Amicus Curiae Brief — Monsanto Company, Petitioner v. John L. Durnell
Supreme Court briefMar 2, 2026
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No. 24-1068
In the
Supreme Court of the United States
_______________
MONSANTO COMPANY,
Petitioner,
v.
JOHN L. DURNELL,
Respondent.
________________
On Writ of Certiorari to the
Missouri Court of Appeals
________________
BRIEF OF AMERICAN FREE ENTERPRISE
CHAMBER OF COMMERCE AS AMICUS
CURIAE IN SUPPORT OF PETITIONER
_______________
Michael Buschbacher
James R. Conde
Counsel of Record
Walker Fortenberry
BOYDEN GRAY PLLC
800 Connecticut Ave. NW
Suite 900
Washington, DC 20006
(202) 955-0620
jconde@boydengray.com
i
TABLE OF CONTENTS
TABLE OF AUTHORITIES....................................... ii
INTEREST OF AMICUS CURIAE ........................... 1
INTRODUCTION AND SUMMARY OF THE
ARGUMENT .............................................................. 2
BACKGROUND ......................................................... 6
I.
THE STATUTE .................................................... 6
II.
THE DECISION BELOW ....................................... 7
ARGUMENT .............................................................. 9
I.
COURTS ARE CONFUSED ABOUT THE
PRESUMPTION AGAINST PREEMPTION ............... 9
A. This Court’s Decisions Are Confusing ............ 9
B. Lower Courts Are Confused .......................... 15
II.
THE PRESUMPTION AGAINST PREEMPTION
DEFIES THE CONSTITUTION, TEXTUALISM,
AND HISTORY .................................................. 18
III. MISSOURI RULE’S CONTRADICTS FIFRA ......... 22
CONCLUSION ......................................................... 25
ii
TABLE OF AUTHORITIES
Page(s)
Cases
Air Evac EMS, Inc. v. Cheatham,
910 F.3d 751 (4th Cir. 2018) .......................... 15, 16
Altria Grp., Inc. v. Good,
555 U.S. 70 (2008) .................................... 11, 18, 20
Atay v. County of Maui,
842 F.3d 688 (9th Cir. 2016) .......................... 15, 17
Bates v. Dow Agrosciences LLC,
544 U.S. 431 (2005) ................................................ 6
Bedoya v. Am. Eagle Express Inc.,
914 F.3d 812 (3d Cir. 2019) ................................. 16
Biden v. Nebraska,
600 U.S. 477 (2023) ........................................ 20, 21
Bruesewitz v. Wyeth LLC,
562 U.S. 223 (2011) .............................................. 11
Cal. Rest. Ass’n v. City of Berkeley,
89 F.4th 1094 (9th Cir. 2024) ............. 3, 12, 15, 16
Carson v. Monsanto Co.,
72 F.4th 1261 (11th Cir. 2023) ............................ 15
Carson v. Monsanto Co.,
92 F.4th 980 (11th Cir. 2024) .............................. 17
iii
Chamber of Com. of U.S. of Am. v.
Whiting, 563 U.S. 582 (2011)................................. 9
Cipollone v. Liggett Group,
505 U.S. 504 (1992) ........................................ 10, 21
Cohens v. Virginia,
19 U.S. (6 Wheat.) 264 (1821) .............................. 21
Connell v. Lima Corp.,
988 F.3d 1089 (9th Cir. 2021) .............................. 17
Council for Responsible Nutrition v.
James, 159 F.4th 155 (2d Cir. 2025) ................... 15
CTS Corp. v. Waldburger,
573 U.S. 1 (2014) .................................................. 11
Cuomo v. The Clearing House Ass’n,
LLC, 557 U.S. 519 (2009)..................................... 12
Dan’s City Used Cars, Inc. v. Pelkey,
569 U.S. 251 (2013) .............................................. 11
De Buono v. NYSA-ILA Med. & Clinical
Servs. Fund, 520 U.S. 806 (1997) ........................ 11
Dialysis Newco, Inc. v. Cmty. Health
Sys. Grp. Health Plan,
938 F.3d 246 (5th Cir. 2019) ................................ 15
EagleMed LLC v. Cox,
868 F.3d 893 (10th Cir. 2017) .............................. 15
iv
English v. Gen. Elec. Co.,
496 U.S. 72 (1990) .................................................. 9
Fenner v. Gen. Motors, LLC,
113 F.4th 585 (6th Cir. 2024) .............................. 16
Garcia v. San Antonio Metro. Transit
Auth., 469 U.S. 528 (1985) ................................... 14
Geier v. Am. Honda Motor Co.,
529 U.S. 861 (2000) .............................................. 13
Gibbons v. Ogden,
22 U.S. (9 Wheat.) 1 (1824) .................................. 20
Glacier Nw., Inc. v. Int’l Bhd. of
Teamsters Loc. Union No. 174,
598 U.S. 771 (2023) .............................................. 22
Happel v. Guilford Cnty. Bd. of Educ.,
913 S.E.2d 174 (N.C. 2025) .................................. 16
Hardeman v. Monsanto Co.,
997 F.3d 941 (9th Cir. 2021) ................................ 17
Int’l Bhd. of Teamsters, Loc. 2785 v.
Fed. Motor Carrier Safety Admin.,
986 F.3d 841 (9th Cir. 2021) ................................ 17
Kaipust v. Echo Glob. Logistics, Inc.,
271 N.E.3d 1066 (Ill. App. Ct. 2025) ................... 16
Kansas v. Garcia,
589 U.S. 191 (2020) .......................... 2, 9, 14, 20, 24
v
Klotz v. Celentano Stadtmauer &
Walentowicz LLP,
991 F.3d 458 (3d Cir. 2021) ................................. 18
Lofton v. McNeil Consumer & Specialty
Pharms.,
672 F.3d 372 (5th Cir. 2012) ................................ 16
Loper Bright Enters. v. Raimondo,
603 U.S. 369 (2024) .................................. 14, 15, 22
Lorillard Tobacco Co. v. Reilly,
533 U.S. 525 (2001) .............................................. 11
Lupian v. Joseph Cory Holdings, LLC,
905 F.3d 127 (3d Cir. 2018) ................................. 18
Marrache v. Bacardi U.S.A., Inc.,
17 F.4th 1084 (11th Cir. 2021) ............................ 16
Mayor of New York v. Miln,
36 U.S. (11 Pet.) 102 (1837) ................................. 20
Medicaid & Medicare Advantage Prods.
Ass’n of P.R., Inc. v. Emanuelli
Hernández, 58 F.4th 5 (1st Cir. 2023) ................. 15
Medtronic, Inc. v. Lohr,
518 U.S. 470 (1996) .................................... 2, 11, 21
Merck Sharp & Dohme Corp. v.
Albrecht,
587 U.S. 299 (2019) ................................................ 4
vi
Mintz v. Baldwin,
289 U.S. 346 (1933) .............................................. 21
Mont. Med. Ass’n v. Knudsen,
119 F.4th 618 (9th Cir. 2024) .............................. 16
Mut. Pharm. Co. v. Bartlett,
570 U.S. 472 (2013) .................................... 9, 11, 13
Nat’l Meat Ass’n v. Harris,
565 U.S. 452 (2012) .............................................. 11
Nat’l R.R. Passenger Corp. v. Su,
41 F.4th 1147 (9th Cir. 2022) .............................. 17
Osborn v. Bank of the United States,
22 U.S. (9 Wheat.) 738 (1824) .............................. 25
PLIVA, Inc. v. Mensing,
564 U.S. 604 (2011) .............................. 2, 13, 16, 19
Puerto Rico v. Franklin Cal. Tax-Free
Tr., 579 U.S. 115 (2016) ................................. 12, 20
R.J. Reynolds Tobacco Co. v. County of
Los Angeles,
29 F.4th 542 (9th Cir. 2022) ................................ 17
Riegel v. Medtronic,
552 U.S. 312 (2008) .............................................. 11
Rowe v. N.H. Motor Transp. Ass’n,
552 U.S. 364 (2008) .............................................. 11
vii
Schaffner v. Monsanto Corp.,
113 F.4th 364 (3d Cir. 2024) ............................ 7, 17
Seven County Infrastructure Coal. v.
