"Under the unitary executive theory, the president has the right to tell the FBI what to do," Dershowitz told CNN’s "New Day" anchor Chris Cuomo, invoking a theory that holds the president possesses the power to control the entire executive branch of the government.

"Thomas Jefferson managed the trial against Aaron Burr. President [Lyndon B.] Johnson interacted with the Justice Department and FBI."

However, he continued, the fact that Trump is president cuts both ways, Dershowitz continued.

"He has the power to tell them what to do," said Dershowitz, but since the president also was the only person who could have fired Comey, it’s not clear if he obstructed justice if he suggested to Comey to "go soft" on former National Security Agency Director Michael Flynn, as Comey has suggested and written in a memo.

"This is a complex and difficult issue, which we will never reach," said Dershowitz.