Howard Polskin woke up the day after President Trump’s election with a powerful feeling that he had missed something important.

“I thought I was a smart guy, but I felt very dumb on Nov. 9, 2016,” he told me.

Polskin, a former journalist and then a public relations executive, realized that the way he was staying informed — sources including “the New York Times, Time magazine, the NBC News with Lester Holt” — may have been giving him the facts but they weren’t giving him a worldview shared by millions of Americas.

They were the millions who elected Trump.

Not long afterward, Polskin began a website and newsletter called TheRighting. The newsletter’s tagline: “Top News Headlines from the Far Right for the Rest of Us.”

For those who get their news from traditional, mainstream sources, it can be a five-day-a-week visit to another planet as it aggregates articles from right-wing sites and measures the audience of those sites.

“Because media is so bifurcated, I find it helpful to check in with the other media universe,” said one of the site’s regular readers, Daily Beast editor-at-large Molly Jong-Fast. “It’s weird how different the two worlds are.”

Weird indeed.

Take the demise of the Newseum, the recently shuttered Pennsylvania Avenue museum devoted to journalism.

If you became aware of its closing from mainstream sources, you might come away with one of these two ideas: It’s regrettable that an institution that celebrates the First Amendment had to close because of financial difficulties. Or: The place was foolishly overbuilt and unrealistic from the start, an exercise in hubris, though for a good cause. (You might even be ticked off that the Newseum store once sold “Fake News” souvenirs.)

If you happened to read TheRighting, you’d get a blast of something quite different.

The headline of an article from Communities Digital News was just the start: “Fake Newseum Closes Its Door. Trump Still President.” The article called the Newseum “a museum dedicated to elitist arrogance . . . an institution designed to promote the promoters of lies, Democratic Party disinformation and general leftist nonsense.”

You might not like it or agree with that — I certainly don’t — but it’s the hint of a pervasive worldview.

And that’s what Polskin had in mind. (He is, of course, not the first or the only one to do this work; some news organizations have reporters whose whole beat is covering right-wing media; and — among others — Will Sommer’s Right Richter newsletter has long been an important source of similar information.)

“I did this as a passion project,” said Polskin, who once covered network news from TV Guide’s New York bureau, and who worked at Sony and CNN before starting his own public relations company.

Not to make money (it doesn’t) but “to inform people in the center and on the left.”

In circulating the right-wing news, Polskin doesn’t try to fact-check or correct. And he understands there can be a downside since what he aggregates and shares may be racist, anti-science or flat-out false.

“I’m amplifying the message. I’m painfully aware of that,” he told me. He said he does draw a line — for example, he refuses to circulate stories from the Daily Stormer, the neo-Nazi website, despite their popularity and what they might say about the media ecosystem.

At the same time, he finds at least some of what he aggregates to be compellingly written and well argued.

In keeping track of the metrics of right-wing media, Polskin has noticed some overarching trends.

Most notable: the inexorable growth of Fox News’s digital operation, foxnews.com. Those who think of Fox’s influence as mostly from its television network, Polskin said, are missing a huge development.

Another: the rise in audience size and influence of the Washington Examiner, the conservative website and weekly printed magazine, founded in 2005 by billionaire Philip Anschutz and based in Washington.

On Friday, as mainstream news organizations grappled with the stunning news that an American airstrike had killed a top Iranian commander in Baghdad, the need for skepticism and caution needed to be top-of-mind for journalists and the public.

Not everyone remembered — or chose to recall — the media-driven rush to a disastrous war in Iraq more than 15 years ago.

TheRighting, though, was reflecting what many Americans were receiving from their information sources: pro-Trump cheerleading.

“Why Trump didn’t need congressional approval to kill Qasem Soleimani,” opined the headline of a Tom Rogan piece in the Examiner.

“Trump Was Right to Order Killing of Soleimani,” applauded Fox News. (“It will make America safer.”)

Polskin’s efforts have baffled his more liberal friends: “They think I’ve gone off the deep end.”

But he’s convinced — just as he was on Nov. 9, 2016 — that it’s important to understand how a sizable section of the country is forming its views.

“To be an educated person in America, you have to know what’s being said on the right.”

For more by Margaret Sullivan visit wapo.st/sullivan