What the Second Amendment protects isn’t a matter of opinion and abstract line drawing. The Second Amendment by its terms protects the right to “bear arms.” It precludes banning “arms” as a category. Now you can draw lines about what is or is not an “arm” that someone may “bear.” (You probably can’t bear, i.e. carry, a nuclear weapon. On the other hand, the Constitution expressly contemplates private ownership of warships.) But you’re stuck drawing lines with respect to that term. And its hard to draw a line where handguns are “arms” but assault rifles are not.