(CNN) President Donald Trump got some very bad news Friday, when his former campaign chairman Paul Manafort pleaded guilty to two counts, including one related to witness tampering.

The real danger for Trump lies in Manafort's decision to cooperate with the Justice Department. The revelation that Manafort has joined the growing list of " flippers " in special counsel Robert Mueller's investigation into Russia's 2016 election interference is a massive development, Chris Cillizza writes -- bringing investigators ever closer to the President and his inner circle.

The news must surely come as a blow to Trump, who only a month ago called Manafort a "brave man" who would not "make up stories in order to get a 'deal.' " The President watched coverage of Manafort's plea deal on television from the White House residence, CNN's Jeff Zeleny reported , per a person familiar, and was extraordinarily quiet on Twitter throughout the day. Asked about Trump's mood in the wake of this, an official who had spoken to him declined to say.

On the other side of the split screen, a week that started with the country on edge as Hurricane Florence approached the East Coast now ends with slow and steady devastation in the Carolinas . The storm's "violent grind" is set to continue through the weekend, depositing 40 inches of rain in some areas -- and dominating the airwaves and attention of the nation.