Dormant Commerce Clause Today

If there is pure economic protectionism at work (e.g., facial discrimination), state regulation is prohibited, unless the state can show no other way (or no reasonable alternative) to achieve a legitimate state interest.
If an even-handed effect on intrastate and interstate commerce, and effects on interstate commerce are incidental, statute allowed unless burdens on interstate commerce clearly excessive in relation to local benefits.

To what extent does state regulation undermine the purposes of Congress’ Commerce Clause power?
- The goal of a truly integrated country in which states are working together.
- The goal of a well-functioning national economy.

Privileges and Immunities Clause of Article IV

Does the law burden an Art. IV privilege or immunity (i.e., is the out-of-state resident’s interest in the state’s privilege sufficiently fundamental to the promotion of interstate harmony)?

Does the state (or municipality) have a substantial reason for its discrimination, and is there a close relationship between the reason and the degree of discrimination?

Supremacy Clause

This Constitution, and the Laws of the United States which shall be made in Pursuance thereof . . . shall be the supreme Law of the Land . . . .

Article VI, § 2

Preemption

•Congress expressly states its intent to preempt state law (express preemption)
•State law imposes obligations that are inconsistent with the obligations of federal law or that interfere with the objectives of federal law (conflict preemption)
•State law regulates in an area that Congress intended to occupy entirely with federal regulation (field preemption)