Eagle County, 605 U.S. 168 (2025) ........................ 3
Shuker v. Smith & Nephew, PLC,
885 F.3d 760 (3d Cir. 2018) ..................... 15, 16, 18
Va. Uranium, Inc. v. Warren,
587 U.S. 761 (2019) .................................... 9, 10, 14
Watson v. Air Methods Corp.,
870 F.3d 812 (8th Cir. 2017) ................................ 15
Wyeth v. Levine,
555 U.S. 555 (2009) ........................................ 13, 21
Constitutional Provisions
U.S. Const. art. VI, cl. 2 ............................................ 19
Statutes
7 U.S.C. § 136(x) .................................................... 6, 23
7 U.S.C. § 136(bb) ........................................................ 6
7 U.S.C. § 136(q)(1)(G) .......................................... 6, 23
7 U.S.C. § 136a(a) ........................................................ 6
7 U.S.C. § 136a(c) ........................................................ 6
viii
7 U.S.C. § 136a(c)(5)(B) ............................................... 6
7 U.S.C. § 136a(c)(5)(C) ............................................... 6
7 U.S.C. § 136a(c)(5)(D) ............................................... 6
7 U.S.C. § 136j(a)(1)(B) ............................................... 6
7 U.S.C. § 136v(a) ........................................................ 7
7 U.S.C. § 136v(b) .............................................. 5, 7, 23
7 U.S.C. § 136w(a)(1) ................................................... 7
7 U.S.C. § 136w(a)(2) ................................................... 7
15 U.S.C. § 1334(b) .................................................... 10
Other Authorities
40 C.F.R. § 152.44(a) ................................................... 7
Amy Coney Barrett, Substantive
Canons and Faithful Agency,
90 B.U. L. Rev. 109 (2010) ........................... 2, 3, 20
Antonin Scalia & Bryan A. Garner,
Reading Law: The Interpretation of
Legal Texts (2012) .......................................... 10, 23
Caleb Nelson, Preemption,
86 Va. L. Rev. 225, 232 (2000) .... 2, 3, 9, 18, 19, 23
ix
Michael S. Greve, The Upside-Down
Constitution (2012) .......................................... 4, 21
Omri Ben-Shahar & Carl E. Schneider,
More Than You Wanted to Know:
The Failure of Mandated Disclosure
(2014) ...................................................................... 7
Robert R. Gasaway & Ashley C.
Parrish, The Problem of Federal
Preemption: Toward a Formal
Solution, in Federal Preemption:
States’ Powers, National Interests
219 (Richard A. Epstein & Michael
S. Greve eds., 2007).............................................. 23
Stephen Gardbaum, New Deal
Constitutionalism and the
Unshackling of the States,
64 U. Chi. L. Rev. 483 (1997)........................... 3, 21
Viet D. Dinh, Federal Displacement of
State Law: The Nineteenth Century
View, in Federal Preemption: States’
Powers, National Interests 27
(Richard A. Epstein & Michael S.
Greve eds., 2007) .................................................. 20
1
INTEREST OF AMICUS CURIAE1
Formed in 2022, the American Free Enterprise
Chamber of Commerce (“AmFree”) is an entity organized consistent with section 501(c)(6) of the Internal
Revenue Code that represents hard-working entrepreneurs and businesses across all sectors of the U.S.
economy. AmFree’s members are vitally interested in
protecting the continued viability of our commercial
republic, including by protecting its members from
patchwork legal regimes. AmFree launched the Center for Legal Action to represent these interests in
court.
1
No counsel for any party has authored this brief in whole or in
part, and no entity or person, aside from Amicus’s counsel, made
any monetary contribution intended to fund the preparation or
submission of this brief.
2
INTRODUCTION AND
SUMMARY OF THE ARGUMENT
“Modern preemption jurisprudence is a muddle.”
See Caleb Nelson, Preemption, 86 Va. L. Rev. 225, 232
(2000). Although written more than 25 years ago, Professor Caleb Nelson’s words still ring true.
1. Much of that confusion can be traced to the presumption against preemption, which instructs courts
“[i]n all pre-emption cases” to “start with the assumption that the historic police powers of the State [are]
not to be superseded by the Federal Act unless that
was the clear and manifest purpose of Congress.”
Medtronic, Inc. v. Lohr, 518 U.S. 470, 485 (1996)
(cleaned up).
