The whole idea of pardons is to leave some leeway in the system to correct the occasional injustice that will arise from the rigid application of the law. When laws systematically produce unjust results, such as, arguably, our immigration laws do on a regular basis, the correct remedy is to change those laws. But when basically sound and just laws produce the occasional unjust result, as they will because no system of law can account for every real-world situation, that’s when pardoning the victim of the rigid applicaiton of the law is a sound and necessary feature of any legal system.
Now, because the fundamental nature of the pardon power is that it reverses the judgement of the legal system, it follows that a pardon cannot be reviewed by the legal system, and have the pardon reversed because the legal system determines that, no, the pardoned person really did the crime he’s been convicted of, and that, no, his punisment for that crime is not unjust. While the Constituion does not say explicitly that pardons cannot be reviewed by anyone else, it has been taken as implied by the concept itself that there is an almost categorical prohibition on such review, that a presidential pardon has to be allowed to stand no matter what.
I don’t think the pardon power actually is absolute, with any particular pardon categorically free of any possibility of review. A president who could be proven to have granted a pardon for a corrupt purpose could have the pardon declared null, but it would be quite difficult to prove corrupt intent in such a case. The president could claim in his defense in such a case, that it was his judgement that injustice had been done to the person who was pardoned, and no amount of evidence or argument to the contrary, that the pardoned person actually had done the crime and deserved his sentence, can reasonably be entertained. What you would have to prove to get a justified reversal of a pardon isn’t that the pardoned person really was guilty and deserving of punishment and so no reasonable person would have pardoned him, you have to prove that the president had some corrupt purpose and intent in pardoning. How do you prove a state of mind, an evil intention or motive, if you aren’t even allowed to use the lack of any good or sound alternate motivation as evidence?
Now, it is possible that in this case, this particular president, because he suffers from dementia, is creating evidence of corrupt intent, direct evidence of his state of mind and his inner intentions. One reason that conventional politicians speak carefully and cautiously is precisely that openly expressed intentions can create such direct evidence in cases in which courts would not allow themselves to infer from external evidence indirectly back to corrupt intent. One important factor in getting Trump’s travel bans thrown out by the courts, is precisely that he made public statements of religious and ethnic animus towards Muslims and Arabs as the rationale for the ban, and the law disallows official actions taken with that motivaiton and rationale. It’s dollars to doughnuts that, as he discusses this pardon possiblilty with all and sundry (discussions with his lawyers would probably be protected from review), Trump is not being at all careful to refrain from expressing the frank interest he has to protect himself from the discovery of his own criminal activity. He’s not pretending to make this about correcting unjust results of the system, but purely about obstruction of justice as its processes close in on him. If he remains true to form, I expect that media coverage of pardons will have him soon put on public record, in the form of a series of tweets, exactly this point, but he probably already has blabbed frank, direct expressions of corrupt intent to people who could be compelled to testify.
Maybe we need pardons and reprieves because no system is going to always create just results. But putting that power in the unreviewed hands of the president is an obviously bad idea. If followed categorically, the idea that pardons cannot be reivewed would allow the president to create a corps of henchmen free to carry out his will in complete disregard of the law. As a less extreme, but still highly undesirable result, it would create cases such as the one we have before us now, in which president Trump seems to be at least contemplating the abuse of the pardon power to put himself beyond the reach of the law. If he weren’t demented, if he were careful to not blab corrupt intent directly, he could probably get away with it, because the whole point of the pardon power is to allow for judgments that end-run around the judgments of the legal system. Even if there is no categorical principle that pardon decisions can in no way ever be reviewed and reversed, any court would be compelled to bend over backwards to grant something close to such categorical immunity from review. There would have to be a frank, direct admission by the president that the pardon was granted for a corrupt reason. Only demented presidents would make such an admission. We won’t go on forever having all our corrupt presidents also possess the saving grace of being demented.
Add this to the many favors Trump has done us, the many aspects of our system that need reform that his behavior has highlighted so dramatically. We need to pass laws extending current ethics rules (at a minimum -- we also need such rules tightened for all public servants) to the president, and we need an amendment to take the pardon power away from any one person.