Aaron Rappaport is a law professor at the University of California Hastings College of the Law.

President Trump’s holiday gift list, news reports suggest, may include broad pardons for his three oldest children and his personal lawyer, Rudolph W. Giuliani, even before they have been charged with any crimes. But if Trump believes such pardons would protect the recipients from federal prosecution, he should think again. In addition to violating core democratic ideals, such a move might well prove beyond his constitutional authority.

Pardons come in many varieties, but the vast majority are issued to individual offenders for specific charges or convictions. Blanket pardons for individuals — such as Gerald Ford’s pardon of Richard Nixon for “all offenses against the United States” — are exceptionally rare. Over the past half-century there is only one other example: George H.W. Bush’s pardon of officials caught up in the Iran-contra affair “for all offenses” within the jurisdiction of the independent counsel.

Both of these pardons were heavily criticized at the time, and with good reason. A blanket pardon inevitably hides from public scrutiny what is being immunized, undermining accountability. It offers the opportunity for unscrupulous presidents to protect friends and accomplices from the reach of the law. And it can lead to errors, since the pardon may immunize an offender for crimes beyond the president’s intentions. This is not to say that blanket pardons have no benefits; some believe that Ford’s pardon of Nixon helped the nation move on from Watergate. But the risks of a blanket pardon outweigh the benefits.

Trump, of course, has never been one to concern himself with these niceties. And that raises the question: While blanket pardons are unseemly, are they also unlawful exercises of the president’s pardon power? The pardons for Nixon and the Iran-contra defendants don’t offer an answer, since neither was challenged in court.

Most observers assume that the president is free to issue blanket pardons, believing the president’s power in this area is effectively unlimited beyond the few constraints explicitly mentioned in the Constitution (no pardons in cases of impeachment, or for state crimes). My scholarship suggests that interpretation is incorrect.

In fact, based on the Framers’ original understanding of the pardon authority, the better reading is that, while the pardon power grants the president expansive authority, that power is not unlimited. Most importantly, the Framers would have understood that pardons must be issued for specific crimes. They were not intended to be broad grants of immunity, get-out-of-jail-free cards bestowed by presidential grace.

The Supreme Court has repeatedly affirmed that the scope of the pardon clause should be interpreted in light of its meaning at the time of the founding. This originalist methodology means looking to 18th-century English law. As the court said in an 1855 case, “when the words to grant pardons were used in the constitution, they conveyed to the mind the authority as exercised by the English crown, or by its representatives in the colonies. At that time both Englishmen and Americans attached the same meaning to the word pardon.”

That meaning included what might be called a “specificity requirement” — a pardon would be deemed valid only if it identified the specific offenses to which it applied. As William Blackstone, the leading authority on English law at the time, declared: “A pardon of all felonies will not pardon a conviction.” Instead, the offense “must be particularly mentioned.” Blanket pardons, in other words, were invalid.

Notably, the British king once possessed broader pardon powers, which were curbed starting in the late 17th century. The precipitating event involved King Charles II, who, facing financial difficulties, sent a secret emissary to France to collude with the French king. In return for a large cash payment, Charles agreed to a deal: England would join France in invading the Netherlands. When the details of this collusion leaked, Parliament responded in anger. Although it could not punish Charles directly, Parliament impeached and then imprisoned the emissary. In response, the king pardoned the emissary. When it was all over, several new constraints on the king’s pardon authority were established.

Since English law informs our own understanding of the pardon power, there is a strong argument that the specificity requirement is part of our Constitution and serves as a constraint on the president’s authority. That would not prevent the president from issuing pardons to anyone for any reason, but it does require that each pardoned crime be listed.

In the case of his family and personal lawyer, such a list might prove embarrassing to the president — and edifying to the public. In this way, specificity raises the political costs of issuing such pardons. It also reduces the pardon’s effectiveness. Should a relevant offense be left off the list, the pardon’s recipient would be vulnerable to prosecution.

The Supreme Court has never ruled on the specificity requirement, and the question of the validity of any blanket pardon by Trump would come up only if a federal prosecutor seeks to indict a pardon recipient who raises the pardon as a barrier to prosecution.

But if the issue were to arise, there is a significant possibility that a court, dominated by self-identified originalists, would invalidate the use of blanket pardons. This possibility should make Trump pause before offering such pardons to friends and family. But it also leaves him in a bind. Should he attempt to specify each and every federal crime committed by his children or lawyer? Or is that a gift too costly even for Trump to consider?

Can the president pardon himself? Legal expert Randall D. Eliason answers key questions in the Mueller investigation. (The Washington Post)

Read more: