National security expert: 'Humiliated' Priebus and Spicer are big threats to Trump in Mueller probe

National security analyst Juliette Kayyem told CNN on Sunday that former White House Chief of Staff Reince Priebus is "neither a son nor a true believer" to the President Donald Trump and poses a significant threat to the administration if he or ousted Press Secretary Sean Spicer becomes a cooperating witness in the Mueller investigation.

There are likely two major points that the Mueller investigation is currently studying, Kayyem said, the firing of former FBI Director James Comey and the composition of Donald Trump, Jr.'s statement offering a false explanation for his meeting with a group of Russians and his father's campaign staff in June.

"We have to believe that Priebus was in the room" for the decisions leading up to these events, sh said. "People conversed via email and conversations where had."

Furthermore, she said, "what has to worry the White House right now" is that Priebus -- former director of the Republican National Committee -- is not a family relation to the president like Jared Kushner or Donald Trump, Jr nor is he a "true believer" like Steve Bannon.

"To me, he seems like a very weak link," Kayyem said, which is how conspiracy cases are constructed by prosecutors. They find the person in the crime most likely to turn on the other perpetrators and make them a cooperating witness.

Anchor Ana Cabrera pointed out that the Mueller probe would still like to speak to White House Special Counsel Don McGahn, Communications Director Hope Hicks and former Press Secretary Sean Spicer. Priebus and Spiecer, she noted, had "some pretty humiliating moments" working for Trump, raising the question of whether they will be loyal to the White House.

"If the White House can't answer that question affirmatively, they have to be nervous," Kayyem said.

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