John Dean, who served as Richard Nixon's White House counsel and went to prison for his role in the Watergate break-in and cover-up, says Donald Trump's attempts to obstruct justice are even worse than Nixon's.

John Dean, who was central to the Watergate scandal that took down former President Richard Nixon, has described Donald Trump’s behavior as surpassing Nixon’s “for direct and personal involvement in the early White House cover-up.”

In other words, only four months into his presidency, Trump is worse than Nixon, according to someone who would certainly know.

In response to a Washington Post report exposing more of Trump’s actions in the unfolding Russian election investigation, Dean tweeted:

The Post reported that Trump asked Daniel Coats, the director of national intelligence, and Michael Rogers, the director of the National Security Agency, to publicly deny that there was evidence Trump colluded with Russia during the 2016 election.

Both men refused to comply with Trump’s unethical request.

“Senior intelligence officials also saw the March requests as a threat to the independence of U.S. spy agencies,” the Post explained, “which are supposed to remain insulated from partisan issues.”

The exchanges are yet more evidence of a plot by Trump to obstruct the investigation using the power of the presidency. He also allegedly pushed then-FBI Director James Comey to publicly clear him, which Comey refused to do. That refusal led to Trump firing Comey.

Dean was a first-person witness to Nixon’s criminal behavior and eventual downfall. He served as White House Counsel between 1970 and 1973. On Nixon’s behalf, he coordinated elements of the Watergate break-in, including transferring funds to the burglars and the subsequent cover-up. He ultimately went to prison on a reduced felony charge in exchange for his testimony.

Nixon’s cover-up caused him more trouble than the underlying crime, including his decision to order multiple law enforcement officials to assist him. Nixon fired the attorney general and special prosecutor investigating him, actions that were echoed by Trump when he fired acting Attorney General Sally Yates and Comey.

Dean later testified to the Senate Watergate Committee, publicly exposing the criminal behavior of Nixon and key figures in his administration. To avoid certain impeachment and removal from office, Nixon resigned in shame.

That Dean sees Trump’s behavior not only in the realm of Nixon, but surpassing his criminal behavior, is a testament to how far gone Trump’s presidency is in a very short period of time.