Con Law IThe Dormant Commerce Clause and State Power

Discrimination Against Interstate Commerce

The Court reads the Commerce Clause to limit states even when Congress is silent: a state law that discriminates against out-of-state commerce is virtually per se invalid unless no other means can serve a legitimate local purpose (City of Philadelphia v. New Jersey, 1978; Maine v. Taylor, 1986).

Not started Jump to practice

The Commerce Clause is written as a grant of power to Congress. But since Gibbons the Court has also read it as a silent limit on the states, even when Congress has not acted. This "negative" or dormant Commerce Clause stops states from building walls against one another's trade. You know from Preemption that Congress can override state law; the dormant clause asks what states may do when Congress is silent.

Why it works

Why read a limit into a grant? The main reason is the history: under the Articles of Confederation, states taxed and blocked each other's goods, and the Constitution was meant to create a national common market. Hamilton described those trade wars in Federalist No. 22, and Madison in Federalist No. 42. A second reason is political: a state that discriminates against out-of-state businesses burdens people who cannot vote in that state, so its own political process will not correct the harm. The doctrine has critics, too: Justices Scalia and Thomas argued it has no basis in the text and that Congress, not courts, should police state trade barriers.

Key idea

A state law that discriminates against interstate commerce, favoring in-state interests over out-of-state ones, is virtually per se invalid unless the state shows a legitimate local purpose that cannot be served by nondiscriminatory means (City of Philadelphia v. New Jersey, 1978; upheld in the rare case Maine v. Taylor, 1986).
Discrimination against interstate commerce gets review much like strict scrutiny: a legitimate purpose and no nondiscriminatory alternative.

Worked example: The rare law that survives: Maine v. Taylor (1986)

Maine banned importing live baitfish from other states. Why did this discriminatory law survive?
  1. The law discriminated on its face: in-state baitfish could be sold, imported ones could not.
  2. Maine showed a legitimate purpose: out-of-state baitfish could carry parasites and nonnative species harmful to Maine's wild fish.
  3. Maine also showed that no adequate test or inspection could screen the fish, so no nondiscriminatory alternative existed.

Answer: Upheld. The test is hard to pass, but not impossible when the state proves a real difference and no other means.

Worked example: Discrimination in effect

A state requires all milk sold there to be pasteurized at plants within five miles of the city center. Every plant within that radius is in the state. The law does not mention other states. Is it discriminatory?
  1. On its face the law is neutral: it names no state.
  2. In effect it excludes all out-of-state processors, the way an outright ban would.
  3. The state could protect health by inspecting distant plants, a nondiscriminatory alternative.

Answer: Discriminatory in effect, and likely invalid. Courts look at purpose and effect, not only the words.

Common mistake

Looking for discrimination only in a law's words. Laws neutral on their face can discriminate in purpose or effect. On the other hand, remember that some justices reject the doctrine entirely as lacking a textual basis. Check: who bears the burden and who gains: in-state or out-of-state interests?

Congress can always change the result: because the clause is a grant of power to Congress, Congress may authorize states to do what the dormant clause would otherwise forbid. The next lesson covers laws that do not discriminate: Pike balancing.

This is an educational course, not legal advice.

Practice

Pass with 3 right answers, the last 2 in a row. Each right answer earns 3 XP.

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