There are two elements to the immunity decision that are particularly extreme in a way that many will miss: (1) motive is irrelevant and (2) immune acts are not just excluded from prosecution, they’re excluded from evidence.
/1
/2 Motive being irrelevant means that the President can do a thing for expressly lawless reasons so long as the thing is within the extremely broad range of official acts. So question isn’t “can the President conspire to defraud,” it’s “can the President call a state official about an election.”
/3 The problem is that almost anything can be shoehorned into an official act depending on how you characterize it or the level of generality you use. The Court’s “well of course a President has to use due care that election laws are enforced” hints at this.
/4 More powerful, to a trial lawyer, is the prohibition on the use of immune acts as evidence. In almost every other context (save Speech & Debate), you can use things as evidence when you can’t prosecute for them. If I say “this man must die,” that’s usually protected by the First Amendment ….
On this point, even Justice Barrett thought that the fascism went too far. She didn't join that part of the opinion, which still is the law of the land because (shamefully) Chief Justice Roberts, Justice Thomas, Justice Alito, Justice Gorsuch and Justice Kavanaugh imposed it without any legal basis.
