Watergate veterans have seen this movie before about a president firing his attorney general to stop an investigation.

It didn’t work back then, and the consensus among three Watergate insiders interviewed by The Daily Beast is that it won’t work now. Just as the Saturday Night Massacre in October 1973 marked the beginning of the end for President Nixon, who resigned in August 1974, President Trump would grease the skids for himself if he tries to replace Attorney General Jeff Sessions with someone who would fire special counsel Robert Mueller.

“Mueller is the kind of guy who would say, ‘Fire me without cause, and I’m going to Court.’ And that could end up strengthening the Special Counsel,” says John Dean, Nixon’s White House counsel during much of Watergate.

“They can’t just cook up a PR campaign. It’s like the Muslim ban. You just can’t do it and pretend there’s cause. The courts could come in and play havoc with Trump. It’s amazing the institutions are working exactly the way they should. It’s a pleasant surprise.”

Conservative backing for the embattled Sessions appears to have scared Trump off Sessions, at least for now, as some Republicans are beginning to show some backbone. Senate Judiciary Chairman Chuck Grassley tweeted that there is no room on the committee’s schedule to confirm a new AG—and if Trump tried to slip one in while the Senate was in recess, it would almost certainly trigger a constitutional crisis.

Public outrage forced Nixon to name a second special prosecutor to replace the fired Archibald Cox. The White House thought Texas lawyer Leon Jaworski wouldn’t be overly aggressive. After he heard the tape of Dean telling Nixon there is a “cancer on the presidency,” Jaworski told Dean he knew the president was “guilty as sin.”

I asked Dean if he thought we could get that kind of clarity today. After all, as Trump likes to point out, the FBI has been investigating the Russia connection for a year, and no one has been charged with a crime. “We’re in a different technical era,” Dean replied. “Who knows what’s out there today. Who knows what the NSA is sitting on. None of us have seen this intelligence.”

As news has poured in over the less than 200 days that Trump has served as president, people have forgotten how “agonizingly slow Watergate was,” says Dean.

Nixon’s resignation on Aug. 8, 1974 came 782 days after the June 17, 1972, break-in. It was 920 days after the break-in that a jury found former Attorney General John Mitchell and aides H.R. Haldeman and John Ehrlichman guilty of conspiracy to obstruct justice.

Elizabeth Holtzman was a member then of the House Judiciary Committee, chaired by Democrat Peter Rodino in the Democratic controlled House, and in her telling, the Democrats took no action even as the taping system in the White House was disclosed, along with Dean’s “cancer on the presidency” and reports of the Watergate burglars being paid off with hush money (PDF). There were serious abuses of power, if not criminality by the president. In July of 1973, Father Drinan, a Democratic congressman from Massachusetts, filed an article of impeachment based on Nixon’s secret bombing of Cambodia.

“And nobody paid attention,” she says, even as Nixon was trying to dismantle a signature Great Society program, the Office of Economic Opportunity. “So you had the president thumbing his nose at limitations of power, but none of that moved anybody in the leadership of the House. Peter Rodino had no interest in impeachment. It was really forced by the American people.”

The trigger event was the Saturday Night Massacre. Members of the House were inundated with phone calls and telegrams. “The American people were outraged. It was an amazing shift in public opinion,” says Holtzman. “My office was flooded with messages. That’s what started the process [of impeachment]. It was not a partisan process.

“The lesson for Trump is if the American people realize that he’s threatening our democracy, and they don’t want to be a banana republic, the president can’t pick his prosecutor. They can force the Congress into action. Nixon had a huge landslide victory in 1972 and 11 months later, the Saturday Night Massacre was the beginning of the end. We expect our president to obey the law.”

When the Senate Judiciary Committee confirmed Elliot Richardson as Richard Kleindienst’s successor in May ’73, they made him name a special prosecutor to their liking, Archibald Cox, and pledge that he would not fire Cox except for “extraordinary improprieties,” a Justice Department regulation that Deputy Attorney General Rod Rosenstein has adopted in saying he would not fire special counsel Robert Mueller except for “cause.”

Richard Ben-Veniste was one of the lead Watergate prosecutors, “following money to find a motive,” he recalled to The Daily Beast, from the Committee to Re-elect the President (CREEP) and then ultimately the White House.

He explains that here, investigators are probing Trump’s financial dealings to determine whether they provide a motive for Trump asking Comey to go easy.

Ben-Veniste reminds those impatient with the pace of the Russia investigation that for a long period after the break-in, the White House was successful at deflecting investigative efforts to determine who sponsored it. Those efforts to deflect turned out to be obstruction of justice, so a separate crime was committed.

As today’s investigation unfolds, he cautions that “we are drifting into what may be uncharted waters if Trump makes good on his threat to fire Mueller. That would create a constitutional crisis.”

