When he was running for the presidency, Mr Trump would often or call in to the show Mr Scarborough co-presented with Mika Brzezinski, his wife. Mr Scarborough, 57, a former Republican member of Congress, would brag about calling Mr Trump to offer him advice, and such was their perceived friendship, officials at liberal-leaning MSNBC reportedly became concerned.
That is now ancient history. At some point along the road, Mr Trump fell out with Mr Scarborough and Ms Brzezinski, or at least their coverage of him.
The president launched a notoriously vicious Twitter attack on Ms Brzezinski, 53, in the summer of 2017, claiming he had turned the couple away from a New Year’s Eve party as she was “bleeding badly from a face-lift”.
In the latest assault on Mr Scarborough, launched over the Memorial Day holiday and as the number of US coronavirus deaths neared 100,000, Mr Trump accused the presenter of being involved in a murder.
Despite there being no evidence Mr Scarborough had any part in the 2001 death of his congressional aide Lori Klausutis, Mr Trump tweeted over the weekend to to his 80 million followers: “A blow to her head? Body found under his desk? Left Congress suddenly? Big topic of discussion in Florida...and, he’s a Nut Job (with bad ratings). Keep digging, use forensic geniuses!”
On Sunday morning, the president picked up the theme again. “A lot of interest in this story about Psycho Joe Scarborough. So a young marathon runner just happened to faint in his office, hit her head on his desk, & die?.”
The Daily Mail said it was the fourth time this month Mr Trump had accused Mr Scarborough of killing the young woman. It said she died in 2001 at the office after falling and hitting her head and that doctors ruled her death an accident as a result of an undiagnosed heart arrhythmia.
Mr Trump’s comments sparked immediate dismay and anger. The Washington Post’s top “fact-checker”, Glenn Kessler, who has a forthcoming book about the president’s dishonesty, wrote: “Re Trump’s crazed tweets suggesting @JoeNBC is complicit in murder, our book ‘Donald Trump and His Assault on Truth’ has an entire chapter devoted to his false attacks on perceived enemies. Coming June 2.”
Mr Scarborough and Ms Brzezinski did not respond to Mr Trump’s latest tweet. Last week, Ms Brzezinski appealed to Twitter founder Jack Dorsey to ban the president from the site.
On Sunday, she posted an image of the front page of the New York Times showing the names of 1,000 of the approximately 100,000 Americans to have died.
“#Trump100K This human catastrophe did not have to be so bad,” she wrote. “History will not look kindly at the botched response to repeated warnings over the course of months that this pandemic was coming.”