correctness,” he said. “Using that as a criticism (Trump) is tapping into our cultural history.”

Takooshian noted that one of the earliest uses of the term “politically correct”  was in Communism and referred to the “correct” party positions. This definition, he says is counter to the American values that entitle everyone to voice their own beliefs, regardless of how mean-spirited.

“People who charge ‘PC’ are saying they are entitled to express whatever they are thinking with no fear of punishment,” he said. “I think this explains why even people who dislike Donald Trump support his most outlandish comments, because they revel in his exercise of the American value of free speech.”

The paradox is that when those who are offended by Trump continue to push back and express outrage, they boost his support by giving credence to his claim that First Amendment rights are at stake.

“In that way, the use of the term “political correctness” provokes a response that makes it seem as if people like Donald Trump are actually being courageous with their words,” Meg Mott, professor of politics at Marlboro College in Vermont, said. “They aren’t.”