9.2 Preemption, the Dormant Commerce Clause & Congressional Authorization

9.2 Preemption, the Dormant Commerce Clause & Congressional Authorization

NCBE's outline pairs preemption with the dormant Commerce Clause because both ask when federal law or federal structure displaces a state regulation. Preemption depends on what Congress actually enacted; the dormant Commerce Clause applies even when Congress has said nothing. The Article IV Privileges and Immunities Clause, which also restricts discrimination against out-of-staters, is covered in Section 11.2.

---

1. The Supremacy Clause & Preemption (Art. VI, cl. 2)

Under Article VI, Clause 2 (the Supremacy Clause), the United States Constitution, federal statutes enacted pursuant to constitutional authority, and international treaties constitute the "supreme Law of the Land," binding upon judges in every state regardless of anything to the contrary in state laws or state constitutions. When a state law conflicts with valid federal law, the state law is preempted and rendered void.

The Presumption Against Preemption

In areas of historic or traditional state police power (e.g., public health, worker safety, highway management, common law tort remedies), courts operate under a strong presumption against preemption. The court will not find preemption unless that was the "clear and manifest purpose of Congress" (Medtronic, Inc. v. Lohr). When a statute contains an express preemption clause, however, the Court does not apply a presumption against preemption to that clause; it focuses on the clause's plain wording (Puerto Rico v. Franklin California Tax-Free Trust, 2016).

Categories of Federal Preemption

                      ┌─────────────────────────────────────────┐
                      │       CATEGORIES OF PREEMPTION          │
                      └────────────────────┬────────────────────┘
                                           │
         ┌─────────────────────────────────┴─────────────────────────────────┐
         │                                                                   │
         ▼                                                                   ▼
┌─────────────────┐                                                 ┌─────────────────┐
│     EXPRESS     │                                                 │     IMPLIED     │
│ - Explicit text │                                                 │   PREEMPTION    │
│   in federal    │                                                 └────────┬────────┘
│   statute       │                                                          │
└─────────────────┘                                ┌─────────────────────────┴─────────────────────────┐
                                                   │                                                   │
                                                   ▼                                                   ▼
                                        ┌─────────────────────┐                             ┌─────────────────────┐
                                        │   FIELD PREEMPTION  │                             │ CONFLICT PREEMPTION │
                                        │ - Pervasive federal │                             │ 1. Impossibility    │
                                        │   regulatory scheme │                             │ 2. Obstacle to      │
                                        │   occupies domain   │                             │    federal objective│
                                        └─────────────────────┘                             └─────────────────────┘

1. Express Preemption

Express preemption occurs when a federal statute contains an explicit preemption clause declaring that federal law supersedes state laws governing the subject matter (e.g., ERISA: "shall supersede any and all State laws insofar as they may now or hereafter relate to any employee benefit plan"). The judicial inquiry is strictly one of statutory interpretation: determining the exact boundaries and scope of the preemption clause.

2. Implied Preemption: Field Preemption

Field preemption occurs when congressional regulation in a particular area is so comprehensive and pervasive as to leave no room for supplementary state legislation, reflecting a clear intent by Congress to occupy the entire legislative field.

• Dominant Federal Interest: Field preemption is frequently found in areas where the federal interest is inherently dominant, such as immigration alien registration and enforcement (Arizona v. United States, 2012) and nuclear power safety regulation (Pacific Gas & Electric Co. v. State Energy Resources Conservation & Development Comm'n).
• State Supplementation Barred: When Congress occupies a field, even state laws that share the identical objective or impose parallel penalties are preempted.

3. Implied Preemption: Conflict Preemption

Conflict preemption arises even in the absence of field preemption whenever state and federal law clash. It takes two distinct forms:

• Impossibility Preemption: Compliance with both federal and state law simultaneously is a physical or legal impossibility (e.g., federal law mandates labeling substance X with warning label A, while state law makes placing label A on substance X a criminal misdemeanor).
• Obstacle Preemption: The state law stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress (Hines v. Davidowitz). If enforcement of the state statute frustrates, undermines, or interferes with the delicate balance struck by a federal regulatory program or foreign policy, the state statute is preempted.

---

2. The Dormant Commerce Clause (DCC)

The Constitutional Premise

Article I, Section 8, Clause 3 grants Congress affirmative authority to regulate interstate commerce. The Supreme Court has long recognized that this affirmative grant contains a negative, self-executing implication: even when Congress has not enacted legislation on a commercial matter (meaning the commerce power lies dormant), state and local governments are prohibited from enacting legislation that unduly burdens or discriminates against interstate commerce.

The foundational purpose of the Dormant Commerce Clause is to prevent state economic protectionism, tariff wars, and commercial Balkanization, ensuring that the United States functions as a single national common market.

The Two-Track Analytical Framework

To evaluate a state or local economic regulation under the Dormant Commerce Clause, courts apply a two-track inquiry based on whether the law is discriminatory or facially neutral:

                    ┌──────────────────────────────────────────────┐
                    │   DOES THE STATE OR LOCAL REGULATION         │
                    │   DISCRIMINATE AGAINST INTERSTATE COMMERCE?  │
                    └──────────────────────┬───────────────────────┘
                                           │
                         YES               │              NO
                         ▼                 │               ▼
               ┌───────────────────┐       │     ┌───────────────────┐
               │  STRICT SCRUTINY  │       │     │   PIKE BALANCING  │
               │ Virtually per se  │       │     │        TEST       │
               │      invalid      │       │     │ Upheld unless     │
               │ State must prove  │       │     │ burden clearly    │
               │ compelling local  │       │     │ excessive to      │
               │ need & NO non-    │       │     │ putative local    │
               │ discriminatory    │       │     │ benefits          │
               │ alternatives      │       │     └───────────────────┘
               └───────────────────┘       │

Track 1: Discriminatory Regulations (Strict Scrutiny / Virtually Per Se Invalid)

A state or local law discriminates against interstate commerce if it accords different treatment to in-state and out-of-state economic interests in a manner that benefits the former and burdens the latter. Discrimination manifests in three forms:

1. Facial Discrimination: The statutory text explicitly distinguishes between in-state and out-of-state commerce (e.g., City of Philadelphia v. New Jersey, 1978, striking down a state law banning the importation of out-of-state solid waste; Dean Milk Co. v. City of Madison, 1951, invalidating an ordinance banning milk sales unless pasteurized within five miles of the city square);
2. Discriminatory Purpose / Intent: A statute enacted with the legislative objective of shielding local industries, jobs, or businesses from out-of-state competition; or
3. Discriminatory Practical Effect: A facially neutral statute that operates in reality to disadvantage out-of-state competitors while favoring in-state enterprises (Hunt v. Washington State Apple Advertising Commission, 1977, striking down a North Carolina statute prohibiting display of state apple grading systems on shipping crates, which stripped Washington growers of their competitive advantage while leaving local growers unaffected).

The Standard of Review: Discriminatory regulations are subject to strict scrutiny and are virtually per se unconstitutional. The state carries the heavy burden of proving that:

• The statute serves a legitimate, non-protectionist local interest (e.g., ecological protection, genuine health or safety); AND
• That interest cannot be adequately served by reasonable, non-discriminatory alternative means.

A Rare Discriminatory Law That Survived (Maine v. Taylor, 1986): The Supreme Court upheld Maine's ban on importing out-of-state live baitfish because the state proved that out-of-state baitfish carried specific ecological parasites and non-native predator species that could destroy native fish populations, and no scientific testing method existed to inspect baitfish shipments at the border. There were no non-discriminatory alternatives.

Track 2: Non-Discriminatory Regulations (Pike Balancing Test)

Where a state or local statute regulates even-handedly to effectuate a legitimate local public interest and imposes only incidental burdens on interstate commerce, it is evaluated under the balancing test articulated in Pike v. Bruce Church, Inc. (1970):

• The Rule: The regulation will be upheld UNLESS the burden imposed on interstate commerce is clearly excessive in relation to the putative local benefits.
• Balancing Factors: Courts examine the nature and extent of the local benefit (e.g., highway safety, environmental protection, fraud prevention), the degree of disruption to the interstate transport of goods, and whether the local objective could be achieved just as effectively with a lesser impact on interstate commerce.
• Case Illustrations:
  • Bibb v. Navajo Freight Lines, Inc. (1959): Illinois statute requiring curved rear mudguards on all trucks, while 45 other states permitted straight mudguards and neighboring Arkansas required straight ones, created massive interstate trucking delays with negligible safety benefits; struck down under Pike.
  • Kassel v. Consolidated Freightways Corp. (1981): Iowa statute prohibiting 65-foot double-trailer trucks on state highways, while surrounding states permitted them, imposed massive rerouting costs on interstate carriers with unproven safety benefits; struck down under Pike.

State Taxation of Interstate Commerce

A state tax on interstate commerce does not violate the Dormant Commerce Clause if it satisfies the four-part test established in Complete Auto Transit, Inc. v. Brady (1977):

1. Substantial Nexus: The taxed commercial activity has a substantial nexus with the taxing state (established by physical presence or significant economic activity within the state, South Dakota v. Wayfair, Inc., 2018);
2. Fairly Apportioned: The tax is fairly apportioned so that interstate businesses are not subjected to multiple taxation by different states on the same economic income;
3. Non-Discriminatory: The tax does not discriminate against interstate commerce (e.g., imposing higher rates on out-of-state sales or providing tax exemptions exclusively for in-state products, Bacchus Imports, Ltd. v. Dias); and
4. Fairly Related to Services: The tax is fairly related to the services, protections, and benefits provided to the taxpayer by the taxing state.

