can't his concessions come back to bite the overall movement towards full, original intent implementation of the 2nd Amendment?
No. Legal arguments are based on the law, not based on arguments... which is why rhetorical arguments have no weight. Such concessions are clearly made only to further a legal argument which only becomes law if it finds its way into a holding/opinion. And if such concessions find their way into the holding it will not be because Gura conceded them here (which he only did with qualification) but because such concessions reflect that actual state of the law as it exists today across this nation. To hold otherwise is to demand the abrogation of those laws and it is unlikely any court, much less SCOTUS, will do that.
If Gura had NOT made such concessions, beyond broadening the scope of his argument he would be showing himself to be out of step with the legal landscape of this issue which would discredit his core argument all the more.
Even if you think any registration is per se unconstitutional (1) That's not your case (2) That's not the present legal reality since registration laws exist with a presumption of constitutionality. So you fight your battles one at a time. Just like discrimination, you don't get baited into saying Separation is per se unequal/unconstitutional no matter if you believe so in your heart of hearts until you've established that your present situation is unequal even under the current legal regime. No one used those early concessions as legal fodder to argue against them during Brown because they have no legal weight.
You could claim insincerity, a changed mind, an inconsistent argument... but these are irrelevant before the law. And that's why what the justices do is important, it's beyond the passions of one man, the arguments of a single advocate, or the integrity of any individual... it's instead based on rules meant to be insulated from those things, which gives it moral force to change public opinion.
Put another way, RKBA rhetoric has been perfected and reiterated endlessly in the last few decades in response to gun control legislation... but the question is how many minds has it changed? It may have sharped the rhetoric of some, swayed a few on the fence, converted the odd Saul of Tarsus here and there, but it's largely just polarized noise that both sides sling at each other. However the law, even from a political court, still has an impartiality to it that changes minds. Even for trivial things like seat-belts or major things like discrimination. But to change minds you have to start where people are. And where we are right now is that most jurisdictions have controls on guns that their elective representatives put in place as a reflection of the will of the people. The vast majority of Americans believe in some control. That is a mindset that has to peeled away, not stripped away by force resulting in political blow back.
First you get people to recognize the 2nd at least in legal terms is as important as the 1st or any other right. Then people start to see the moral and practical side of things. Then the laws will change accordingly and with legitimate founding in a way that can't be swept away by a future politicized court.
