(CNN) There are very few issues that Donald Trump loves to discuss as much as his campaign against "political correctness." Tapping into a set of arguments that grew out of the culture wars in the 1980s and 1990s, Trump has taken every opportunity possible to tell voters that he says what he thinks and refuses to be confined by what "liberals" agree to be acceptable. And while most of the political correctness debate has centered around college campuses, Trump applies this term to almost every issue. The pressure to be politically correct, in his mind, is the cancer that eats away at America.

The most recent incarnation of this rhetorical war came in the aftermath of the horrendous mass shooting in Orlando, when Trump condemned President Barack Obama and Hillary Clinton for both refusing to use the term "radical Islam." They were putting political correctness above national security, he said in his post-massacre address

On the face of it, Trump's bravado is a superficial part of the campaign. But the events in Orlando were actually a powerful reminder of why politicians and political activists who take language seriously have been doing much more than serving as "thought police." They have been engaged in a long struggle to fight against ugly, discriminatory cultural traditions that marginalize, ostracize and demonize entire social groups in ways that create a dangerous and toxic environment legitimating injustice.

The attacks on "political correctness" really took hold when the culture wars raged in the Age of Reagan. As historian Andrew Hartman argued in " A War for the Soul of America ," the early opponents of "political correctness" brought attention to institutions of higher learning, "which many people came to think of as leftist redoubts where standards were destroyed and the best of Western civilization had been replaced by a 'politically correct' mishmash of multicultural nonsense." The warriors against the politically correct were picking up on the strategy of British conservatives who in the mid-1980s called their opponents the "loony left" for a similar purpose.

President George H.W. Bush brought the term to political life in May 1991, at the University of Michigan, where he warned : "although the movement arises from the laudable desire to sweep away the debris of racism and sexism and hatred, it replaces old prejudices with new ones. It declared certain topics off-limits, certain expression off-limits, even certain gestures off-limits."

The attacks did not just come from the right. Comedian Bill Maher hosted a hit show, "Politically Incorrect," where the entire conceit was that hosts and guests would not be restrained in what they said. In January, agreeing to some degree with the presumptive Republican nominee, Maher warned that Donald Trump was a "result of a backlash to political correctness."

Opponents of political correctness love to find one ridiculous example of how this works, and then use that example to cast doubt on the legitimacy of huge swaths of activism.

But when Donald Trump goes after political correctness, he is restating opposition to something much bigger than the codes of discussion among college students. He is using the term to lash out against the powerful social movements that have challenged social, ethical, and cultural discrimination.

The decision to take language seriously took hold through the fierce political battles that have taken place since the 1960s, when activists recognized that language could be part of the arsenal used against social progress. For civil rights activists, it was crystal clear that the language used by white racists was extraordinarily damaging. An entire lexicon of racism went into the ongoing efforts to denigrate and dehumanize African-Americans. The term "n—ger" usually went hand in hand with the lynchings and the beatings of earlier eras.

Women have long understood that the demeaning words men have used to talk about the alleged weaknesses of females seeped into the way in which we thought as a society about what each gender could accomplish. Jews have been subjected to horrendous verbal assaults that have fueled stereotypes and propaganda that have been at the heart of anti-Semitism. The words used to describe gay Americans, such as "queer" and "fag" have played into a culture that made homosexuals seem outside of what the mainstream was. Women have faced rhetorical barrages that make them seem irrational, angry, and weak. And Native Americans have been subjected to constant stereotyping through words and images, which is why so many recoil when Trump uses the term "Pocahontas" to dismiss Sen. Elizabeth Warren.

The campaign to prevent racial and ethnic profiling has not just been some kind of misguided effort to be nice to all people at the expense of endangering the nation -- the goal is to uphold the civil liberties that define the country that we are trying to protect; to protect the rights of all citizens with the understanding that once we bring the barriers down for some groups, the rest will soon fall; and to prevent the kind of racial and ethnic stereotyping that has sometimes led some police officers to undertake lethal action against African-Americans.

And campus battles over what issues should be taught and discussed are not as trivial as opponents of political correctness make them out to be. Entire generations of writers and thinkers -- and even civilizations -- have been brought back into our intellectual conversation as a result of efforts to broaden the academic canon. Meanwhile, professors have been pushed to think more carefully about how they teach certain subjects so they can be aware of the biases sometimes inherent in their own training. And while sometimes these restrictions move in extreme and unproductive directions, often we have achieved great advances in our knowledge.

Trump's attacks on political correctness also ignore the very real strategic reasons behind certain choices that serious politicians make. The main reason that President Obama has avoided the terminology that Trump employs, for example, is his desire to keep the battle against terrorism focused on terrorist networks, rogue states and lone wolves who use religious ideology as a justification to murder. What he doesn't want to do is to turn this into a war against Islam.

President Obama's main concern is not about whether he is offending individuals but, rather, about describing the war in such a mistaken fashion that we provide our opponents with public relations material in a battle for hearts and minds. As President George W. Bush said on September 17, 2001, "The face of terror is not the true faith of Islam. That's not what Islam is all about. Islam is peace. These terrorists don't represent peace. They represent evil and war."

Yet Trump has elevated the attacks on political correctness to a new art form. In his use of the term, everything and everyone against him is written off as "politically correct." He has even abandoned the distinction that George H.W. Bush tried to make in Michigan. It is simply a catch-all to describe all of his opponents as people concerned with irrelevant issues. So, for example, if many Americans have serious problems with his proposal to ban all Muslims from the United States, they are somehow being politically correct.

Trump's opponents too often let these attacks slide, scared to be seen as proponents of the wrong side of the debate, usually ready to describe why something is not, in fact, politically correct rather than questioning the concept altogether. But this is a mistake. It is important not to allow these political battles to wipe away the many important gains that have been made in the struggle for social justice and risk undercutting efforts to build a stronger and more egalitarian America.