Dean made the remarks on CNN's "Tonight" with Don Lemon on Tuesday.
"So if the president did ask Matthew Whitaker if he could put a Trump supporter in charge of the SDNY investigation, is that an impeachable offense?" Lemon wondered. "President Richard Nixon faced obstructing and impeding the Watergate investigation and break in, but he resigned before there was a trial."
"Do you see Nixon/Watergate comparisons in what the president was reportedly trying to do here?" he asked.
"Every day I see comparisons," Dean replied.
Dean said both Nixon and Trump "have no real hesitation...of abusing their powers and using their powers in an abusive way."
"The difference is Nixon understood how the machinery of government works, he understood the presidency. Donald Trump really doesn't," Dean explained. "He's sort of learning as he goes along -- and I just think he's going to get more dangerous as he proceeds."
"So you have [Mike] Flynn, the Russia investigation, and now seemingly trying to influence the SDNY's Michael Cohen probe. Are we beyond Watergate territory right now?" Lemon asked.
"We are beyond Watergate, because of what's at stake here," Dean replied.
"Richard Nixon was never suspected as someone who might be an agent of the Russians or the Chinese or anybody else," Dean argued. "So his problem wasn't that he was in anyway suspected of being an a Manchurian candidate, he was anything but that, while this president certainly is suspected of that."
Lemon asked about Trump's pattern of asking his appointees to "un-recuse" themselves to oversee investigations involving the commander-in-chief.
"Don, that's not going to work, because the rank-and-file people in the Department of Justice, in the U.S. Attorneys offices they're going to balk if they see a corruption investigation being stamped down from the top," he replied.
"You know, they'll only take so much and if they see misconduct, they're going to speak out," Dean predicted. "There are going to be a lot of whistleblowers if this stuff starts happening."
Watch:
