‘Trump has got a real problem’: John Dean explains to CNN's Tapper why McGahn could take down the president

On Monday, the former Richard Nixon White House counsel John Dean told CNN’s Jake Tapper how Trump's White House counsel could take him down.

For the past nine months, Don McGahn has cooperated with special counsel Robert Mueller. President Trump lashed out on Twitter and called Dean a "rat" and said that McGahn was nothing like him.

"The failing @nytimes wrote a Fake piece today implying that because White House Councel Don McGahn was giving hours of testimony to the Special Councel, he must be a John Dean type 'RAT.' But I allowed him and all others to testify - I didn't have to," President Trump wrote on Twitter. [sic]

Dean told Tapper that President Trump's tweet only proved that he doesn't understand what is really going on.

"I'm not surprised. He thrives on insulting people. This is typical Trump. It's also evidence that he doesn't really understand what happened back then," Dean said.

He added, "This is an invaluable witness. He's a real-time witness. You can infer from that article that he might have been actually testifying very shortly after the events when they were fresh in his memory. He had knowledge of them."

"He had been asked to do things that were not proper. He knew why he was being asked. He resisted. He resisted. So, this is pretty important testimony, and it's taken Trump 48 hours almost to understand what's going on here."

According to reports, McGahn testified for more than 30 hours with Mueller’s team.

"I think that's a lot of testimony. That's a lot of visiting and that's just the bottom of what they know. It could well have appeared to have been ongoing. So, I think Trump has got a real problem here. And I'm not sure how he's going to handle it."

Watch the clip below via CNN.