Now that the House of Representatives has impeached President Trump for a second time, this time on an allegation of inciting insurrection against the U.S. government, the potential consequences for his words and actions are becoming clearer. He might be convicted in the Senate and disqualified from holding future federal office. Aside from the Senate trial, he might also be tried in federal court on a range of charges related to the attack on the Capitol.

All of this once again raises the question: Can he pardon himself? He tweeted in 2018 that he had the right to do so, but does he?

Not according to the words, history or structure of the Constitution. In fact, such an action would erode foundational legal principles in our republican form of government. No person can be a judge in his own case. Nor is the president, unlike an absolute monarch, above the law.

Article II of the Constitution gives the president “Power to grant Reprieves and Pardons for Offenses against the United States, except in Cases of Impeachment.” A “pardon,” issued from a properly vested governmental authority, relieves a person of the legal consequences of a criminal act. The power was borrowed from England, but as with many constitutional concepts, it has been adapted to the distinctive American context and does not even apply to state crimes.

While the power is broad, it is not unlimited. For example, in Ex Parte Garland (1866) the Supreme Court interpreted it to apply only after the underlying offense has been committed. The main reason for King James II’s forced abdication, after all, was his attempt to exercise a power of suspending the laws. Even the royal pardon power did not encompass a license to disobey all law.

But American constitutional principles go further, confining executive power in ways that would have been alien to a monarchy. For example, an English sovereign’s term was lifelong. A king could not be prosecuted, so the question of self-pardon never arose. By contrast, the president is an executive for a defined term and enjoys only limited powers that are constrained by law, a written constitution and the other branches of government. A president is not immune to criminal prosecution after leaving office.

Some of the Founders worried about creating a kinglike pardon power. For example, if the president could hypothetically pardon his associates for treason (which is impeachable), Edmund Randolph warned the 1787 Constitutional Convention that “the president himself may be guilty. The Traytors may be his own instruments.” James Wilson reassured the delegates that “if [the president] be himself a party to the guilt he can be impeached and prosecuted.” With that assurance, the discussion ended.

Wilson’s reasoning assumed that the president could not pardon himself. It would not have quieted fears if the Founders thought he could simply excuse his own treason. While the delegates in 1787 did not specifically discuss the matter, self-pardons would have been as unimaginable as they were dangerous.

The “power to grant … pardons” is therefore a legal term of art that, in its historical context, should not include self-pardon. The notion grants the president something akin to a monarchical power, a governmental form against which the very founding of the United States was a rebellion.

The concept of the self-pardon also violates other foundational principles of the laws on which the country is based. Justice Chase wrote in Calder v. Bull (1798), "[Regarding] a law that makes a man a Judge in his own cause … [i]t is against all reason and justice, for a people to entrust a Legislature with SUCH powers; and, therefore, it cannot be presumed that they have done it.” In Federalist No. 10, James Madison contended, “No man is allowed to be a judge in his own cause, because his interest would certainly bias his judgment, and, not improbably, corrupt his integrity.” On this basis, the Office of Legal Counsel concluded in 1974 that the president cannot pardon himself.

Self-pardons are a particularly noxious form of self-dealing that undermine the rule of law itself. As Chief Justice John Marshall wrote in Marbury v. Madison (1803), the Constitution makes the United States “a government of laws, and not of men.” Not even a president is above the law.

Finally, there is an explicit textual limitation on the pardon power specifically relevant to Trump. Pardons cannot be granted “in Cases of Impeachment.” The dominant interpretation of this Impeachment Exception Clause is that it only prohibits a president from obstructing the impeachment process or shielding an impeached official from the consequences of a Senate conviction (e.g., removal from office and disqualification).

But might the Impeachment Exception Clause also be understood as barring an impeached president from pardoning himself? The Constitution says that an impeached official, including the president, can “be liable and subject to Indictment, Trial, Judgment, and Punishment” after Senate conviction (Art. I, Sec. 3).

Whatever the president’s power to shield other impeached officials from criminal prosecution, the best reading of the Impeachment Exception Clause is that he should not be allowed to pardon himself. Here’s why: The president is sui generis in our constitutional system. He is entrusted with mighty powers and unique obligations. The president “shall ’take Care that the Laws be faithfully executed.” (Art. II, Sec 3) Yet impeachment calls into serious question his ability to do so.

While the executive pardon power is broad, the Impeachment Exception Clause could be understood in a correspondingly broad way to provide a check on the president’s license to escape the consequences of his own lawlessness. This textual limitation on the pardon power could be interpreted as consistent with the Constitution’s structure, because it would reinforce the separation of powers among the three coequal branches. It would prevent the president from avoiding a Senate trial and future ramifications in legal proceedings overseen by the judiciary.

Trump’s conduct involves a “Case of Impeachment” (regardless of whether he is convicted by the Senate), and thus it would be excepted from the executive pardon power.

Let’s hope the president does not try to pardon himself. If he does, he may never be prosecuted, so the self-pardon may not be tested.

If he is prosecuted, the president has other possible defenses. But if our Constitution and legal traditions are followed, he should not be allowed to plead, “I beg my pardon.”

Editor’s note: A previous version of this post stated that the reason for King James II’s abdication was an attempt to exercise a power of anticipatory pardon, but the text has been updated to reflect that he was forced to abdicate for attempting to exercise a power of suspending the laws.