Italians often talk about the difference between “applying” the law and “interpreting” the law, but when they do it’s to describe behavior, not abstract concepts. Interpreting is what you do for friends, a kind of forceful reading of regulation to muscle it into whatever shape you want (at whomever’s favor). Applying is what you do for enemies, in which case the reading is almost simplistic, and all the force is in the application (where every letter lands like a hammer on the intended party).
American style also uses a dichotomy, the spirit and the letter, one which depends on the assumption that somewhere in there is The True, The Just, The Righteous Outcome, and that your reading of the law should always point you in that direction.
Absent that assumption, the assumption of Truth, you enter a world of friends and enemies. It has been interesting to me to watch that assumption disappear so completely from national politics, because once it’s gone it seems impossible it was ever there. Every time Trump (and now McConnell) opens his mouth, he reminds us that what matters most are his friends and his enemies. I laugh a little at his (and conservative and libertarian) invective against the courts, because at this moment the gatekeepers of enforcement feel entirely unbound by either spirit or letter of law, and by their power to selectively enforce, they have become its only real interpreters.
We do not have ethics rules if they cannot be violated. We do not have an emoluments clause if it never goes into effect. There are no dictates if no one will execute them. But so to, the agreement that we submit ourselves to power so long as power submits itself to the rule of law depends on the rule of law.
This is the social contract. These are the conditions of civil obedience. Protest can be legal or illegal, but after a certain point, the question is irrelevant.
In either case it is an obligation.