Appearing on a panel after Trump's post-acquittal speech wrapped up, Harwood called the event a "disturbing tableau for the country."
"It was dark because he's made clear that his mind is dark. This is somebody in deep psychological distress right now. Self-pitying, insecure, angry," Harwood told the panel. "He doesn't accept abstract concepts like right or wrong, like morality or immorality, like true or false. He recognizes what is good for him in the moment."
Harwood also ripped the Republican Party for being "reduced to sitting there applauding this rambling, disordered set of remarks."
Reporting from outside the White House later that evening, Harwood knocked what he described as Trump's "rambling soliloquy."
"The president's mood is distressed, he's wounded, he's angry and he's lashing out," Harwood told CNN anchor Erin Burnett. "President Trump thinks he himself is the victim here, and so he's lashing out."
He also went after the president for mocking the faith of Sen. Mitt Romney, R-Utah.
"By all signs, Donald Trump doesn't understand faith, he does not seem to be a person of faith," Harwood said. "He does not recognize the values that faith teaches us, distinctions between right and wrong. And so for him, this is a primal reaction to people who have hurt him and he wants to hurt them. He made that clear."
He added: "What is alarming about it... Republicans in his audience today were laughing and cheering along with him." He later slammed the GOP for not "restraining" the president.
CNN raised eyebrows last month when the network announced it had hired Harwood to be its White House correspondent. Harwood, who previously exited CNBC, was widely known for his overly-hostile moderating during a GOP primary debate in 2015.
Earlier this week, Hardwood faced backlash for claiming 25 senators who voted against hearing witnesses during Trump's impeachment trial represent "states of the Confederacy during the Civil War."
Fox News' Brian Flood contributed to this report.