The most jarring development of a startling week in American politics was not the publication Friday of Michael Wolff’s tell-all book Fire and Fury: Inside the Trump White House, which ably confirms everything we knew, or should have known, about Donald Trump’s presidency.

The most jarring development was the authorization by the president of the United States of a move by his lawyers to block the publication of the book that details his dangerous duplicity and scorching incompetence. After an initial excerpt from the book was published, and additional excerpts began to circulate in Washington, Trump’s legal team moved on Thursday to block its publication.

“(He’s) helping me prove the point of the book,” Wolff said of the president’s legal threat. “This is extraordinary that a President of the United States would try to stop the publication of a book. This doesn’t happen—has not happened from other presidents, would not even happen from a CEO of a mid-size company.”

Wolff is right. This is not what presidents do. But this is what Trump did.

In an 11-page letter to Wolff and the president of publisher Henry Holt & Co.—and cc’d to the president—a lawyer with the firm that serves as litigation counsel for Trump wrote: “Mr. Trump hereby demands that you immediately cease and desist from any further publication, release or dissemination of the book, the article, or any excerpts or summaries of either of them, to any person or entity, and that you issue a full and complete retraction and apology to my client as to all statements made about him in the book and article that lack competent evidentiary support.”

Wolff stands by his book, telling NBC, “My credibility is being questioned by a man who has less credibility than perhaps anyone who has ever walked on earth at this point.”

The response from Holt & Co. was to move up the publication date for a book that is already topping best-seller lists.

The failure of the attempt by the president and his lawyers to censor this particular book will, in the eyes of some, make the “cease and desist” demand a footnote to the story of the worst week—so far—of Donald Trump’s presidency. But the book-banning demand is a serious matter.

The Authors Guild immediately recognized what was—and is—at stake. In a statement issued Thursday, the Guild decried “the unprecedented attempt by President Trump to block publication of a book” and declared, “We believe that the attempt to quash a book before publication is flagrantly unconstitutional.”

Noting that the letter from Trump’s law firm “fails to name a single instance of any specific statement in the book that is false and would rise to libel or invasion of privacy,” the Guild cut through the legal legerdemain and explained, “It is one thing for a private citizen to use libel laws to quash speech. It is unheard of for a sitting President to do so.”

The Guild’s president, James Gleick, argued Thursday that “This isn’t a country where we quash books that the leader finds unpleasant. That’s what tyrants do, not American presidents.”

The founders of the American experiment, fresh from fighting a revolutionary war against colonial oppression and the abuses that extend from “the divine right of kings,” wrote a constitution to guard against tyranny. The primary tool for preventing presidential tyranny—the instinct of the executive to imagine himself as “a king for four years”—was the power of impeachment. Arguing that “no point is of more importance than that the right of impeachment should be continued,” George Mason asked the Constitutional Convention in 1787: “Shall any man be above justice?”

The answer established by the framers of the US Constitution was Article II, section 4, of that document, which authorizes the House of Representatives to impeach and the Senate to try and remove a president who commits what were broadly defined as “high crimes and misdemeanors.” There is no high crime, no misdemeanor, more worthy of impeachment than the abandonment of the most basic premises of the Constitution by a president who has sworn an oath to defend it.

The House Judiciary Committee that in 1974 wrote articles of impeachment holding Richard Nixon to account gave its strongest support to the article that began: “Using the powers of the office of President of the United States, Richard M. Nixon, in violation of his constitutional oath faithfully to execute the office of President of the United States and, to the best of his ability, preserve, protect, and defend the Constitution of the United States, and in disregard of his constitutional duty to take care that the laws be faithfully executed, has repeatedly engaged in conduct violating the constitutional rights of citizens…”

The parallels between the Nixon impeachment and a potential Trump impeachment are many—especially when it comes to concerns about what the Watergate-era Judiciary Committee identified as “impairing the due and proper administration of justice and the conduct of lawful inquiries, or contravening the laws governing agencies of the executive branch and the purposed of these agencies.”

But Trump’s attempt to ban the publication of a book that reveals just how unfit he is to occupy the Oval Office appears to be unprecedented. “To the Guild’s knowledge, no prior President has sued a writer for libel, and for good reason,” explains the nation’s oldest and largest professional organization for writers. “The ability to criticize the government and its leaders lies at the essence of the First Amendment’s protection of free speech; and threats of libel lawsuits are one of the de facto primary means of curtailing free speech in this country today.”

With his attempt to cause an author and a publisher to “immediately cease and desist from any further publication, release or dissemination” of a book that does not meet with his approval, Donald Trump has shown a callous disregard for the First Amendment to the Constitution. The Authors Guild is right: This is what tyrants do, not American presidents. And the proper response to American tyranny is the prompt application of the power of impeachment to a president who has abandoned the duty that extends from his oath of office.