While Gorsuch has his own peculiar agenda, it is fair to assume that Roberts and Barrett see Trump as a talented and well-meaning but petulant child who needs to be disciplined occasionally for his own good. Will Trump accept his loss with that spirit?
Of course not! He has already imposed new, temporary tariffs under a different statute and will try the national security route as a permanent fix. Look for him to do everything in his power to avoid giving refunds and to grossly misuse his national security authority, which will lead to more litigation and uncertainty, lower growth, and unnecessary trouble for the GOP.
The most important result of the decision is that it deprives Trump of his ability to use tariffs for purely personal and capricious reasons. Nothing says you’re the boss like the ability to tax people just because they did something to piss you off that morning.