Peter Fonda was sounding absolutely unhinged.

He went on a profane tweetstorm against the president's policy on separating families that actually prompted the first lady to contact the Secret Service:

"We should rip Barron Trump from his mother's arms and put him in a cage with pedophiles and see if mother will stand up against the giant a**hole she is married to."

That sort of ugliness was just the beginning. In since-deleted tweets, Fonda said maybe "lying gash" Sarah Sanders should have her children taken away and be deported to Arkansas. And he called Kristjen Nielsen "a lying gash that should be put in a cage and poked at by passerby. The gash should be pilloried in Lafayette Square naked and whipped by passerby while being filmed for posterity."

I mean, these violent fantasies are pure sickness. Only later did Fonda come to his senses and apologize for the "highly inappropriate and vulgar" comments. Sony Pictures called his remarks "abhorrent, reckless and dangerous"—but isn't pulling his new film.

That helped unleash a new round in the long-running debate over the vitriolic tone that President Trump and his critics often take in this hyperpartisan atmosphere.

What I'm seeing is that the right frequently pounces on Trump's detractors and the left constantly savages Trump himself. It becomes a game of whataboutism where partisans justify the rough language on their side by pointing to some allegedly more nefarious language by those on the other side.

The president is a street fighter, no question about it. But I think too many of those who can't stand him, especially in the media, fall into the trap of using even worse language against him.

The result is a battle that increasingly takes place in the gutter. And it makes Trump haters look hypocritical when they use the very tactics for which they denounce him.

The New York Times calls this "the politics of rage":

"Mr. Trump's coarse discourse increasingly seems to inspire opponents to respond with vituperative words of their own. Whether it be Robert De Niro's four-letter condemnation at the Tony Awards or a congressional intern who shouted the same word at Mr. Trump when he visited the Capitol this week, the president has generated so much anger among his foes that some are crossing boundaries that he himself shattered long ago."

The paper reminds us that Trump has branded journalists, lawmakers and opponents "wacky," "crazy," "goofy," "mentally deranged," "psycho," "sleazy" and "corrupt." And there are many more, including that the media are the country’s “biggest enemy.”

But for all the emotional and heartfelt criticism of Trump's now-rescinded policy on family separation, those who throw around Nazi analogies or liken the detention facilities to concentration camps are going way too far.

I do think there's often a double standard in the way each side's excesses are covered. Every presidential insult and verbal punch draws heavy media attention and automatic criticism; fair enough.

But when DeNiro drops the F-bomb or Samantha Bee uses the C-word or Trump is called everything from a thug to mentally ill, the reaction is many quarters is hey, didja see what so-and-so said?And Hollywood liberals often applaud.

Both sides are too entrenched, and too invested in such attacks, to expect a return to civility. But the media have a special responsibility to hold everyone accountable for incendiary conduct.