How does this square with broad reaching commerce-regulating state laws like the CCPA or CEQA? Also, for federal supremacy/the Commerce clause to apply to something like this, doesn't the Federal government first have to have legislated in this area?
The reason this is tricky is that Wickard v Filburn is just a terrible, terrible decision. It massively expanded what the federal government can do, without a bright line of any sort to limit it.
These things, imho, are rightfully within the purview of the states to implement. However, should the federal government declare there is a national interest (justification) for national regulation, then per court precedent it would compel the state to change. I do not believe there is any sort of jurisprudence for "grandfathering in" existing state laws. Just as prosecutors have discretion over what cases they actually prosecute, the government may choose to look the other way when state laws overlap the feds jurisdiction.
If they tried, though, the state would still have the recourse of attempting to go before the supreme court, which would involve upending existing precedent. I suspect the current court would be about as favorable towards limiting the interstate powers clause as it gets, but it isn't a given by any means.
