Whether Arizona's order burdened interstate commerce even though it regulated the packing of cantaloupes before their interstate shipment.
Holding
Yes. The order directly affected and burdened interstate commerce because it prohibited the company's planned interstate bulk transportation and compelled processing to occur in Arizona rather than California.
Reasoning
Arizona argued that its order governed only intrastate packing before commerce began, relying on cases that allowed Mississippi to tax cotton stored and processed within the State before its ultimate sale. The Court found those precedents inapposite. In those cases, the cotton had come to rest in Mississippi and had no definite out-of-state destination when taxed; Bruce Church's perishable cantaloupes, by contrast, were destined immediately upon harvest for a known packing facility in California.
The order did more than regulate an operation occurring within Arizona. Its practical effect was to require that an operation Bruce Church had efficiently performed in California instead be performed in Arizona. Accepting Arizona's theory would insulate state laws that require processing to occur in the home State before goods may be sent to another State, a form of regulation the Court had consistently invalidated under the Commerce Clause.