That is true, so far as it goes. There is no case law that I know of that combines the 10th, 2nd, and 9th amendments. Lopez says that mere possession of a firearm is not interstate commerce, and the 9th circuit agreed with that in U.S. vs Stewart.
Wickard needs to be reversed. It is an abomination to the Constitution, and reversed many decades of precident.
This is true, and its damage goes far beyond firearms law. Unfortunately I'm not sure even Scalia would be on board this (though he would scale it back). Thomas is probably the only justice who would actually overturn it given the opportunity.
But that possession affects interstate commerce, and such a recitation must appear in the federal law that prohibits handguns w/in XX feet of a school. The Lopez decision was gutted months after its passage. It's holding is facile.