President Trump speaks during a news conference on Thursday at the White House in Washington. (Nicholas Kamm/Agence France-Presse via Getty Images)

In his remarkable news conference yesterday, President Trump received scrutiny on his claim to have secured “the biggest electoral college win since Ronald Reagan.” When a reporter pointed out that this claim was very easily disproved and raised issues of trust, Trump responded, “Well, I don’t know, I was given that information. I was given — I actually, I’ve seen that information around.”

Later in this rambling affair, Trump showed greater command of programming values on the 10 p.m. hour of CNN. “You look at your show that goes on at 10:00 p.m. in the evening,” said Trump in response to a question from CNN correspondent Jim Acosta. “You just take a look at that show. That is a constant hit. The panel is almost always exclusive anti-Trump. The good news is he doesn’t have good ratings. But the panel is almost exclusive anti-Trump and the hatred and venom coming from his mouth. The hatred coming from other people on your network.”

Little command of basic facts, excessive command of cable news tendencies — they both descend from the same problem, which is that … Trump watches too much cable news. We’ve known this for some time, of course. On the campaign trail, Trump would commonly cite his misgivings with cable-news coverage. At one point, he claimed to be boycotting Fox News, though he later admitted to Megyn Kelly that this dramatic declaration was pretty much a fraud. As president, Trump has quite patently gathered his cues from cable shows, and the evidence surfaces in his Twitter account. Analysts have taken to tracing the substance of his tweets to programming moments on CNN or Fox News.

That outburst was tethered to a segment on “Fox & Friends First.” Makes sense, considering that Trump has repeatedly praised the “Fox & Friends” franchise, including at yesterday’s news conference: “It’s the most honest,” he said. Anyone inclined toward placidity regarding the Trump administration might pause to consider that “Fox & Friends” allowed Trump to claim that Ted Cruz’s father was involved in the JFK assassination. It also smeared former president Barack Obama on numerous occasions — once falsely suggesting that he was engaged in silliness while dissing Israeli Prime Minister Benjamin Netanyahu, and at other points vastly inflating the unemployment rate and falsely claiming that Obama had offered to donate to the International Museum of Muslim Cultures “out of his own pocket.”

Even as “Fox & Friends” was racking up all those embarrassments, it was hosting Trump-the-mogul on its show with weekly call-in segments, a crucial point in contextualizing the president’s fondness for the program. For other morning fare, he also watches MSNBC’s “Morning Joe” and, apparently, CNN’s “New Day”:

That was false, petty, unpresidential and depressing.

Yet we already knew that the president was petty and easily distracted. What’s more concerning about his cable news appetite is how it will ill-prepare him for the job that lies ahead. Here are three reasons to worry:

1) Cable news is slow. Last month, photographers swarmed Trump as he sat aboard Air Force One. Video of the event captured an ad coming from the television. “800-588-2300 EMPIRE,” went the jingle from the set in the room. Though the channel was not visible in the video (see below), cable-news viewers know Empire Carpet.

Empire surely enjoys hearing its jingle at such exalted levels. But the idea of the president of the United States, whose time is his greatest resource, sitting around for commercial breaks grinds against the informational imperatives of the modern presidency. Over the course of its hour on Wednesday night, the Fox News program “Hannity” churned out about 7,000 words, on the media, on Flynn, on Russia — pretty much the same subjects as CNN that night. That count, mind you, includes not only the analysis from host Sean Hannity and Piers Morgan and company, but also the standard chatty cable news folderol, like this:

By the way, two good nights in a row, that’s pretty good. Even if you dislike me and you have something to say, the hot number is right there on your screen, 877-225-8587. And we hope you’ll give us a call and let us know what you think of the show.

That’s all the time we have left this evening. Quick programming note, tomorrow night, 10:00 eastern, I will be in Washington D.C. to interview the Israeli prime minister, Benjamin Netanyahu. That’s tomorrow night at 10:00. Thanks for being with us. We’ll see you form Washington tomorrow.

Broadcasters commonly move at a rate of 160 words per minute. A “high level exec”? Five hundred seventy-five words per minute. Put aside all the stupidity, lying and other nonsense on cable news: Even if this medium were a lean delivery machine for news and analysis, it’s not even close to the most efficient approach to becoming informed.

Obama appeared to understand these pitfalls. “He reads a lot of longform journalism,” said then-aide Dan Pfeiffer back in 2014, according to a report by Jeremy Barr. “Where he does not consume a lot of media is on television,” said Pfeiffer, though the president always did somehow have a notion of how Fox News was covering things.

