"Nixon didn't have that kind of Department of Justice," John Dean said on Friday. "Nixon couldn't use the department as he wanted to."
John Dean served under Richard Nixon and helped cover up the Watergate scandal. Barr has issued a memo insisting he approve any investigation into a 2020 candidate.
John Dean, a member of former President Richard Nixon's White House Counsel said on Wednesday that President Donald Trump's lawyer Alan Dershowitz "unimpeached Richard Nixon" with his most recent arguments defending Trump.
John Dean on Sunday said that Senators won't buy Trump's legal defense brief because they're mostly lawyers and the document is "not legally sophisticated."
The White House counsel during the Watergate scandal, John Dean, made the claim after the first public hearings with two witnesses.
Deutsche Bank all but admitted that it holds President Donald Trump's tax returns in a federal appeals court filing.
Several members of President Donald Trump's staff came straight from stints on cable news.
"One of the post-Watergate norms was that attorney generals did not serve as the president's personal counsel," said John Dean, who served as White House counsel to President Richard Nixon.
"Trump's is making the long nightmare of Nixon's Watergate seem like a brief idyllic daydream," tweeted John Dean.
"I have nothing to hide and have demanded transparency so that this Rigged and Disgusting Witch Hunt can come to a close."
Will Don McGahn, the White House counsel, save Trump from the Russia probe? Or will he be forced to turn on his boss, as John Dean did to Nixon?