As five Justices have explained, the presumption
against preemption conflicts with the Supremacy
Clause. The Clause includes a non obstante provision
instructing “that courts should not strain to find ways
to reconcile federal law with seemingly conflicting
state law.” PLIVA, Inc. v. Mensing, 564 U.S. 604, 622
(2011) (plurality op.) (Thomas, J., joined by Roberts,
C.J., Scalia & Alito, JJ.); Kansas v. Garcia, 589 U.S.
191, 213–14 (2020) (Thomas, J., concurring, joined by
Gorsuch, J.). This judge-made normative canon also
has no footing in early methods of interpreting the Supremacy Clause. See Amy Coney Barrett, Substantive
Canons and Faithful Agency, 90 B.U. L. Rev. 109, 153
n.211 (2010) (“Early cases confronting preemption analyzed the issue without discussing any special interpretive rule.”). Importantly, the modern version of the
canon protecting state regulatory fiefdoms originated
3
during the New Deal and rests upon policy concerns
with preempting too much state regulation as federal
law expanded at the same time. See Stephen Gardbaum, New Deal Constitutionalism and the Unshackling of the States, 64 U. Chi. L. Rev. 483, 536–40
(1997). These policy concerns may not override the
Constitution. When there is a conflict between federal
and state law, judges have no authority to narrowly
construe federal law to avoid the conflict. Doing so is
not “faithful agency.” Barrett, supra, at 181.
But despite its inconsistency with constitutional
text and textualism, the presumption against preemption lives on in federal and state courts, and, as here,
sometimes rears its head even when Congress has
spoken by expressly preempting state law.
Pet. App. 4. The result is “a deeply troubled area of
law” and “conflicting lines of cases.” Cal. Rest. Ass’n v.
City of Berkeley, 89 F.4th 1094, 1107 (9th Cir. 2024)
(O’Scannlain, J., concurring).
“In deciding cases involving the American economy, courts should strive, where possible, for clarity
and predictability.” Seven County Infrastructure Coal.
v. Eagle County, 605 U.S. 168, 192 (2025). The Court
should clarify this “vitally important” area, Nelson,
supra, at 225–26, by holding that the Supremacy
Clause does not countenance a judge-made presumption against preemption.
2. Rejecting a judicial thumb on the scale does not
resolve this case; it merely sets the stage. The Court
must still decide whether the Federal Insecticide,
4
Fungicide, and Rodenticide Act (“FIFRA”) conflicts
with Missouri’s rule of decision here.
Most would agree that federal law conflicts with
state law at least when “the two are in logical contradiction.” Merck Sharp & Dohme Corp. v. Albrecht, 587
U.S. 299, 319 (2019) (Thomas, J., concurring). “It is
not easy to say, however, what constitutes a contradiction or conflict between federal and state law.” Michael S. Greve, The Upside-Down Constitution 108
(2012). “If federal law tells a private citizen to do A
and state law tells him to do B instead, the conflict is
manifest. What though, if a state law says ‘more than
A’”? Id.
Sometimes, “more than A” will contradict federal
law, if not expressly, then impliedly. When Congress
entrusts a federal agency with a “golden mean”—balancing risks against benefits to get regulation “just
right”—the best reading is that Congress entrusted
the agency with authority to set a national ceiling, not
just a floor that states can trample upon. State laws
that go beyond federal law setting a more stringent
ceiling are logically repugnant to such a Goldilocks
scheme, except where the statute expressly provides
otherwise.
FIFRA creates such a Goldilocks health and
safety scheme for labeling pesticides. FIFRA requires
the U.S. Environmental Protection Agency (“EPA”) to
strike a reasonable balance between the health,
safety, and environmental risks of a pesticide label
and its societal benefits and the countervailing risk of
excessive warnings. FIFRA’s Uniformity Clause con-
5
firms that reading, prohibiting additional or even different state labeling requirements. See 7 U.S.C.
§ 136v(b). When Congress orders that pesticide labels
be “just right,” states cannot unilaterally say they are
wrong.
3. That’s what happened here. The state-law rule
of decision that the jury applied contradicts FIFRA by
going beyond EPA’s approved label for glyphosate
products and requiring Monsanto to add an unwarranted cancer warning. The Missouri Court of Appeals
purported to avoid the conflict by applying the presumption against preemption and then framing federal law at a high level of generality. Accepting that
framing tactic would enable the easy evasion of federal supremacy. Neither EPA when registering products nor state juries deal in vague generalities, and
neither should this Court’s vertical conflicts jurisprudence.
