Well, no, it’s in the US Constitution. So I suppose congress could add a constitutional amendment to remove the prohibition on ex post facto laws. But that’s so unthinkable it might as well be a fantasy. Far from “plainly wrong,” which seems unnecessarily aggressive verbiage.

An amendment can’t violate the constitution. It is the constitution. You can do anything.

Why couldn't the amendment just say, "The presidential power pardon is revoked, and all prior pardons are null and void"? You have to amend the Constitution to remove the pardon power regardless, why would it be so difficult to put in a clause saying that it's retroactive?