Back in the summer, when Fox’s Megyn Kelly confronted Donald Trump with a few of the nasty things he had said about women, he had a simple retort. “The big problem this country has is being politically correct,” he said.

Not economic growth, or terrorism, or war against the Islamic State. No, the big problem in these United States is political correctness.

Since that first debate, Trump and his fellow Republican presidential candidates have connected political correctness to virtually every issue: Vladimir Putin. Immigration. The San Bernardino shooting. Planned Parenthood. David Cameron. The Islamic State. Gun ownership. Social networks. Demagoguery. Muslims. Women in the military. Israel. American exceptionalism. Climate change. Education. The mental health system. The media. The national debt. Drug addiction. Prisoners of war. Women. Torture. Trans fats.

“Political correctness is killing people,” Ted Cruz said at last week’s debate.

Ben Carson warned of a conspiracy “to give away American values and principles for the sake of political correctness.”

The notion of political correctness became popular on college campuses a quarter-century ago but has recently grown into the mother of all straw men.

Once a pejorative term applied to liberals’ determination not to offend any ethnic or other identity group, it now is used lazily by some conservatives to label everything classified under “that with which I disagree.”

Republican candidates are using the “politically correct” label to shut down debate – exactly what conservatives complained politically correct liberals were doing in the first place.

When CNN’s John Berman last week asked Rick Santorum about Trump’s plan to ban Muslims from entering the country, Santorum employed the familiar evasive maneuver.

“Republicans are sick and tired of the political correctness that we can’t talk about this,” he said. “You can’t say the word ‘Muslim.’ ”

It wasn’t clear which officer in the P.C. Police told Santorum he couldn’t say “Muslim.” Presumably it was the same officer who provided New Jersey Gov. Chris Christie with this straw man:

“Some people believe that borders have become outdated,” he said. “They don’t believe in nation-states. They believe in a post-American world. … We have to speak out against it even when it becomes politically incorrect to do so.”

CNN’s Jake Tapper exposed the intellectual laziness in the label when Cruz said “political correctness” prevented U.S. officials from seeing radical Facebook postings by one of the San Bernardino shooters.

Tapper pointed out that the posting in question was under a pseudonym and was in a private message that the government can’t access. “How is that political correctness and not just privacy issues?” he asked.

Cruz changed the subject.

For Trump, the politically correct label has become a tic.

How does he explain his praise of Putin? “I’m not going to be politically correct.” How does he respond to the British prime minister’s criticism? “You want to be so politically correct all the time.” Does his anti-Muslim rhetoric radicalize more jihadists? “We can be politically correct, and I could say, ‘Oh well, no, there’s no problem.’ ”

He said there are “major problems” with having women in combat but the military is proceeding because “they want to be politically correct.” He defended profiling of Muslims by law enforcement and said anybody who disagrees “wants to be politically correct.”

If you don’t support his (false) allegation that thousands of New Jersey Muslims celebrated the World Trade Center collapse, Trump said, that is because “it might be not politically correct for you to talk about it.” Defending his plan to deport 11 million illegal immigrants, Trump warned that we will “become so politically correct as a country that we can’t even walk. We can’t think properly. We can’t do anything.”

The tic is contagious.

Marco Rubio thinks the “radical left” has found “a clever, politically correct way to advocate Israel’s destruction.”

Carly Fiorina alleges that “our government has become inept, sometimes because it is politically correct.”

Jeb Bush laments the “politically correct kind of curriculum.”

And Carson says of enhanced interrogation techniques, “There’s no such thing as political correctness when you’re fighting an enemy who wants to destroy you.”

Voters, told repeatedly that political correctness jeopardizes their way of life, are alarmed. “We’re tired of political correctness,” one Trump voter said in a focus group conducted by Frank Luntz for CBS. “I think we’re being burdened with it. I think it’s making us weaker as a country globally.”

He just doesn’t know what it is.

Dana Milbank is a columnist for The Washington Post. He can be contacted at:

danamilbank@washpost.com