A journalist who has covered some of the biggest moments in recent American history says Donald Trump's administration is now in "freefall".
Dan Rather, who was the anchorman for CBS Evening News for 24 years, says "[a] 'presidential' Trump is a punchline to a joke no one wants to have told."
In a lengthy Facebook post, Mr Rather accused Mr Trump of allowing conspiracy theories to dictate national policy.
"Conspiracy theories are corrosive in society at large. When they dictate national policy, they can be lethal," he wrote.
Pointing to Mr Trump's failure to back up claims that Barack Obama's administration wiretapped Trump Towers prior to the election, Mr Rather said anyone who "normalizes [President Donald] Trump ... will have to answer the future generations for their acquiescence, silence or sophistry - if, indeed, not outright cowardice."
Mr Rather then went on to accuse Mr Trump of "lies, innuendo and no evidence" regarding claims Mr Obama was not born in the United States and regarding claims of widespread voter fraud.
"The man who sends out a twitter tirade accusing a former President of crimes for which he provides no evidence, the man who doubles down when everyone with any sense pushes back, that man is our Commander in Chief."
Mr Rather said the Oval Office could be a bubble and that "power attracts sycophants and cynics".
"But I have never seen anything like this. The sheer level of paranoia that is radiating out of the White House is untenable to the workings of a republic.
"I have a real question if President Trump actually believes what he is saying. Even Richard Nixon, the most paranoid president to date, ruled for years with a relatively calm hand."
Mr Rather signed off with a call to action: "We have woken. We are paying attention. And we love our country too much to let it falter without a fight."