As The Post’s Marc Fisher wrote during the campaign, Trump has never been a reader and was unlikely to change once in the White House. “I never have. I’m always busy doing a lot. Now I’m more busy, I guess, than ever before,” said then-candidate Trump to Fisher. That said, in his pre-presidential life, Trump reviewed news clippings about himself, a practice that appears to have transitioned into the White House. “He often has to wait until the end of the workday before grinding through news clips with Mr. Spicer, marking the ones he does not like with a big arrow in black Sharpie,” reported the New York Times.

White House Deputy Communications Director Raj Shah cites yesterday’s news conference as proof that Trump pulls information from both television news and from print sources. During the session, the president critiqued not only Don Lemon but also a report from the Wall Street Journal. Last week, too, he complained on Twitter about a story that appeared to have run in the print edition of the New York Times. Any notion that cable news constitutes the “sole or primary source of his news, briefings or education/background on policy, national security matters, etc.” would be “completely false,” notes Shah in an email. Nor is it accurate to conclude that the president is reading only the stuff he critiques, Shah contends.

2) Cable news is repetitive. Though cable news networks are generally wealthy operations, they do not use their resources to cycle through hundreds of different stories each hour. That approach wouldn’t rate well.

Instead, the best bet is to stick with a few stories that score high on the public-interest scale — and keep playing them over and over, with an accent on updates and an ever-rotating roster of analysts and panel discussions. These days, that means Trump, Trump and more Trump. Just take a look at how “CNN Tonight” — the show of Trump fave Don Lemon — approached the news menu over recent days. On Wednesday night, Lemon’s show in the 10 p.m. hour addressed the still-developing news regarding former national security adviser Michael Flynn, the withdrawal of labor secretary nominee Andrew Puzder and the White House’s policy toward Israel. Earlier in the week, it covered the Flynn crisis plus allegations about contacts between Trump campaign officials and Russian officials.

There’s no criticism here of CNN for pursuing limited topics. Those were, and continue to be, compelling news stories.

But: Do they prepare a president for what’s coming tomorrow? The federal government is a sprawling and sloppy beast covering every facet of American life. Go ahead and try counting the number of U.S. government agencies. Though few of them require the attention of the president at any given time, cable news is not the place to secure a broad-ranging understanding of the job.

“It’s not our job to brief the president,” says a cable industry executive.

Another knock against presidential cable programming is that it goes heavy on what just happened, instead of issue-based coverage of what may be coming up the pike. It’s this aspect of consuming television news that Trump appears to enjoy, for it gives him a chance to nitpick people over things that he himself has experienced. As he said yesterday: “Here’s the thing. The public is — you know, they read newspapers, they see television, they watch,” said Trump. “They don’t know if it’s true or false. Because they are not involved. I’m involved. I’ve been involved with the stuff all my life. But I’m involved. I know when you are telling the truth or when you are not.”

This appears to a pattern for the president. Take some action — fire a guy; hold a news conference; sign an executive order — then watch the coverage on television, then commentate on that coverage. Or better yet, predict the coverage: “Tomorrow, they will say, Donald Trump rants and raves at the press,” said the president at yesterday’s event. “I’m not ranting and raving. I’m telling you you’re dishonest people, but I’m not ranting and raving. I love this. I’m having a good time doing it, but tomorrow’s headlines are going to be Donald Trump, rants and rants. I’m not ranting.”

It’s the narcissist’s approach to media consumption.

3) Cable news is fleeting. “Memory for televised news tends to be poor,” notes Barrie Gunter, a professor of mass communications at the University of Leicester. “Most stories are forgotten within half an hour of a broadcast unless the viewer is paying close attention to it and is expecting to be tested afterwards. Stories at the beginning and end of the bulletin have an advantage and are remembered best. But interference from images that contain little support information for the text can render a TV news item almost useless at getting across anything other than main headlines. People don’t retain the lessons from television newscasts.”

On the one hand: Trump may be spending hours learning nothing at all. On the other hand: Instant amnesia may be the only counterweight to the programming on “Fox & Friends.”

Beyond news consumption, there’s the matter of briefing books. Obama famously spent long nights in the residence — generally the Treaty Room — reading through materials prepared for him by the White House staff secretary. “I do remember going over there and he had a basketball game with sound off in the background,” recalls Lisa Brown, who served as staff secretary for the first two years of the Obama White House. No matter how thick the briefing materials, says Brown, they’d come back “with underlines, with notes, with questions for people.”

As for Trump, he does take briefing materials into the residence at night, according to Shah. Perhaps those get just as much scrutiny as Don Lemon, though the New York Times offers this portrayal: “When Mr. Trump is not watching television in his bathrobe or on his phone reaching out to old campaign hands and advisers, he will sometimes set off to explore the unfamiliar surroundings of his new home.”

Mika Brzezinski and Joe Scarborough, hosts of MSNBC's "Morning Joe," say they won't invite White House counselor Kellyanne Conway on their show because she doesn't provide reliable information. (Peter Stevenson/The Washington Post)