Errol Louis is the host of "Inside City Hall," a nightly political show on NY1, a New York all-news channel. The opinions expressed in this commentary are solely those of the author.

(CNN) The shocking decision by press secretary Sean Spicer to bar CNN, The New York Times, Buzzfeed, Politico and the Los Angeles Times from a news briefing Friday signals that, for all its bluster and bravado, the Trump White House is an administration under siege.

In the face of the President's many public misstatements, obvious financial conflicts of interest and troubling ties to Russia, the White House has decided to launch an all-out attack on the news organizations that reliably report on the administration's fables and foibles.

Expect to see the media close ranks and fight for the public's right to observe and report on government without fear of official retaliation. To their credit, the Associated Press and Time walked out of Spicer's briefing when it became clear he was trying to punish selected news outlets.

It's reminiscent of a 2009 incident in which the Obama White House tried to exclude Fox News from interviewing a newly-appointed administration official, Kenneth Feinberg -- and got a brusque reply from the bureau chiefs of ABC, CBS, CNN and NBC that they would skip planned interviews with Feinberg unless Fox was included.

That professional solidarity will likely reassert itself. The White House Correspondents Association has already announced plans to respond to Friday's antics.

But don't expect Trump's unhinged attacks on media to end anytime soon. He gave a typical rant at the Conservative Political Action Conference on Friday.

"I want you all to know that we are fighting the fake news," he said . "It's fake, phony, fake. They have a professional obligation as members of the press to report honestly. But as you saw throughout the entire campaign, and even now, the fake news doesn't tell the truth."

That's a slightly cleaned-up version of Trump's practice of calling the media "scum" at his campaign rallies. It echoes the recent statement by Trump's top strategist, Steve Bannon, who told the Times , "The media should be embarrassed and humiliated and keep its mouth shut and just listen for awhile," and, "The media has zero integrity, zero intelligence, and no hard work."

As any seasoned reporter knows, that kind of squealing, with pointless insults, is the sound made by politicians when the truth makes them feel cornered and uncomfortable. Their bleating, in fact, signals that it's time to turn up the heat.

JUST WATCHED Spicer: We have a respect for the press Replay More Videos ... MUST WATCH Spicer: We have a respect for the press 00:45

And that is what will happen. In the Trump presidency, there are too many financial conflicts of interest to ignore, and White House efforts to spin or suppress coverage of Russian meddling in our elections is backfiring.

The Trump White House is a full-employment program for investigative reporters, and they are building an impressive, devastating body of work, thanks to a President who routinely invents facts and utters or tweets outright falsehoods almost daily. News outlets -- including CNN -- have a basic obligation to point out when Trump is telling lies, and that is where the conflict begins.

Journalists have reported that Trump spent years promoting the lie of "birtherism" to discredit former President Obama, which the new President has never apologized for.

When Trump claimed that he lost "hundreds" of friends on 9/11, columnist Mike Daly challenged him to name one -- just one -- and never got an answer. When he claimed to have seen "thousands" of Muslims celebrating on 9/11, that, too, turned out to be false.

For weeks, Trump and his aides have been claiming he enjoyed "one of the biggest Electoral College victories in history," which is close to the opposite of true. (He actually ranked 46th out of 58 elections).

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Trump falsely claimed that intelligence agencies had no idea who tampered with the November election, at a time when American intelligence already knew that Russia was the culprit.

The White House staff, too cowed to break their boss of the habit of making things up, is stuck cleaning up the President's misstatements, plugging leaks, and picking pointless, unwinnable fights with media organizations.

It's a thankless, hopeless job and will provide journalists -- and the late-night comedy writers, our wisecracking professional cousins -- with endless opportunities to tell a modern version of an ancient tale.

We're chronicling, once again, a strange story about the emperor's new clothes, and a royal court of flatterers too far gone to recognize that, sooner or later, people will see the truth.