1. State and local taxation of interstate commerce is unconstitutional.

2. Conflicts between state and federal laws are generally governed by Article VI of the U.S. Constitution.

3. Preemption is a question of fact.

4. All types of speech do not receive the same level of First Amendment protection.

5. The constitutionality of restrictions placed on advertising is determined by using a balancing test.

6. In Case 5.5, the restrictions on political ads, commentary, documentaries, etc., just before an election, were held to be a violation of the First Amendment rights of corporations.