The Court should reverse, unequivocally abandon
the presumption against preemption, and enforce
Congress’s stated goal of national uniformity in labeling.
6
BACKGROUND
I.
THE STATUTE
FIFRA is a “comprehensive regulatory statute”
that governs the “use, as well as the sale and labeling,
of pesticides.” Bates v. Dow Agrosciences LLC, 544
U.S. 431, 437 (2005) (cleaned up). Under FIFRA, no
person may distribute or sell a pesticide unless it has
been registered by EPA. 7 U.S.C. § 136a(a). Registering a product requires complying with several procedural hurdles and submitting a wealth of health and
safety information to EPA. Id. § 136a(c).
EPA must register a pesticide if the label complies with FIFRA and the pesticide “will not generally
cause unreasonable adverse effects on the environment.” Id. § 136a(c)(5)(B), (C), (D). FIFRA defines that
phrase to include “any unreasonable risk to man or
the environment, taking into account the economic,
social, and environmental costs and benefits of the use
of any pesticide.” Id. § 136(bb). EPA must review the
label to ensure it is “adequate to protect health and
the environment,” see id. § 136(q)(1)(G), which includes protecting the public against “unreasonable”
risks to public health. Id. § 136(x). In short, EPA decides whether the pesticide and its label are the right
amount of “safe.”
Once EPA registers a pesticide, the pesticide’s labeling cannot contain “claims” that substantially differ from claims made to secure registration. Id.
§ 136j(a)(1)(B). By regulation, EPA requires registrants to seek approval of amendments to the label.
7
See 40 C.F.R. § 152.44(a); see also 7 U.S.C.
§ 136w(a)(1), (2) (“The Administrator is authorized …
to prescribe regulations to carry out the provisions of
this subchapter.”).
FIFRA expressly permits States to “regulate the
sale or use of any federally registered pesticide or device in the State.” 7 U.S.C. § 136v(a). But the statute
mandates nationwide uniformity in labeling:
(b) Uniformity— Such State shall not impose or continue in effect any requirements
for labeling or packaging in addition to or
different from those required under this
subchapter.
Id. § 136v(b).
II.
THE DECISION BELOW
Petitioner Monsanto Company sells registered
glyphosate-based pesticides under the brand name
“Roundup.” See Schaffner v. Monsanto Corp., 113
F.4th 364, 373 (3d Cir. 2024). As Monsanto explains,
EPA has repeatedly concluded that glyphosate-based
pesticides do not cause cancer and has refused to include a cancer warning in Roundup labeling requirements, deeming it unnecessary to protect public
health. Pet. Br. 10–18.
This makes sense. “More information is not better if it is wrong, or misleadingly incomplete, or irrelevant, or likely lead people to over- or under-emphasize elements of a decision.” Omri Ben-Shahar & Carl
E. Schneider, More Than You Wanted to Know: The
Failure of Mandated Disclosure 175 (2014).
8
Monsanto has nevertheless faced “over one hundred thousand lawsuits” alleging that Roundup
causes cancer. Pet. Br. 51–52. Some of these lawsuits
allege that Monsanto’s EPA-approved Roundup label
failed to warn the plaintiff of the risk of cancer.
This is such a case. In this case, a Missouri jury
awarded plaintiff John Durnell $1.25 million based
upon Monsanto’s failure to warn him about the alleged risk of cancer associated with using Roundup,
and the Missouri Court of Appeals affirmed the verdict. Pet. App. 2–12.
In rejecting Monsanto’s federal preemption argument, the Missouri Court of Appeals started by applying the presumption against preemption. Id. at 4.
Stating the purpose of FIFRA and Missouri law at a
high level of generality, the court then concluded that
Missouri’s rule didn’t impose any different or additional requirements because the general objectives of
FIFRA and Missouri law “are the same: both require
a pesticide manufacturer to adequately warn users of
the potential dangers of using its product.” Id. at 7.
The Missouri Court of Appeals also rejected Monsanto’s argument for implied preemption because the
precedents cited by Monsanto “all involve pharmaceutical products” and the court “decline[d] to extend
their holdings to pesticide products regulated under
FIFRA.” Id. at 11.
9
ARGUMENT
I.
