Editor’s Note: Elliot Williams (@elliotcwilliams) is a CNN legal analyst. A principal at The Raben Group, a national public affairs and strategic communications firm, he was formerly a deputy assistant attorney general at the Justice Department and an assistant director at US Immigration and Customs Enforcement for the Obama administration. The views expressed here are the author’s. View more opinion on CNN.

CNN  — 

Nobody knows how much damage coronavirus will cause. But one thing is clear: the crisis has tested President Donald Trump – and he has proven to be an astonishing success in a way no president ever has before.

But let’s be clear: his success isn’t at leading a desperate nation. Instead, coronavirus has exposed the real success of the President’s unyielding assault on the media during his time in office.

Elliot Williams

Many in the public don’t know whom to trust anymore and the President has played a big role in that. This is particularly tragic during a national crisis, when the nation needs to rely on a free press more than ever.

Even a polarizing president can unify the nation in a time of crisis. There may be differing views about Ronald Reagan, but no reasonable mind can deny the comfort he provided us after the Challenger explosion in 1986. Contrast that with Trump on Sunday, who during a formal coronavirus briefing, while surrounded by uniformed public health officers (not modeling responsible “social distancing” behavior, mind you) couldn’t resist whining about “fake news.” Trump was unhappy about the natural skepticism from reporters about a misleading (or at least confusing) claim regarding access to information about coronavirus testing.

Any goodwill the President might deserve for suddenly adopting a more reasonable tone at coronavirus press conferences is undercut by his Twitter demeanor, which remains as petty as ever.

Presidents often have tense relationships with the media; the Obama administration in which I served certainly had its own. But Trump’s relationship with the press is something unique. The President regularly bullies or attacks the credibility of anything or anyone that isn’t fully in lockstep with him: the intelligence community, federal prosecutors, career diplomats, the Federal Reserve Board, federal courts, the National Security Council, the Centers for Disease Control and Prevention and top military officials, to name a few.

And the media are no exception. These entities have something major in common: They all play a critical role in the health and security of the American public.

Which brings us back to the media’s role in a public health emergency. While according to Pew, most Americans receive some news from social media and online sources, the risk of actual “fake news” from such sources is real. Americans need to be able to trust the credible sources and authorities that provide them with safety information.

For instance, recently major steps were taken across the country to mitigate the spread of coronavirus. Over just two days, the White House recommended limitations on social gatherings of more than 10 people, Los Angeles took aggressive steps to limit public activity, and my home city of the District of Columbia prohibited dining at restaurants.

To work, each of these actions in major cities requires a robust local and national press – and public faith – to burn the message into people’s heads. Moreover, journalists should be entitled to a little space to keep up with developments of the rapidly changing situation without being accused of lying by the leader of the free world.

No matter how seriously the President appears to now take coronavirus, his years of bashing the media and tweeting statements like “The Fake News Media and their partner, the Democrat Party, is doing everything within its semi-considerable power (it used to be greater!) to inflame the coronavirus situation, far beyond what the facts would warrant” have already done their damage.

The President has not walked back or apologized for such tweets, even now adopting the disproven narrative that he always known that coronavirus would become a pandemic. Even assuming that he has now shifted his tone and approach for the better, how many people exposed themselves to coronavirus while believing the President that it was a hoax?

We will likely never know.

Sadly, polling data confirm the problem. According to a recent NBC News/Wall Street Journal poll, when asked whether they worry a family member will catch coronavirus, 68% of Democrats said yes, while 40% of Republicans said yes.

In any political climate, it’s one thing for polling to split over how a President is performing. It’s entirely another when there is a yawning partisan divide over basic matters of public health and safety. With the President constantly crowing about how the press lies to the public, he deserves a tremendous amount of the blame for the disconnect.

In establishing himself as an independent arbiter of truth, he has created space for the public to discredit facts and rely on his own statements. Unfortunately, these range from patently false or misleading remarks like “when you have 15 [coronavirus cases in the United States], and the 15 within a couple of days is going to be down to close to zero,” to utter nonsense like “[Coronavirus is] going to disappear. One day it’s like a miracle, it will disappear” — a statement that would be laughed at by a 9th grade biology student.

So, while the war on “fake news” might just look like the grumbling of a President who’s sore about the coverage he gets from what he thinks is a biased media, it’s far bigger than that. It’s a destructive, ongoing attack that could bring with it massive public health costs.

So, congratulations, Mr. President! In undermining the free press, you have succeeded at something that seems to have been critically important to you for years. Now good luck cleaning up the mess you’ve created.