First let me say that I am no expert in Constitutional Law, but I think I can safely say that, once again, the MSM has missed the boat on the SCOTUS ruling on Presidential immunity.
First of all, it is not "Trump Immunity," right now that "umbra of immunity" applies to Joe Biden.
Trump himself seems to think (only having read summaries of the MSM) that the ruling is a "Get Out of Jail Free" card for the felonies of which he was convicted. Nope. He wasn't even President when he committed those felonies, therefore no Presidential Immunity.
In the same way it does nothing to protect him from the documents charges. There might be some kind of argument that actually boxing up the documents was an "official act" of the President, but not returning them and obstructing the FBI (as a private citizen) would seem to be logically beyond the scope of the immunity.
Even the January 6th charges are probably not covered by the immunity put forth by the Court. It would seem hard to imagine how even this Court could backflip it's way to saying that immunity extends to people running for President.
This would be actually insane to grant private citizens running for President (anyone over the age of 35 and natural born citizens) "Presidential Immunity." If campaigning for President gets me immunity, I can shoot my opponents on the debate stage.
So, campaigning for President is not an "official act" of a sitting (or former) President. Also, the President has no official role in conduct of elections (that is a state matter) or certifying the results. Therefore, again, logically the charges relating to January 6th are most likely not "official acts" and certainly don't cover the charges in Georgia and any others that are brought by other states.
This is not, as many seem to think, a power grab for the Presidency, but rather a power grab by SCOTUS.
In a heartbeat they could decide that some thing Biden did was not an "official act" and some prosecutor could charge him.
What Trump doesn't seem to realize is that the same applies to him as well. Granted SCOTUS does have some kind of ultimate authority, but with this ruling, the President hangs by a thread. Maybe something will be an "official act" maybe it won't. This opens of the possibility of some rogue prosecutors charging sitting Presidents with all kinds of stuff arguing it was not an "official act."
If Trump loses the favor of Harlan Crowe and company, SCOTUS might be like, "Nope, not official, off to jail with you." More worryingly it could happen to Joe Biden tomorrow.
This is where SCOTUS has made us a Banana Republic. They will decide whether the President stays out of jail -- this time! They will decide whether the "science" behind a regulation is any good. They will decide what you can have for breakfast for tomorrow. They will decide how many motorhomes and vacations they can accept.
And they will be free to change their minds at the drop of a hat, we already know that precedent means nothing to these destroyers of our Constitution.
And once they have taken this power unto themselves we can guess what happens. In pretty much every fascist regime, lots of people think they are on the side of the strongman. Then the purges come and they find out they are wrong.
At this moment, Trump thinks he is the strongman, but in many ways it is SCOTUS that has, perhaps temporarily granted him the "strength." Alito and Thomas could turn on him in a heartbeat.
In the same way they have already turned against our Constitution and the rule of law.