"He's deteriorating in plain sight," one Republican strategist who is in frequent contact with the White House told Insider on Friday.
But one person who was close to Trump's legal team during the Russia investigation told Insider his public statements were "nothing compared to what he's like behind closed doors."
"He's like a bull seeing red," this person added. "There's just no getting through to him, and you can kiss your plans for the day goodbye because you're basically stuck looking after a 4-year-old now."