Does the duly elected government of California have a right to set environmental standards within the state's bounds?
Looser standards may in fact harm persons outside the jurisdiction and might be challenged, at least on principle. Tighter standards don't.
From my class room memories(a long time ago) states could have stricter laws than the Feds but not more lenient. But, if my memories are correct then I wouldn't think recreational marijuana laws would stand.
The Uniform Commercial Code (UCC), first published in 1952, is one of a number of Uniform Acts that have been established as law with the goal of harmonizing the laws of sales and other commercial transactions across the United States of America (U.S.) through UCC adoption by all 50 states, the District of Columbia, and the Territories of the United States.
While largely successful at achieving this ambitious goal, some U.S. jurisdictions (e.g., Louisiana and Puerto Rico) have not adopted all of the articles contained in the UCC, while other U.S. jurisdictions (e.g., American Samoa) have not adopted any articles in the UCC. Also, adoption of the UCC often varies from one U.S. jurisdiction to another. Sometimes this variation is due to alternative language found in the official UCC itself. At other times, adoption of different revisions to the official UCC contributes to further variation. Additionally, some jurisdictions deviate from the official UCC by tailoring the language to meet their unique needs and preferences. Lastly, even identical language adopted by any two U.S. jurisdictions may nonetheless be subject to different statutory interpretations by each jurisdiction's courts.
UCC applies to contracts and such, not regulations.
CA has circumstances to show cause behind their actions. Car companies can build cars that don't meet those standards and sell them elsewhere, they just choose not to.