This is a column about 42 percent of Republicans. It is also a column about trust.

A few days ago in Miami, the Knight Foundation, a philanthropic institution, convened a conference of journalists, tech persons, business persons and others to consider the state and future of journalism. Central to the gathering was a study conducted by Gallup and Knight measuring American attitudes toward news media.

As medicine, it was castor oil.

Among its findings: More Americans (43 percent) have a negative view of media than have a positive view (33 percent); 66 percent say media do a poor job of separating fact from opinion; 58 percent say it is harder to be well informed today because there are so many news sources available; asked to score news media on a zero-to-100 scale with 100 representing maximum trust, Americans gave news media an anemic 37.

But there was one finding that leapt out at me: Four out of 10 Republicans said they always regard as “fake news” accurate news stories that cast a favored politician or group in a negative light.

Let that marinate for a moment. They concede it to be true, but they regard it as “fake” if they don’t like what it says.

As it happens, this conference unfolded in a state and nation still reeling from our most recent gun massacre: 17 people killed at Marjory Stoneman Douglas High in Parkland. Students who survived this latest mass casualty event have emerged as angry and forceful advocates for gun sense to replace the nonsense of current laws that allowed a disaffected 19-year-old to get his hands on an AR-15 rifle and mow people down at random.

With their unquestionable moral authority, these kids gave some of us the sense they might just be able to move the needle on gun-control legislation. Conservatives must have felt the same way. Which is why some of them began claiming the butchery never happened. These kids, they said, are so-called “crisis actors,” trained to simulate tragedy in order to embarrass the NRA and embolden gun-control activists.

It is an absurd and offensive theory. We’ve heard it before, though — heard it after Sandy Hook, heard it after Las Vegas. Why wouldn’t we hear it, if 42 percent of Republicans — notwithstanding that it is crazy — are ready to believe it?

I am willing, even eager, to have the discussion about what news media must do to earn back the public’s trust. Let’s talk about ways to keep cultural, class, racial and political biases out of our reportage. Let’s figure out how to protect ourselves from attack by trolls. Let’s consider strategies to more effectively wall off opinion from hard news. Let’s ask if we need so much opinion to begin with.

But let’s also talk about what’s going on with 42 percent of Republicans. Because clearly, 42 percent of Republicans are out of their damn minds. For the record, 17 percent of Democrats are, too.

And 100 percent of everybody else should recognize this as a clear and present danger. It is bad enough that malevolent online hoaxers make it difficult to tell the difference between fact and fiction, but when you no longer care about discerning that difference, when truth matters less to you than protecting your political turf, you are a virus in the body politic of a democratic nation. You are an infection that threatens the ability of free people to understand their world and make competent decisions about it.

So let me be real clear here. As a journalist — as an American — I am not interested in earning those people’s trust.

Frankly, they should be asking what they must do to earn mine.

Leonard Pitts is a columnist for The Miami Herald.