Adam Schiff explains the creation of the wall between the presidency and the Justice Department:

In the run-up to the release of a deliberately misleading memo, some Republicans hyped the underlying scandal as “worse than Watergate.” When it was published, however, it delivered none of the salacious evidence of systemic abuse that it promised—only a cherry-picking of information from a single FISA court application. The memo’s release provided none of the vindication the President sought or would claim, but it was hugely consequential nonetheless, in how it undermined the system of checks and balances designed to insulate the FBI from White House meddling established in the wake of Watergate.

The years after the Watergate scandal saw multiple Congressional investigations into misuses of law enforcement and intelligence powers. Under the leadership of Director J. Edgar Hoover, who served in that role for nearly 40 years, the FBI targeted domestic political groups it deemed to be “subversive” for unconstitutional surveillance and covert actions. The targets of these actions included socialist groups, anti-war protesters, and civil rights groups and leaders, among them Martin Luther King, Jr.

Groups, in other words, that wanted reforms, which should not be seen and treated and spied on as “subversive.” Framing all dissent, or all dissent from the left, as “subversive” is a misuse of law enforcement and intelligence powers.

Jimmy Carter campaigned for President in 1976 promising a scandal-weary nation that he would wall off the Department of Justice and FBI from political influence and direction. As President, Carter did just that, for the first time putting in place formal rules to govern interactions between the Department of Justice and the White House. Perhaps more important, he established an expectation that the extraordinary powers of the Department of Justice and the FBI would not be wielded as a cudgel against the political opponents of the president.

New checks and balances, and oversight mechanisms, were added in all three branches of government. The Foreign Intelligence Surveillance Court is one.

What we have witnessed during the first year of the Trump Administration is a determined effort to demolish the separation between politics and the fair administration of justice—an attempt to turn the DOJ’s investigative powers into the personal political tool of the president.

The president in the person of Donald Trump, that is. He doesn’t give a rat’s ass about what happens in the future. For all we can tell he thinks he’ll never die and never be required to leave office.

[A] year later, it has become clear that the president views the idea that the DOJ should be anything other than an extension of his political operation as an unacceptable constraint on his authority. He told a reporter in December that he has “the absolute right” to do whatever he wants with “his” Department of Justice. The president has sought to put that statement into action from the very day he was inaugurated.

Remember that? I remember the horror and disgust when I watched him say that.

Both the president’s public statements and his private actions make it clear that he is seeking nothing less than to destroy the institutions and norms that shield the Department of Justice from his direction. This is all the more pernicious considering the fact that his own campaign is under investigation for possible collusion with the Russians in their interference in the presidential election. He would take the reins of the FBI to protect himself and to deploy their immense investigative powers against his political opponents at will.

During numerous oversight hearings over the years, I had many occasions to question former FBI Director Robert Mueller about the Bureau’s important work. Director Mueller frequently referenced in his testimony a little-known requirement for FBI trainees—each class of FBI agents would visit the Holocaust Museum to get a visceral look at what can result when law enforcement becomes a tool of repression, or worse.

As they launch their all-out assault on the pillars of the rule of law in this country, Republicans would do well to remember the abuses that prompted the creation of the wall between the DOJ and the White House, and the stakes if the FBI becomes simply another instrument of the President’s power.

Let’s hope they do remember. I feel as if we’re all on a tightrope.