'This is going to be earth-shattering': Trump aide Michael Cohen to testify before Senate on Tuesday
President Donald Trump's longtime personal attorney Michael Cohen (Screen capture)

President Donald Trump's longtime personal attorney Michael Cohen is set to appear before the Senate Intelligence Committee on Tuesday, which an MSNBC panel agreed is "going to be earth-shattering."

"If you compare Donald Trump to a mafia don, this is his consigliere. This is the guy who knows all the secrets," said terrorism expert Malcolm Nance.

Cohen's name came up repeatedly in emails between the Trump campaign and Russian officials, including emails in which Cohen was feverishly trying to set up a Russian real estate deal that would entail a Trump Tower in Moscow.

The Senate may not be able to compel Cohen to reveal everything he knows, said Nance, but the investigation could learn a key question: "Was he acting independently or as an agent of the president?"

"This is going to be earth-shattering testimony if it comes out," he continued.

"We are looking at testimony that could be explosive," Roll Call's Jonathan Allen said, but hastened to add, "The real thing to keep an eye on is the Mueller investigation. The Senate Intelligence Committee has a role in all this, but it is a minor one compared to the Mueller probe."

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