Journalist Carl Bernstein hit back against insults lobbed by President Trump on Wednesday, saying he stands by his July report that then-candidate Trump had prior knowledge of the 2016 Trump Tower meeting, something which Michael Cohen, Trump's former attorney, was allegedly prepared to tell special counsel Robert Mueller.

"I have spent my life as a journalist bringing the truth to light, through administrations of both parties,” Bernstein tweeted at Trump. “No taunt will diminish my commitment to that mission, which is the essential role of a free press. @CNN stands by its story, and I stand by my reporting," tweeted Bernstein.

.@realdonaIdtrump- I have spent my life as a journalist bringing the truth to light, through administrations of both parties. No taunt will diminish my commitment to that mission, which is the essential role of a free press. @CNN stands by its story, and I stand by my reporting. — Carl Bernstein (@carlbernstein) August 30, 2018

Bernstein's tweet follows a similar defense from CNN, which reads "Make no mistake, Mr. President, CNN does not lie."

Make no mistake, Mr. President, CNN does not lie. We report the news. And we report when people in power tell lies. CNN stands by our reporting and our reporters. There may be many fools in this story but @carlbernstein is not one of them. — CNN Communications (@CNNPR) August 29, 2018

Except here's the lie:

Lanny Davis - Cohen's attorney and lifelong friend of the Clintons later admitted that he was the source for CNN's story amid massive backpedaling over the claim, yet CNN specifically notes in the article that Davis declined to comment:

Contacted by CNN, one of Cohen's attorneys, Lanny Davis, declined to comment.

So either Davis is lying or CNN is, and CNN hasn't refuted Davis's claim that he was a source. Instead, they doubled down and insisted he wasn't the only source.

C’mon, Carl. Your reporting says Lanny Davis declined to comment. Lanny Davis admits he was actually an anon. source for you & Obama staffer @JimSciutto. Without even getting into the bogus story itself, that fact alone proves you’re “standing by” lies. https://t.co/fyJK9VyG7c — Donald Trump Jr. (@DonaldJTrumpJr) August 30, 2018

In a Wednesday night tweet, President Trump wrote "CNN is being torn apart from within based on their being caught in a major lie and refusing to admit the mistake," Trump tweeted Wednesday evening. "Sloppy @carlbernstein, a man who lives in the past and thinks like a degenerate fool, making up story after story, is being laughed at all over the country! Fake News"

CNN is being torn apart from within based on their being caught in a major lie and refusing to admit the mistake. Sloppy @carlbernstein, a man who lives in the past and thinks like a degenerate fool, making up story after story, is being laughed at all over the country! Fake News — Donald J. Trump (@realDonaldTrump) August 29, 2018

Degenerate fool?

Does Trump know something we don't? A 1989 Wahington Post exposé on Bernstein offers some clues - revealing that his angry, cheated-on ex-wife published a novel which "portrays a Bernstein-like character as an emotionally empty, self-absorbed, narcissistic man capable of having sex with venetian blinds."

When ABC Washington offered Bernstein a job as the Washington bureau chief in the 80s, the "power seemed to go to his head," reported the Post. (h/t Josh Caplan)

"I gotta tell you, at ABC, he was just a terrible screw-up. It's awful to say it. It was awful to watch it." About this time, people noticed that Bernstein was drinking more heavily. His life had gone beyond chaotic. While Nora was pregnant with their second child, Bernstein had his now-notorious affair with Margaret Jay, wife of the British ambassador. -Wahington Post

Perhaps this is what the President was referring to?

Later Wednesday evening, a feisty President Trump tweeted: “Lanny Davis admits being anonymous source in CNN Report.” @BretBaier Oh well, so much for CNN saying it wasn’t Lanny. No wonder their ratings are so low, it’s FAKE NEWS!"

“Lanny Davis admits being anonymous source in CNN Report.” @BretBaier Oh well, so much for CNN saying it wasn’t Lanny. No wonder their ratings are so low, it’s FAKE NEWS! — Donald J. Trump (@realDonaldTrump) August 30, 2018

Nearly two hours after Trump's first tweet, Don Jr. chimed in, calling Bernstein a "leftist hack" peddling "literal fake news."