Will Baude has a great post up about the Heller case, which makes an important point about both the Second Amendment and originalism. Will writes:
It seems to me that most of the work in Heller is done by an interpretive claim that is as much legal or theoretical as it is historical. This is the majority’s claim that “the Second Amendment was not intended to lay down a novel principle but rather codified a right inherited from our English ancestors,” and that even if self-defense was not the primary purpose of “the right’s codification; it was the central component of the right itself.” The idea here is to see the Second Amendment as framed against a vast pre-existing backdrop of non-constitutional legal rules, including the right to keep and bear arms. The Second Amendment plucks one of those pre-existing rules and codifies it against future change.
Now one could certainly disagree about that move. Some people think that legal rules should be limited to the paradigm cases or purposes that motivated their enactment. But I think the move is correct. If the Takings Clause began by telling us that it was primarily motivated to stop the uncompensated impressment of horses and guns by the army, we should still read “private property” consistent with its natural and traditional scope. In any event, once that move is established, most of the history described by the dissent is beside the point.
This is a recurring theme in originalism debates. Often what seems like an intractable historical debate is really solved by a legal or interpretive question about what kind of history matters.
This is especially true as to the Second Amendment, because so much of the Bill of Rights was about protecting the traditional rights that the Americans believed they possessed. Some constitutional provisions attempt to preserve existing rights, some attempt to reform the law. The Bill of Rights is mainly about the former. Under this view, the purpose of the provision fits neatly with the meaning of the legal words.