For the first time in our history, a president has been impeached by the House of Representatives for conduct not alleged to be a crime. (The impeachment of presidents Andrew Johnson and Bill Clinton, as well as the impending impeachment of President Richard Nixon, all involved alleged crimes, while some of the additional articles of impeachment did not.) Against President Donald Trump, a majority in the House approved two articles of impeachment: one for "abuse of power" and one for "obstruction of Congress." Neither article states a crime or statutory violation. Neither article contains elements against which proof of violation can be ascertained.

Our question here is not whether Trump should be impeached, but rather whether Congress is correct to address that question without resort to any clear standard or uniform principle. What is deemed sufficient for presidents we dislike will inevitably provide the standard for impeaching administrations that we favor. There needs to be some objective, nonmalleable standard of misconduct lest, especially in today's polarized environment, impeachment becomes too easy a vehicle for the party in control of the House to hobble an administration of the opposing party over partisan differences.

Article II, Section 4 of the Constitution authorizes impeachment for "Conviction of Treason, Bribery, or other high Crimes and Misdemeanors." Since treason is a crime defined by the Constitution, and bribery was a well-established offense under English common law, under standard principles of interpretation, "other high Crimes and Misdemeanors" would share at least the feature of a criminal offense. At the Constitutional Convention, treason and bribery were considered too limited in scope and George Mason suggested adding "mal-administration," which James Madison objected was "so vague a term [as to be] equivalent to tenure during the pleasure of the Senate." In its place, the Convention settled on "other high Crimes and Misdemeanors."

Although the matter has been contested ever since—and as noted, there has until now been no presidential impeachment without a crime—the prevailing view is that impeachment does not require an indictable offense; rather, the "other high Crimes and Misdemeanors" formulation is thought to invite a broader canvas of English common-law precedents, including abuse of authority, abuse of the people's trust, or even gross dereliction of duty.

One problem with the prevailing approach is that the English precedents do not themselves yield a clear set of principles capable of deterring abusive resort to impeachment. Indeed, as Sir William Blackstone observed in "Commentaries on the Laws of England," "mal-administration of such high officers, as are in the public trust and employment" was "the first and principal" high misdemeanor punishable by parliamentary impeachment. Thus, the very technique of interpretation urged by commentators leads to us to a ground for impeachment specifically abjured in the Constitutional Convention debates.

The noncriminal-offense interpretation is also difficult to square with other constitutional text. The Constitution refers to impeachment seven times—references which taken together suggest a legal proceeding to try a criminal offense: (1) the Impeachment Clause's reference to "Conviction" for "high Crimes and Misdemeanors"; (2) the Senate's power "to try all Impeachments"; (3) the fact that the chief justice shall preside when the president is "tried"; (4) the exclusion in the jury trial guarantee for "all Crimes, except in cases of Impeachment"; (5) the pardon clause granting the president the power to "Grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment"; (6) the requirement that two-thirds of the Senate vote for a person to be "convicted" of an impeachable offense; and (7) the provision limiting the reach of "Judgement in Cases of Impeachment … to removal from Office." Wherever the Constitution refers to "crimes" or "offenses," the reference is to criminal offenses. Nowhere are such terms used to refer to noncriminal conduct or conduct that could be proscribed without a basis in a preexisting prohibition.

The foregoing suggests a textual basis for an objective standard that constrains the political impulse to misuse impeachment and is consistent with the past practice of presidential impeachment: a minimum required allegation that the president violated some established law, whether common, statutory or otherwise. (By contrast, Article III judges enjoy tenure only "during good Behavior," a broader standard not limited to violations of positive law.)

A distinct virtue of requiring a crime for impeachment is that the House is compelled to have a legal basis for bringing an impeachment that would be consistent with how the particular criminal offense is generally interpreted and applied. If, for example, the House believes Trump solicited a bribe, it should have to make this case within the confines of the federal criminal offense of bribery, not by resorting to the vaguer "abuse of power" approach of the House's articles of impeachment. Similarly, if the existence of a legitimate motive (say, Trump's general concern with Ukraine corruption) is deemed not to negate the presence of an illegitimate motive (securing political dirt on a rival), the dual-motives issue should be addressed in a manner consistent with federal bribery jurisprudence, not fashioned ex nihilo.

At the time of the nation's founding, there might have been a chance that not all cases of presidential misconduct would be covered by existing federal law, and hence might, in theory, require resort to English common-law precedents (in fact, for Justice Joseph Story, resorting to English common law was in part a functional necessity given the relative dearth of U.S. law at the time), but today that concern is obsolete. If there are instances of presidential misconduct that are not at the time of their commission proscribed by criminal or other positive law, this problem can be minimized prospectively by appropriate legislation, as has occurred with respect to judicial misconduct.

Samuel Estreicher is Dwight D. Opperman professor of law and co-director of the Institute of Judicial Administration at NYU School of Law. Christopher S. Owens is a 3L at NYU Law. A longer version of this article previously appeared in Justia Verdict and is republished here with permission.