I don’t think Scalia has gone over the other side here. There obviously has to be some clarification of what a US citizen can and cannot own in the way of “arms”.
I don’t think anyone believes a citizen should be able to own a fully armed tank or fighter jet. What about 50 caliber machine guns and hand grenades, tank killer missiles? The legal battle will be fought where they’ve been for years already: automatic or semi-automatic, hand carried rifles, clip size, caliber, etc.
No, but states should have their own armed forces not under control of the President. The Governors should have their own state militias if their states want them.
Congress have no power to disarm the militia. Their swords, and every other terrible implement of the soldier, are the birthright of an American...[T]he unlimited power of the sword is not in the hands of either the federal or state governments, but, where I trust in God it will ever remain, in the hands of the people."
Tenche Coxe, The Pennsylvania Gazette, Feb. 20, 1788.
That's what one of the founders thought.
You've already limited your argument to the very-limiting term "firearms."