The court isn't "supposed" to change things, they are supposed to base every decision with regard to the Constitution, therefore base decisions that do not go against it.
Once the rule of law(that living/breathing document you so love to change) isn't upheld, then what do we base the laws of our country on, the will of the currently elected? That is exactly what this country WAS not founded on and we were supposed to fight against.....enter gun law.