> California can't restrict the importation and sale of items manufactured legally in other states if the item itself (after manufacture) is safe.

I'm not sure about that, maybe it is based on the definition of "safe". There are tortilla chips made in Chicago that explicitly say they cannot be sold in California on the packaging. This is due to chemicals banned in Prop 65.

https://www.reddit.com/r/mildlyinteresting/comments/1220zn9/...