The other huge problem is that the Second Amendment originally acted as a prohibition only against the Federal government, not the States. Under an originalist interpretation, States were free to completely ban firearm ownership, if they wanted to. Only after the incorporation of the Bill of Rights did the Bill of Rights become operable against the States.
Its a tangled issue for sure.
In a sense this is correct, but in light of the actual history it's a little off the mark. That's because all the states already recognized it as a fundamental right of free men, codified in the various state constitutions. Their concern was that the new Federal Government would some day seek to interfere with that fundamental right, thus the states all demanded a Second Amendment be placed in the Bill of Rights to prevent that from happening.
The Federalists tried to explain to those concerned about this issue that the new Federal Government was not being delegated any power over such matters to start with, and never would be in the future, so didn't need an explicit protection of this right. But while those concerned about this question agreed with that premise, they felt they could never be completely sure how the US Constitution might be disingenuously "interpreted" in the future, so they demanded this extra measure just to be sure.
