I see some good ideas being suggested, but here's my entry: he can now *commercially* pirate music, since to really be criminal rather than civil, needs to be commercial. So he could set up the White House's official pirate streaming service. And no one could do anything.
Okay, folks, who is putting together the list of the funniest crimes that Biden should be committing between now and election day to highlight the absurdity of today's immunity ruling? Not the stuff like assassinations. Just stuff to make a point.
That doesn’t fit into the guidance outlined in the scotus ruling. The prosecution would easily clear the bar that “cultural benefit” isn’t a core constitutional function of the office.
Though less amusing, I think the answer to the exercise has to be something along the lines of: joining a criminal conspiracy and taking an affirmative step to advance the conspiracy by, e.g., declassifying some relevant information.