Judge Andrew Napolitano said that former National Security Adviser Michael Flynn pleading guilty to making false statements to the FBI could lead to a "constitutional crisis."
As part of the plea deal, Flynn agreed to cooperate with Special Counsel Robert Mueller's investigation, which is looking into alleged Russian interference in the 2016 U.S. presidential election.
Court documents show Flynn acknowledged to investigators that at least two Trump transition members were involved in his outreach to Russian officials.
On "Shepard Smith Reporting," Napolitano explained that investigators will use Flynn to get information and possibly bring indictments against other Trump officials, including the president himself.
"If Robert Mueller has enough evidence - credible evidence - with which to charge the president of the United States with a crime, the constitutional crisis will come as he decides what to do," Napolitano said.
He explained that if Mueller has sufficient evidence, he will have to decide if he will indict the president or turn the evidence over to the House of Representatives.
"This has not happened and we don't know where it would go, if a sitting president is indicted," Napolitano said.
Napolitano noted that if Trump himself directed Flynn to make contact with Russians, a significant factor would be when it happened.
"If this occurred while Donald Trump was a candidate and the purpose of communicating with the Russians was to facilitate, encourage or justify their interference with the American political process, then you have a very serious criminal offense, which would probably constitute an impeachable offense," Napolitano said.
He added that if it occurred after Trump won the election, then it would still be an offense, although possibly not an impeachable one.
"Beyond this, the president of the United States has steadfastly, repeatedly and consistently denied that he had any knowledge of any involvement with the Russians. If Gen. Flynn contradicts that in a credible way under oath, we have a very serious problem on our hands," Napolitano said.
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