FOR THE FOURTH TIME ---- YES!!!
"So now you claim that the Second Amendment means that the federal government cannot infringe that pre-existing right to keep and bear arms unless the keeping and bearing is not related to a militia."
NOW I claim? Like it just happened? I've BEEN claiming that. Where have you been?
Re-stating your opinions with certainty is not a simple task.
Many of us disagree that the grammar of the Second Amendment permits the militia clause to limit the scope of the pre-existing right. You disagree.
It would only be logical then to ask whether you have considered whether you are wrong on this important point.
Previously, I have posted something similar to: "A well-educated electorate being necessary to the preservation of liberty, the right of the people to keep and read books shall not be infringed".
You must then believe that the above statement permits the government to regulated any book which it deems to not be educational. Is that not so? And that Congress has full authority to say which are or are not educational in regulating such books?
Such a reading eliminate completely that there could be any other basis for keeping and bearing books; such as for religious purposes.
The further consequences of such a reading would be that Congress has full power to say which books the people may keep and read. That this is equivalent to entirely eliminating the protection seems to escape you.