To avoid sales to minors, a Maine state law required retailers to insure that tobacco products were delivered by a carrier that would verify the age and identity of the buyer. Another law prohibited a carrier from delivering tobacco products if they were purchased from an unlicensed retailer.
UPS stopped deliveries, and several associations convinced the First Circuit to hold that the state laws were preempted by the Federal Aviation Administration Authorization Act of 1994, which prohibits a state from enforcing a law "related to a price, route, or service of any motor carrier," with respect to the transportation of property.
On 2/20/08, the Supreme Court agreed. It ruled that Maine's law was preempted because it directly affected motor carrier services and had a significant adverse impact on the objectives of the federal law. The state law would regulate a significant aspect of a motor carrier's business, creating the kind of state-mandated regulations that the federal law was intended to preempt. The fact that the state law is designed to protect health and safety is unavailing, because there is no such federal exception and there are alternatives that do not interfere with carriers that the state can adopt to try to achieve its safety and health purposes.