He argues, for example, that the King could never have pardoned himself because "being constitutionally incapable of doing wrong, and thus of committing a crime, the occasion for such a pardon could never have arisen." Likewise, Binghamn notes that "while the royal power of pardon was very wide, it was not unlimited" and a commutation of sentence "could be offered subject to a condition which the defendant was free to accept or not." In addition, it was "accepted" that even a full pardon "did not do more than free a guilty person from the legal consequences of his illegal act. It did not give rise to a fiction that the person had committed no offence."
The piece then asks, "what need there now is in [England] for exercise of the prerogative power of pardon or mercy?" After considering - and rejecting - a variety of possible justifications, Bingham concludes a "more persuasive ground" is to be found in changes in "exterior circumstances" that might call for group pardons, or amnesties. In general, he sees "very little scope for the royal prerogative of mercy in Britain today."
On the other hand, Bingham says "the American approach" to the presidential pardon power "highlights highlights the tenacity with which the courts have adhered to an originalist view of the Constitution" and the tendency of lawyers toward "literalness" in Constitutional interpretation. Finally, and most interestingly, Bingham writes:
Third, and perhaps anomalously, the British law on this subject would seem to be much closer than the American to the ideals that inspired the American Revolution. The colonists then rejected what they saw as the overweening, unaccountable, all but absolute, power of the English king, replacing it with a republican democracy governed by law. Yet whereas here the royal prerogative of pardon has virtually withered away, the presidential power survives apparently intact.See Bingham's entire piece here.