Part of the ruling was that conversations between DOJ and President constitute the President's official duties and "therefore" (per the three judges appointed by Trump, one who expressed sympathies with Jan 6 rioters, and yet another whose wife was an active endorser and planner of aspects of the coup) those conversations are protected and cannot be entered as evidence in a criminal proceeding against the President.

The more insidious outcome is that the President can now, because these conversations are official, officially order the AG to investigate and prosecute political opponents.

Maybe some court can review it on down the line, years later. Given the number of judges appointed by Trump, maybe not. Either way, the federal government and rule of law was massively, severely crippled yesterday by the Supreme Court