Earlier quoted context omitted.
It's extreme to the point of silliness. If a court decides that would fall under "official acts", we are already doomed.
You know the majority can read the dissent right? If they felt it so silly they could have addressed it. Rather than contesting the claim they dismiss it because they feel its not as likely as other (seemingly non-mutually exclusive) concerns: > The dissents’ positions in the end boil down to ignoring the Constitution’s separation of powers and the Court’s precedent and instead fear mongering on the basis of extreme…
> The dissents overlook the more likely prospect of an Executive Branch that cannibalizes itself, with each successive President free to prosecute his predecessors, yet unable to boldly and fearlessly carry out his duties for fear that he may be next. ... Virtually every President is criticized for insufficiently enforcing some aspect of federal law (such as drug, gun, immigration, or environmental laws). An enterprising prosecutor in a new administration may assert that a previous President violated that broad statute. Without immunity, such types of prosecutions of ex-Presidents could quickly become routine.
Their argument isn't that it's not likely, it's that there's another failure mode that is even more likely.