Pardons
Steven Calabresi and Norman Eisen write the folllowing in "The Problem With Trump’s Odious Pardon of Steve Bannon: It is corrupt and a possible obstruction of justice and should be legally challenged" (2021):
The pardon of Mr. Bannon, his former chief strategist, encapsulates the most repugnant aspects of Mr. Trump’s misuse of the pardon power: cronyism, criminality and cultivation of his far-right base. One of us is an originalist Republican and the other a living-Constitution Democrat, but we both think pardons like that of Mr. Bannon may be unconstitutional.
And as with previous actions for Roger Stone, Paul Manafort and Michael Flynn, the new pardon of Mr. Bannon is both corrupt and a possible obstruction of justice, as he might otherwise have turned against the former president in a potential criminal, civil or impeachment proceeding. ...
The pardon of Mr. Bannon, his former chief strategist, encapsulates the most repugnant aspects of Mr. Trump’s misuse of the pardon power: cronyism, criminality and cultivation of his far-right base. One of us is an originalist Republican and the other a living-Constitution Democrat, but we both think pardons like that of Mr. Bannon may be unconstitutional.
And as with previous actions for Roger Stone, Paul Manafort and Michael Flynn, the new pardon of Mr. Bannon is both corrupt and a possible obstruction of justice, as he might otherwise have turned against the former president in a potential criminal, civil or impeachment proceeding. ...
Mr. Trump did not have the constitutional power to obstruct justice by failing to faithfully execute the law through pardons of associates like Mr. Bannon, who could potentially testify against him.
Calabresi and Eisen are wrong, though their theoretical point is not ridiculous. Their practical point is. We have no reason to think that Bannon's pardon will prevent him from testifying against Trump. Indeed, we have no reason to think that Bannon has anything relevant to say, or, indeed, any evidence that Trump has committed a crime, or, indeed, any specific crime that has been charged against Trump. It is the purest speculation. But suppose that Trump was currently under criminal trial for sexual assault and we had reason to believe that Bannon was a witness. How is Trump pardoning him supposed to make him a worse witness? To be sure, if Bannon was in prison the prosecutor could dangle a pardon in front of him for cooperation, but it isn't clear whether that would make his testimony more likely to be truthful, or less. And it might be that Bannon would be grateful to Trump for the pardon and prefer to be imprisoned again for contempt of court or perjury rather than testify against him--- but remember, Trump and Bannon fell out, and Bannon is convicted fraudster. Trump couldn't count on Bannon being a nice, grateful, guy. So pardoning Bannon wouldn't be a good way to keep him quiet.
But let's look at it as theoretical point. Suppose President Smith pardons his friend John Doe, who is scheduled to appear as a witness against him in his upcoming trial, and allows Doe to flee to Ecuador, where he can't be compelled to testify. And suppose Smith boasts publicly about how the only reason he pardoned Doe was to prevent him from testifying. Is the pardon valid?
The pardon is certainly corrupt. I think the fact that President Smith pardonned Doe should be admissible at Smiths trial, though I can't say how the courts would rule-- the courts have made such a mess of criminal procedure that perhaps they wouldn't let the jury hear facts like that. President Smith has certainly obstructed justice, and perhaps this even fits the legal definition of that crime, so he should be convicted and punished. But that's not the same as the pardon being invalid. It's similar to when a legislature passes a statute because its members have been bribed. As I recall (tho I might be wrong), the Supreme Court in Georgia v. Peck ruled that an action by the state legislature involving land sales was valid even though it was motivated by bribes. (I forget whether it was a statute or a contract at issue.)
Postscript. Calabresi and Eisen also say,
Recent decisions of the Supreme Court of Britain have held that monarchal prerogatives akin to the pardon power must yield to modern practice. In 2017, the court held that Queen Elizabeth II’s executive power did not allow her to effectuate Brexit by nullifying the treaties by which Britain had joined the European Union — even though traditionally monarchs (and U.S. presidents) have unilaterally abrogated treaties. Then in 2019, the British Supreme Court held that she had acted unlawfully when she attempted to exercise another of her powers by proroguing, or temporarily suspending, a session of Parliament at the request of the prime minister to advance Brexit.
These are just the latest examples of how ancient powers of English monarchs have all been subjected to the rule of law gradually in the past 400 years.
They have it backwards. These are just the latest examples of how the rule of law has been gradually eroded over the past 150 years by violating the ancient rights of English monarchs. The "rule of law" means the rule of law, not the rule of Parliament. Indeed, that is the very issue that caused the American Revolution. Parliament and the King said that Acts of Parliament could override the ancient rights of Englishmen; the Founding Fathers said they couldn't. In practice, of course, Queen Elizabeth II did not exercise her formal right to make treaties, nor has any monarch for many years, but the law never changed. Rather, if Queen Victoria had made a treaty without the consent of Parliament, the Cabinet would have resigned, and she would have found herself unable to govern. Or, if her Cabinet had agreed, most likely Parliament would have been outraged and would have cut off funds for the government. In either case, the treaty would still have been valid. It is modern courts that have abandoned the rule of law.