Whenever I mention that the news media leans ridiculously far to the left, that it has lost half the country with its attitude and that the tone of the coverage of President Donald Trump is over-the-top hostile, I get the same darn reaction.

The eye roll.

That big Anderson Cooper CNN eye roll, often accompanied by a few theatrical sighs.

And when I leave the newsroom, it gets even worse on social media.

But now Harvard University's Shorenstein Center on Media, Politics and Public Policy has come out with a study of media coverage of the Trump White House in its first 100 days.

It is astonishing because it comes from Harvard, not exactly the bedrock of American conservatism.

The study found that in Trump's first 100 days in office, the tone of the news coverage of the president has been a whopping 80 percent negative to 20 percent positive.

CNN and NBC struck a 93 percent negative tone on their Trump stories, with only 7 percent positive. CBS was third in the anti-Trump race, with a 91 to 9 ratio. And the pro-Trump Fox News? That network was 52 percent negative to 48 percent positive.

So what does fair and balanced really mean, anyway?

"It confirms what most people understand," said Tom Bevan, publisher and co-founder of RealClearPolitics, one of the go-to websites for media and political junkies.

Bevan spoke as a guest on "The Chicago Way" podcast that I co-host with WGN-AM radio producer Jeff Carlin.

"The response will be that Trump is deserving of this kind of coverage because he's conducted himself inappropriately, and these are self-inflicted wounds, and the press is doing nothing but covering him and his actions. But that's a little bit disingenuous," Bevan said.

"I think Trump has been treated unfairly by the press in his first 100 days. Everything he does is seen as a five-alarm fire."

Trump bears some of the blame for this. He mocked the media, called journalists "the enemy of the people," and went to Washington with much vulgar bragging, essentially promising he'd kick the political establishment right in the private parts. And telling the Russians that former FBI director James Comey is a "nut job" doesn't help.

And now the establishment kicks back.

Many Beltway journalists are essentially establishment creatures, gatekeepers for the political ruling class, members of that class and fierce guardians of their place in the empire. The political class sees Trump and the 62 million Americans who voted for him as the stuff they scrape off their shoes.

While Trump's 80-20 negative coverage ratio is amazing, Presidents Bill Clinton and George W. Bush also received much negative coverage in their first 100 days, at about 60-40 ratios.

So how was President Obama covered in his first 100 days? With a 60-40 positive to negative ratio, according to the Harvard study.

"That's a significant shift, a significant difference," Bevan says. "I think this is reflective of the fact that the media does root from the press box, and they do cheer for certain personalities, and they do cheer against others."

I have my own memory of the media's tone after Obama took office. It wasn't merely positive, it was adoring, gushy, in the way a small child looks up to a beloved parent, or a dog to the master who gives it biscuits.

It was as if the media were hugging a magical unicorn. Obama wasn't only given the benefit of the doubt. He was handed the Nobel Peace Prize though he hadn't done anything to earn it. And critics were trashed as nothing but racists.

Obama controversies, from his administration's gun-running scandal in the "Fast and Furious" debacle to using the IRS as a weapon against conservative groups, were covered, somewhat. But generally, the tone was muted, respectful, nothing like it was for Trump or the Clintons.

Later, in Hillary Clinton's failed 2016 campaign, leaks of Democratic National Committee email — whether hacked by the Russians or not — demonstrated collusion between journalists and Democrats. But that cozy relationship has never properly been addressed, and that avoidance undermines the credibility of journalism as the media challenges Trump.

"Because of the way the press covered Obama, they lost so much credibility," Bevan said. "And because they did not take these things seriously, the IRS scandal, Fast and Furious, you could go down the list of where they turned the other cheek. … And now where they're giving Trump the third degree on everything, that makes the contrast all that much greater.

"So you have a certain segment of the public, the people who voted for Trump, who literally do not trust what the media says."

And the divide between rigidly defined political tribes, one courted by the media, the other dismissed by it, grows even wider.

"It's not good for journalism, and it's not good for the country," Bevan said.

Agreed. But I don't see it changing any time soon. Do you?

John Kass is a columnist for the Chicago Tribune. His Twitter handle is @john_kass.