---

3. Exceptions to the Dormant Commerce Clause

A state regulation that would otherwise violate the Dormant Commerce Clause will be sustained if it falls into one of three established exceptions:

1. Congressional Authorization / Approval

Congress possesses plenary, paramount constitutional authority over interstate commerce under Article I, Section 8. If Congress passes a federal statute expressly authorizing states to regulate an aspect of interstate commerce or discriminate against out-of-state commerce, state legislation enacted pursuant to that authorization is completely immune from Dormant Commerce Clause attack (Western & Southern Life Insurance Co. v. State Board of Equalization, 1981; McCarran-Ferguson Act authorizing state insurance regulation).

2. The Market Participant Doctrine

When a state or municipal government enters the commercial marketplace as an economic buyer, seller, producer, or employer (a market participant), rather than acting in its sovereign regulatory capacity (a market regulator), the Dormant Commerce Clause does not apply.

• Under this doctrine, a state may favor its own residents or local businesses just as any private commercial business entity would:
  • Hughes v. Alexandria Scrap Corp. (1976): Maryland could pay cash bounties to scrap processors for recycling abandoned vehicle hulks and require more stringent documentation from out-of-state processors;
  • Reeves, Inc. v. Stake (1980): South Dakota could own and operate a commercial cement plant and restrict cement sales exclusively to state residents during a regional cement shortage;
  • White v. Massachusetts Council of Construction Employers, Inc. (1983): The City of Boston could mandate that at least 50% of the workforce on all city-funded public construction projects be Boston residents.

The Downstream Market Limitation

The market participant exception allows a state to favor local citizens only within the immediate commercial transaction in which the state participates. A state cannot use its market participant status to regulate downstream commercial transactions outside that market (South-Central Timber Development, Inc. v. Wunnicke, 1984). In Wunnicke, Alaska sold state-owned timber at market rates, but imposed a contractual condition requiring that the buyer process the timber at an in-state Alaskan sawmill prior to export. The Supreme Court struck down the condition, holding that once the timber was sold, Alaska was regulating the downstream timber processing market as a sovereign, not participating as a timber seller.

3. Traditional Public Entity Monopolies

In United Haulers Ass'n, Inc. v. Oneida-Herkimer Solid Waste Management Authority (2007), the Court held that a local flow-control ordinance requiring all municipal solid waste to be delivered to a publicly owned, publicly operated local waste processing facility did not violate the DCC. Laws favoring local public government entities performing traditional governmental functions treat all private companies (in-state and out-of-state) identically, unlike laws favoring local private businesses.

---

Applying Preemption and Dormant Commerce Clause Rules

Preemption in Practice

• Immigration: In Arizona v. United States (2012), the Court held that federal law occupies the field of alien registration, so a state crime for failing to carry federal registration papers was preempted, and a state crime for unauthorized noncitizens seeking work was preempted as an obstacle to Congress's decision to penalize employers rather than employees. But states may prosecute people under general identity-theft laws for using false information on state and federal tax forms (Kansas v. Garcia, 2020).
• Drug labeling: A state failure-to-warn claim against a brand-name drug maker was not preempted because the maker could have strengthened its label under federal rules (Wyeth v. Levine, 2009), but similar claims against generic manufacturers, which must use the same label as the brand-name drug, were preempted because compliance with both was impossible (PLIVA, Inc. v. Mensing, 2011).
• Federal choices: When federal law deliberately gives regulated parties a menu of options, a state law requiring one option can be preempted as an obstacle (Geier v. American Honda Motor Co., 2000).
• Savings clauses and floors: If Congress sets minimum standards and preserves more protective state laws, stricter state rules are not preempted.
• Regulations count: Valid federal agency regulations preempt conflicting state law just as statutes do (Fidelity Federal Savings & Loan Ass'n v. de la Cuesta, 1982).

Recent Dormant Commerce Clause Rules

• No extraterritoriality per se rule: In National Pork Producers Council v. Ross (2023), the Court rejected the argument that a state law is automatically invalid because it has practical effects on commerce outside the state. California's ban on in-state sales of pork from pigs confined in small spaces did not discriminate against out-of-state producers, and increased compliance costs for out-of-state farms did not state a successful claim. Antidiscrimination remains the core of the doctrine.
• Burdens on out-of-state firms are not automatically discrimination: A law that burdens some interstate companies but does not favor in-state companies over out-of-state competitors is not discriminatory (Exxon Corp. v. Governor of Maryland, 1978).
• Alcohol: The Twenty-First Amendment gives states broad power over alcohol, but it does not permit protectionist discrimination, such as allowing in-state but not out-of-state wineries to ship directly to consumers (Granholm v. Heald, 2005) or imposing a two-year residency requirement on liquor store owners (Tennessee Wine & Spirits Retailers Ass'n v. Thomas, 2019).
• Public functions: A state may exempt interest on its own bonds from state income tax while taxing out-of-state bonds, because issuing debt is a traditional government function (Department of Revenue of Kentucky v. Davis, 2008).
• Congressional consent must be clear: Congress must make its intent to authorize otherwise-invalid state burdens on commerce unmistakably clear (South-Central Timber Development, Inc. v. Wunnicke). Congressional consent does not authorize violations of other provisions, such as the Equal Protection Clause.