'They are deeply frightened': MSNBC panel shreds Trump and Rudy's frantic attempts to discredit Michael Cohen

A "Morning Joe" panel on Friday tore apart the effort by President Donald Trump and attorney Rudy Giuliani to attack the credibility of former Trump "fixer" Michael Cohen, who reportedly is prepared to tell special counsel Robert Mueller that the president was fully aware that his son planned to meet with Russian agents who promised dirt on then-rival Hillary Clinton.

MSNBC's Lawrence O'Donnell pointed out how ridiculous it was for Giuliani to attack Cohen's credibility as a witness given that he himself used several disreputable people as witnesses back when he prosecuted mobsters.

"He used mafia murderers as his witness to testify against other mafia murderers!" O'Donnell said. "And the jury sat there and decided which mafia murderer do they want to believe -- and they believed Rudy's."

Attorney Joyce Vance said that the purpose of the attacks on Cohen is to try to dissuade special counsel Robert Mueller from using him as a witness against the president.

"I think what we're really seeing here from Giuliani is he's trying to talk to an audience of one, but it's not the president," she said. "It's Bob Mueller. He's trying to give Mueller a reason to not pick up Cohen as a cooperator. 'Cohen is not credible, he's a liar, no jury will ever believe him.' And that tells me that Giuliani and the president are deeply frightened of what Michael Cohen might have to offer prosecutors."

Watch the video below.