Ex-Watergate prosecutor: We need to question legitimacy of Trump's presidency
President of the United States Donald Trump speaking at the 2018 Conservative Political Action Conference (CPAC) in National Harbor, Maryland. (Gage Skidmore/Flickr)

Former Watergate prosecutor Nick Ackerman explained to MSNBC's Ali Velshi on Wednesday how the guilty pleas by longtime Donald Trump attorney and fixer Michael Cohen has brought into question the legitimacy of the current president.

Loyola Law School professor Jessica Levinson pointed out that Cohen's guilty pleas beg the age-old question, "What did the president know and when did he know it?"

"Because Michael Cohen has said, 'No, I didn't do this on my own, this was not a rogue mission, this was President Trump telling me, yes, let's try and pay these people off to influence the election,' that's the moment where we have liability for the president," Levinson noted.

"That is the moment in which the legitimacy of this presidency comes into question," Velshi noted. "Some crime that may have resulted in the president gaining this presidency, that speaks to the legitimacy of this presidency, the legitimacy of this presidency came under great pressure last night."

"Of course," Ackerman replied. "This is what its all about."

"You've got him now involved as a co-conspirator with Michael Cohen, this is not some simple campaign violation," he concluded.