On July 27, 1974, the House Judiciary Committee approved three articles of impeachment against Richard M. Nixon. The second article charged that President Nixon abused the powers of the presidency either by using or trying to use federal investigative agencies against his political enemies or by interfering or trying to interfere with lawful investigations by those agencies into his own wrongdoing or that of his subordinates. He tried to get dirt on his opponents through the IRS. He ordered the FBI to conduct investigations of actual or suspected enemies in and outside of the government. He sought to suppress investigations into the growing Watergate scandal. As the fifth specification in the articles of impeachment put it:

In disregard of the rule of law, he knowingly misused the executive power by interfering with agencies of the executive branch, including the Federal Bureau of Investigation, the Criminal Division, and the Office of Watergate Special Prosecution Force, of the Department of Justice, and the Central Intelligence Agency, in violation of his duty to take care that the laws be faithfully executed.

In short, the House Judiciary Committee voted to impeach Nixon because he sought to turn the immense power of the Justice Department and federal criminal investigative agencies against his political adversaries. Although these articles of impeachment were never approved by the full House of Representatives because Nixon resigned before a vote could be taken, it received more votes in committee than any other proposed article. No respectable scholar of the Constitution doubts that directing the criminal justice and intelligence systems of the United States against political opponents, for purposes unrelated to the impartial enforcement of the law or preservation of legitimate national security interests, is among the impeachable “high crimes and misdemeanors” of Article II, Section 4.

Friday morning, President Donald Trump sent out a series of tweets in which he explicitly urged the Justice Department and the FBI to investigate Hillary Clinton and the Democratic Party for a grab bag of supposed offenses—emails deleted from then–Secretary of State Clinton’s private server, the Russia-uranium kerfluffle, activities by Tony Podesta (lobbyist and brother of Secretary Clinton’s campaign manager), and the allegation that officials at the Democratic National Committee worked with Clinton’s campaign to give it a boost over Sen. Bernie Sanders’.

The Trump tweet-string included these gems:

Everybody is asking why the Justice Department (and FBI) isn't looking into all of the dishonesty going on with Crooked Hillary & the Dems.. — Donald J. Trump (@realDonaldTrump) November 3, 2017

....People are angry. At some point the Justice Department, and the FBI, must do what is right and proper. The American public deserves it! — Donald J. Trump (@realDonaldTrump) November 3, 2017

Trump followed up these tweets with statements to the press in which he said he is “disappointed” with the Justice Department and would not rule out firing Attorney General Jeff Sessions if Sessions won’t investigate Democrats. In my view, Trump’s tweets tiptoed right up to the line of an impeachable offense. His subsequent statements to the press stepped firmly over it.

Using the Nixon precedent as a template in order to show that Trump’s behavior is impeachable, several requirements must be met:

First, he must be seeking to employ the criminal investigative powers of the federal government against his political opponents. That is unquestionably the case.

Second, he must be acting, in the words of the Nixon impeachment article s , “for purposes unrelated to national security, the enforcement of laws, or any other lawful function of his office.” Although his most devoted adherents may claim otherwise, it is impossible to divine any legitimate nonpolitical purpose in his call for action by the Justice Department. His specific accusations don’t hold up to any kind of scrutiny:

Although it is doubtless a matter of intense interest for members of the Democratic Party, whether the DNC did or didn’t favor Clinton can by no stretch be translated into a violation of law, and still less a fit subject for a criminal investigation by a Justice Department controlled by the opposing party.

The Clinton email matter has already been investigated by the Justice Department, even if Republican partisans may not have liked the outcome.

Tony Podesta’s activities are already a subject of inquiry by special counsel Robert Mueller, which is why Podesta just resigned from his own lobbying firm. So Trump’s inclusion of Podesta in his broadside manifested either a scarcely credible ignorance of the state of play in an investigation with which Trump is plainly obsessed, or a willful attempt to deflect attention from Mueller’s focus on Trump campaign affiliates.

And, as multiple credible observers have explained, the Russia-uranium-Clinton connection is an invented nonstory. Jeffrey Lewis, a nuclear materials and nonproliferation expert, observed in Newsweek, “I have to say that this is one of those things where reasonable people cannot disagree: There just aren’t two sides.”

In short, every item on the laundry list of things for which Trump wants the Justice Department to investigate his political opponents is either not a crime, has already been or is being investigated—or in the case of the Clinton-uranium “scandal,” is an invented storyline promoted by Trump and his supporters to divert attention from Robert Mueller’s investigation.

Third, it is not necessary to establish impeachable misconduct that a president succeed in bending law enforcement agencies to his corrupting purpose. While some of the law enforcement and intelligence officials Nixon tried to enlist in his illegal schemes cooperated, many refused or ignored his orders, the IRS, the CIA, and important elements of the FBI among them. His failed attempts to misuse federal agencies were nonetheless integral components of the impeachment case against him.

This is a key point in the present case. If pressed, Trump will no doubt claim that he didn’t order anybody to do anything and that his tweets are, at worst, expressions of dismay at the established norm that bars presidents from direct involvement in Justice Department decisions. This is, of course, transparent eyewash. When a president of the United States publicly proclaims that he wants an executive branch agency to do something and will be deeply displeased if it doesn’t, that’s tantamount to an order.

Even if it were not, Trump took the next and fateful step Friday morning when he expressed disappointment in the Justice Department for its inaction and held open the option of firing the attorney general if his wishes were not honored. That is as close to a direct order as a president can give without putting it in writing. Any way you slice it, Trump is telling the Justice Department and the FBI that he wants them to engage in legally baseless, politically motivated criminal investigations.

Finally, it is not, cannot be, an excuse if Trump were to say, Well, even though the uranium story and all the rest prove to be baseless, I didn’t know that. As I so often do, I was just responding to what ‘people are saying.’ As the Nixon articles of impeachment observed, a president has the solemn constitutional obligation to “take care that the laws shall be faithfully executed.” If this duty means anything in the criminal justice setting, it means that presidents shoulder an obligation even more binding than that assumed by their subordinates not to unleash on any citizen the intrusive, life-altering power of federal investigative agencies absent credible evidence that a real crime may have been committed.

Let me be absolutely clear here: No matter how far Trump has warped our collective sense of what is normal or even minimally acceptable in an American president, it is not acceptable for a president either to employ, or threaten to employ, the agents and ministers of the criminal law of the United States against his enemies for political gain. A president who does so engages in precisely the class of misconduct perilous to the maintenance of republican government for which the founders designed the remedy of impeachment.

When and if the political season is ever ripe for enumerating Trump’s “high crimes and misdemeanors” in articles of impeachment, his attempts to corrupt the American justice system should be among those articles.

This article first appeared on the blog Impeachable Offenses.