Asked how that might play out, he says it’s “unclear whether Trump would find anyone” to fire Mueller if Rosenstein refused. Asked how far down in the Justice Department Trump could go, Ben-Veniste said, “I don’t know if the elevator goes down that far.”

He concluded our conversation saying that if Trump does what everybody is advising him not to do, and one way or another, gets rid of Mueller, it will come down to “whether Republicans in Congress can put country above party. Our system will be severely tested, and we will find out whether we are a government of laws, where the rule of law is respected, or whether an outrage like firing a person lawfully appointed is acceptable to one political party.”

If Trump understood Watergate, he’d be having second thoughts about trying to push out Sessions, says Dean.

Unlike Sessions, who has significant support both in the Senate and in the conservative media, Kleindienst was easy to toss overboard. During marathon confirmation hearings over a record 22 days, he repeatedly perjured himself on his knowledge of an antitrust case that involved a $400,000 payoff to the 1972 Republican convention. The case had nothing to do with Watergate, but Kleindienst resigned under fire the same day (April 30, 1973) that Nixon announced the resignations of Haldeman and Ehrlichman, and fired Dean.

At least Nixon didn’t trash Kleindienst in public, I ventured in my conversation with Dean. “Nixon did that in private,” he said, before there was Twitter. “There’s no one who worked for Nixon he hadn’t trashed on the tapes.”

Dean calls the break-in of Daniel Ellsberg’s psychiatrist’s office in September of 1971 the reason the White House was so concerned about the Watergate break-in. Gordon Liddy, who headed the White House Plumbers unit (named for its initial mission of plugging leaks), had used two of the same guys, who were now in jail and could tie the break-ins to the White House. “Otherwise we would have cut the Re-Elect loose,” says Dean.

Liddy’s plan had gotten shot down twice before Mitchell signed off, saying, “give them $250,000 and see what they come up with.”

The casual straying from dirty tricks to criminal behavior is striking. “We wrote the book on what not to do, and Trump doesn’t seem to have any knowledge of what’s in that book,” says Dean.

“A lot of Watergate is just bungling—it’s pure bungling—stupid things, like not hiring a lawyer. I tried to get Ehrlichman to agree to a criminal lawyer on my staff after Liddy confessed to me the same people were used in the Ellsberg break-in—the first I heard of the Ellsberg break-in. Ehrlichman shot me down.”

After he left the White House, Dean learned of a handwritten memo signed by Ehrlichman authorizing the Ellsberg break-in “as long as it is not traceable to the White House.” It was an options memo on how to deal with Ellsberg, who had released the Pentagon Papers, and one of the options suggested by the Plumbers was to enter his psychiatrist’s office, take his files and use them to discredit him.

Nixon launched into the cover-up very early, not because anybody told him about the Ellsberg situation, but because he was concerned about Mitchell, says Dean. “But for John Mitchell, he never would have become president. Mitchell is to Nixon what Trump’s family is to him—you can’t get any closer.” When Nixon came to New York from California, Mitchell set him up as a partner in a prestigious law firm, put money in his pocket, and when Nixon decided to run again in 1968, Mitchell ran the campaign.

Mitchell didn’t want to be attorney general, according to Dean, but Nixon insisted, and the president was very worried on a personal level about Mitchell. “And that comes through on the tapes,” says Dean. “Four days after the arrest of the Watergate burglars, there’s a conversation where Nixon says, ‘Let’s just put all the facts out, put this thing behind us—but if that’s going to hurt Mitchell, we can’t do it.

“That was a bungle,” says Dean. At every point where they could have cut their losses, they dug in deeper, and the crimes piled up under the heading conspiracy to obstruct justice. There was also the cover-up Nixon got away with, says Dean, by intentionally disrupting President Johnson’s efforts to get peace in 1968.

Nixon biographer John Farrell found the evidence in Haldeman’s notes, “and if that isn’t treason it sure does look, feel and smell like it,” says Dean. “It was long suspected that Nixon wanted to break into the Brookings Institution when he heard they had ‘bombing halt’ papers. He might have been worried they had papers somehow showing what he had done with South Vietnam.”

The Republic survived Watergate and people thought the safeguards put in place afterward ensured that a scandal of that magnitude could never happen again. Forty government officials were indicted or went to jail. One Senate investigator who did not want to give his name told The Daily Beast, “In retrospect, everyone in the administration who got anywhere near Watergate, even tangentially, lied or sat still while other people lied. It was a lesson in an administration going absolutely wild. My whole generation of lawyers and politicians feel this is history repeating itself—the same personal characteristics, personal weaknesses, the same personal desire to acquire and embrace power.”

Some people saved their reputation then, notably Attorney General Richardson and his deputy, William Ruckelshaus, who defied Nixon’s order to fire the special prosecutor. We’re waiting for today’s profiles in courage. There should be ample opportunity.