CNN host Don Lemon said President Donald Trump is "clearly trying to ignite a civil war in this country" after his speech to supporters in Phoenix, Ariz., on Tuesday night, and pondered whether the president has dementia.

"He has given oxygen to racists," Lemon said. "He hasn't really said anything [to] denounce the alt-right … He is clearly trying to ignite a civil war in this country. He has not tamped down race."

In what CNN described in its chyron as an "angry, divisive speech," Trump lit into the media and also defended his criticized response to the white supremacist violence in Charlottesville, Va., omitting in his remarks to the crowd that he once said "both sides" carried blame for violence there.

Lemon said if Trump worked in his newsroom and said those things, he would be fired. Lemon then read out a tweet by CNN commentator Ana Navarro that the only "defensible explanation" for Trump's behavior would be early-onset dementia.

Only possible defensible explanation for Trump's disgusting, unpresidential, narcissistic behavior, would be early-on-set dementia. Maybe. — Ana Navarro (@ananavarro) August 23, 2017

"Some people have been saying that for months, but listen—we don't know if that—he has—has he showed that he's fit for office?" Lemon asked, to which guest Maria Cardona emphatically said, "No."

Lemon also unloaded on Trump after his speech ended, calling it "unhinged" and "embarrassing" in an extended monologue.