(Thomas Johnson/The Washington Post)

The presidency is not a reality show, but President Trump on his first full day in office made clear that he’s still obsessed with being what he once proudly called “a ratings machine.”

He cares enough about it to send his press secretary, Sean Spicer, out to brazenly lie to the media in his first official briefing.

“This was the largest audience to ever witness an inauguration — period — both in person and around the globe,” Spicer said. And he added a scolding about widespread reports that differ from his evidence-free assessment: “These attempts to lessen the enthusiasm of the inauguration are shameful and wrong.”

Crowd size experts estimate Trump’s audience at far fewer than the million or more that Trump is claiming, and at far less than the size of the following day’s women’s march, which the new president has said little about. And side-by-side photographs showed the contrast between the comparatively thin gathering for Trump’s inauguration and the record-setting one in 2009 for former president Barack Obama’s first.

Ari Fleischer, a former George W. Bush press secretary, saw Saturday’s bizarre session for what it was.

(Monica Akhtar/The Washington Post)

“This is called a statement you’re told to make by the President. And you know the President is watching,” Fleischer wrote. (MSNBC’s Mika Brzezinski pegged it as “Sean Spicer’s first hostage video.”)

The mainstream media, including The Washington Post, appropriately made clear note of the falsehoods about crowd size. The New York Times called out “false claims” in a prominent headline, and many broadcast journalists challenged Spicer immediately — although they didn’t get a chance to do so to his face, since he took no questions.

CNN wisely chose not to air the briefing in full, but to report on it and to show parts, providing context. Fox News showed it in its full glory, infomercial style.

Some journalists, afterward, sounded stunned at what had transpired.

“Astonishing,” said Jim Acosta of CNN. “Jaw meet floor” was the reaction of Glenn Thrush of the New York Times.

The reaction is understandable. Some semblance of truth from the White House ought to be reasonable enough, especially on Day Two.

But nothing about this should shock.

Anyone — citizen or journalist — who is surprised by false claims from the new inhabitant of the Oval Office hasn’t been paying attention. That was reinforced when Trump adviser Kellyanne Conway told “Meet the Press” Sunday that Spicer had been providing “alternative facts” to what the media had reported, making it clear we’ve gone full Orwell.

Official words do matter, but they shouldn’t be what news organizations pay most attention to, as they try to present the truth about a new administration.

White House press briefings are “access journalism,” in which official statements — achieved by closeness to the source — are taken at face value and breathlessly reported as news. And that is over. Dead.

Spicer’s statement should be seen for what it is: Remarks made over the casket at the funeral of access journalism.

As Jessica Huseman of ProPublica put it: “Journalists aren’t going to get answers from Spicer. We are going to get answers by digging. By getting our hands dirty. So let’s all do that.”

She’s right. So was Tim O’Brien, executive editor of Bloomberg View and a Trump biographer, who urged journalists to remember that the White House briefing room is “spoon-feeding and Trump is a habitual fabulist.”

There’s a deeper story here, beyond a single briefing, no matter how memorable. Saturday made clearer than ever that President Trump intends to make the American media his foremost enemy.

During his first official visit to the CIA, Trump once again attacked the media, as he did throughout the campaign as he blacklisted news organizations and called reporters “scum.”

Journalists shouldn’t rise to the bait and decide to treat Trump as an enemy. Recalling at all times that their mission is truth-telling and holding public officials accountable, they should dig in, paying far more attention to actions than to sensational tweets or briefing-room lies — while still being willing to call out falsehoods clearly when they happen.

They also should quickly acknowledge and correct their own inevitable errors, as Time’s Zeke Miller did — multiple times and with an apology — after erroneously reporting that a bust of Martin Luther King Jr. had been removed from the Oval Office.

That didn’t keep the president from making Miller’s reporting error a major issue as he raged during his CIA visit: “This is how dishonest the media is.”

Trump wants a flat-out war with the nation’s media for one well-calculated reason: Because he believes it will continue to serve his political purposes, as it has for months.

Journalists should respond by doing their jobs responsibly, fairly and fearlessly, in service of the public good.

Somebody has to be the grown-up in the room. We’ve just been reminded of who it won’t be.

For more by Margaret Sullivan visit wapo.st/sullivan.