Commerce Clause

MBEMax wiki article — paired with the Constitutional Law question set on mbemax.com.

One-line summary

Article I, § 8, cl. 3 gives Congress power to regulate commerce with foreign nations, among the several states, and with the Indian tribes — plus the "dormant" negative implication that states cannot unduly burden or discriminate against interstate commerce.

Mnemonic

C-I-S-D — Channels, Instrumentalities, Substantial effects (affirmative); Dormant (negative).

Picture a four-lane highway — Congress can regulate channels, instrumentalities, substantial effects; and it can't be blocked by state protectionism.

Affirmative commerce power (Congress)

Under United States v. Lopez, 514 U.S. 549 (1995) and Morrison, Congress may regulate:

1. Channels of interstate commerce — highways, waterways, internet.
2. Instrumentalities / persons and things in interstate commerce.
3. Activities having a substantial effect on interstate commerce.

Substantial effects — aggregation and economic/non-economic

• Economic activities — aggregation permitted (Wickard v. Filburn; Gonzales v. Raich). Congress may aggregate minor individual activities to find substantial effect.
• Non-economic activities — aggregation limited (Lopez guns in school zones; Morrison gender-motivated violence). Requires a closer nexus and may fail.
• Necessary and Proper Clause — Congress may reach economic activities rationally connected to a comprehensive regulatory scheme.

Limits

• Cannot compel inactivity into activity (NFIB v. Sebelius — individual mandate was not a valid Commerce Clause exercise, though sustained as a tax).
• State sovereignty limits via Tenth Amendment (anti-commandeering).

Dormant Commerce Clause (state action)

When Congress is silent, states may not unduly burden or discriminate against interstate commerce.

Step 1: Does the law discriminate against out-of-state interests?

• Discriminatory in purpose or effect → per se invalid unless the state shows it serves a legitimate local purpose that cannot be adequately served by less-restrictive nondiscriminatory alternatives (virtual strict scrutiny).
• Facially discriminatory: e.g., state banning out-of-state trash.
• Discriminatory in operation: ostensibly neutral but falls disproportionately on out-of-staters.

Step 2: If not discriminatory, apply Pike v. Bruce Church balancing

Incidental burdens permitted unless clearly excessive in relation to putative local benefits.

Market-participant exception

States acting as market participants (buying, selling, hiring for state projects) are not subject to the dormant Commerce Clause and may prefer in-state interests. Cannot impose "downstream restrictions."

Privileges and Immunities Clause overlay (Art. IV, § 2)

State laws discriminating against non-residents in fundamental rights (earning a living, civil-rights access) violate Privileges & Immunities unless state shows substantial reason + closely related means. Different from dormant CC: applies only to individuals (no corporations) and covers only fundamental rights.

NCBE loves to test

• Aggregation. Wickard and Raich allow Congress to aggregate individual economic activity into substantial-effects analysis.
• Economic vs. non-economic. Lopez (guns in school zones) and Morrison (gender violence) — non-economic; fails substantial-effects.
• Dormant CC discrimination. Facial, purpose, or effect — triggers near-strict scrutiny.
• Pike balancing. Non-discriminatory + incidental burden — upheld unless clearly excessive.
• Market-participant exception. Only as direct buyer/seller/employer; doesn't extend to post-sale "downstream" restrictions (South-Central Timber).
• P&I Clause. Only individuals; only fundamental rights; doesn't cover corporations.
• Federal statutes can authorize state action. Congress may consent to state discrimination against interstate commerce, neutralizing dormant CC.

Fast hypos

Hypo 1. State law bans importation of out-of-state garbage. Facially discriminatory — invalid under *Philadelphia v. New Jersey.*

Hypo 2. State requires milk retailers to price-certify out-of-state milk against in-state prices. Discriminatory in purpose — likely invalid.

Hypo 3. State acts as purchaser of school buses, preferring in-state manufacturers. Market participant — not barred by dormant CC.

Hypo 4. State limits commercial-truck length to 55 feet; neighbors allow 65 feet. Burden on interstate commerce under *Pike; may be invalid if local safety benefits not substantial.*

Hypo 5. State requires out-of-state lawyers to pass an in-state residency test to take the bar. Privileges & Immunities — fundamental right to earn a living; invalid absent substantial reason.

Case anchors

• United States v. Lopez, 514 U.S. 549 (1995) — guns in school zones beyond Commerce power.
• United States v. Morrison, 529 U.S. 598 (2000) — gender-motivated violence not economic.
• Wickard v. Filburn, 317 U.S. 111 (1942) — aggregation of farm wheat.
• Gonzales v. Raich, 545 U.S. 1 (2005) — homegrown medical marijuana.
• NFIB v. Sebelius, 567 U.S. 519 (2012) — individual mandate limits.
• Philadelphia v. New Jersey, 437 U.S. 617 (1978) — facial discrimination.
• Pike v. Bruce Church, 397 U.S. 137 (1970) — balancing test.
• Hughes v. Oklahoma, 441 U.S. 322 (1979) — natural-resource protectionism.
• South Dakota v. Wayfair, 585 U.S. 162 (2018) — overruled physical-presence rule for state sales tax.

See also

• Equal Protection
• Freedom of Speech
• Takings
• First Amendment — Speech

Sources

U.S. Const. art. I, § 8, cl. 3; art. IV, § 2; United States v. Lopez, 514 U.S. 549 (1995); United States v. Morrison, 529 U.S. 598 (2000); Wickard v. Filburn, 317 U.S. 111 (1942); Gonzales v. Raich, 545 U.S. 1 (2005); Philadelphia v. New Jersey, 437 U.S. 617 (1978); Pike v. Bruce Church, 397 U.S. 137 (1970); South Dakota v. Wayfair, 585 U.S. 162 (2018).