Ammex, Inc. v. Gordon Wenk, 936 F.3d 355

Background

Ammex operates a duty-free store in Wayne County, Michigan, selling duty-free gasoline to cross-border travelers; MDARD enforces Michigan’s Summer Fuel Law limiting summer RVP to 7.0 psi in certain counties.
Michigan enacted House Bill 5508 (Summer Fuel Law) after EPA designated several counties nonattainment for ozone; Michigan submitted the measure in its SIP and the EPA approved and incorporated it into the CFR.
Ammex previously complied with the 7.0 psi requirement in summers 2013–2017 but in 2018 could not source compliant fuel while meeting federal customs/duty-free sourcing requirements.
MDARD tested Ammex’s fuel in 2012, found noncompliance, issued stop-sale, and later settled with court-ordered compliance; in 2018 Ammex sought a declaratory judgment and a preliminary injunction to bar MDARD enforcement, claiming Supremacy Clause preemption and dormant Foreign Commerce Clause violation.
The district court denied the preliminary injunction; the Sixth Circuit affirmed, holding that MDARD’s enforcement is enforcement of federal law (because the SIP-approved standard is federal), so Ammex lacked likelihood of success on its constitutional claims.

Issues

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Michigan’s Summer Fuel Law (as enforced by MDARD) is federal law	Ammex: the state statute remains state law and Ammex seeks only to enjoin state enforcement; the parallel federal regulation does not transform state law into federal law	Wenk/MDARD: EPA approved Michigan’s RVP standard into the SIP and CFR; approval plus EPA enforcement authority makes the standard federal law	Court: SIP-incorporated RVP standard is federal law; MDARD’s enforcement is enforcement of federal law
Whether MDARD enforcement violates the dormant Foreign Commerce Clause	Ammex: law burdens foreign commerce (duty-free/export sales) and attempts to regulate goods not entering U.S. commerce	MDARD: statute targets in-state sales occurring in Michigan and Congress acquiesced via the CAA/SIP process; one-voice concerns are addressed	Court: no need to decide because enforcement is federal law; alternatively, SIP approval and Congressional scheme evince acquiescence so no dormant foreign commerce violation
Whether the Summer Fuel Law is preempted (Supremacy Clause)	Ammex: federal customs/duty-free regime conflicts with state RVP requirement or occupies the field for bonded/duty-free sales	MDARD: no conflict; simultaneous compliance is possible (Ammex had complied previously) and federal law does not occupy the field entirely	Court: because SIP is federal law, Supremacy challenge fails; even if viewed as state law, no field or conflict preemption shown
Whether Ammex was entitled to a preliminary injunction	Ammex: likely to succeed on merits and irreparable harm without injunction	MDARD: Ammex unlikely to succeed; public interest and enforcement scheme counsel denial	Court: Ammex not likely to succeed on merits; denied preliminary injunction and denial affirmed

Key Cases Cited

Sierra Club v. Korleski, 681 F.3d 342 (6th Cir.) (discussing that EPA-approved SIPs become part of federal law)
Her Majesty the Queen in Right of the Province of Ontario v. City of Detroit, 874 F.2d 332 (6th Cir. 1989) (stating approved SIP requirements become federal law)
Grp. Against Smog & Pollution, Inc. v. Shenango Inc., 810 F.3d 116 (3d Cir.) (approved SIPs bind as federal law)
California Dump Truck Owners Ass’n v. Nichols, 784 F.3d 500 (9th Cir.) (distinguishing unapproved state rules from SIP-approved federal requirements)
Indiana v. EPA, 796 F.3d 803 (7th Cir.) (approved state rules in SIP enforceable as federal law)
U.S. Magnesium, LLC v. EPA, 690 F.3d 1157 (10th Cir.) (approved SIPs enforceable as federal law)
Obama for Am. v. Husted, 697 F.3d 423 (6th Cir.) (preliminary-injunction standard and constitutional claims)
Japan Line, Ltd. v. County of Los Angeles, 441 U.S. 434 (U.S. 1979) (dormant foreign commerce clause and the one-voice doctrine)
Barclays Bank PLC v. Franchise Tax Bd. of Cal., 512 U.S. 298 (U.S. 1994) (Congressional acquiescence standard under dormant foreign commerce clause)
Healy v. Beer Institute, 491 U.S. 324 (U.S. 1989) (extraterritoriality doctrine under dormant commerce clause)
R.J. Reynolds Tobacco Co. v. Durham County, 479 U.S. 130 (U.S. 1986) (state taxation/regulation of goods under federal customs regime does not necessarily result in field preemption)