Presidential pardon immunity is unreversable. There could potentially be a constitutional amendment on this, which is a super high bar, but even then the prohibition on ex post facto laws would only affect pardons going forward. It will be up to the states.
>>the prohibition on ex post facto laws would only affect pardons going forward.
That is plainly wrong. A constitutional amendment can say anything. There are no prohibitions.
> Presidential pardon immunity is unreversable
But presidents are also immune against prosecution for official acts. Could a president just disregard pardons from a prior administration? Immovable object, irresistible force kinda situation right?