COURTS ARE CONFUSED ABOUT
PRESUMPTION AGAINST PREEMPTION
THE
This Court has been less than clear about when
to invoke the presumption against preemption in both
express and implied preemption cases, spawning confusion in the lower courts. The result is an unworkable patchwork of conflicting approaches that cries for
the national uniform answer that only this Court can
provide.
A. This Court’s Decisions Are Confusing
“This Court has sometimes used different labels
to describe the different ways in which federal statutes may displace state laws—speaking, for example,
of express, field, and conflict preemption.” Va. Uranium, Inc. v. Warren, 587 U.S. 761, 767 (2019). Express preemption “occurs when a federal statute includes a preemption clause explicitly withdrawing
specified powers from the states.” Nelson, supra, at
226; see, e.g., Chamber of Com. of U.S. of Am. v. Whiting, 563 U.S. 582, 594–95 (2011). Field preemption occurs when “Congress legislated so comprehensively in
a particular field that it left no room for supplementary state legislation,” Kansas, 589 U.S. at 208
(cleaned up), and conflict or implied preemption occurs when a federal law “actually conflicts” with the
state law, English v. Gen. Elec. Co., 496 U.S. 72, 79
(1990). Implied preemption forbids, at a minimum,
“state laws that require a private party to violate federal law.” Mut. Pharm. Co. v. Bartlett, 570 U.S. 472,
10
475 (2013). “But these categories are not rigidly distinct.” Va. Uranium, 587 U.S. at 767 (cleaned up).
1. Express Preemption
In Cipollone v. Liggett Group, 505 U.S. 504 (1992)
(plurality op.), this Court considered whether an express preemption provision of the Federal Cigarette
Labeling and Advertising Act, 15 U.S.C. § 1334(b),
preempts common-law claims alleging that cigarette
makers misled the public about the health effects of
cigarettes. A plurality opinion written by Justice Stevens relied upon a “presumption against the pre-emption of state police power regulations” to give the
preemption provision a “narrow reading,” and ultimately held that some of the common-law claims
(breach of warranty, fraud, and conspiracy) were not
preempted by the federal statute. Cipollone, 505 U.S.
at 518, 524–31.
Justices Scalia and Thomas dissented in part,
criticizing the plurality’s application of the presumption to an expressly preemptive provision as “novel”
and contrary to “ordinary principles of statutory construction.” Id. at 547–48 (Scalia, J., concurring in the
judgment and dissenting in part, joined by Thomas,
J.). As Justice Scalia explained, “[t]he proper rule of
construction for express pre-emption provisions is, it
seems to me, the one that is customary for statutory
provisions in general: Their language should be given
its ordinary meaning.” Id. at 548; see also Antonin
Scalia & Bryan A. Garner, Reading Law: The Interpretation of Legal Texts 293 (2012) (“[T]he preemption
11
canon ought not to be applied to the text of an explicit
preemption provision.”).
Since Cipollone, this Court has sporadically invoked the presumption against preemption to construe preemption provisions.2 Other times, the Court
has mentioned the presumption without placing much
analytical weight on it.3 In some cases, the Court has
not mentioned the presumption.4 The Court has inconsistently applied the presumption even to the same
statute.5
2
See, e.g., Lohr, 518 U.S. at 500–01; De Buono v. NYSA-ILA Med.
& Clinical Servs. Fund, 520 U.S. 806, 814 (1997); Altria Grp.,
Inc. v. Good, 555 U.S. 70, 77 (2008); CTS Corp. v. Waldburger,
573 U.S. 1, 18–19 (2014).
3
Compare Lorillard Tobacco Co. v. Reilly, 533 U.S. 525, 541–42
(2001) (plurality op.), with id. at 592 (Stevens, J., concurring in
part, concurring in the judgment in part, and dissenting in part)
(“If Congress’ intent to pre-empt a particular category of regulation is ambiguous, such regulations are not pre-empted.”).
4
See, e.g., Rowe v. N.H. Motor Transp. Ass’n, 552 U.S. 364 (2008);
Bruesewitz v. Wyeth LLC, 562 U.S. 223 (2011); Nat’l Meat Ass’n
v. Harris, 565 U.S. 452 (2012); Dan’s City Used Cars, Inc. v.
Pelkey, 569 U.S. 251 (2013); Bartlett, 570 U.S. at 497–98 & n.1
(Sotomayor, J., dissenting) (noting that the presumption was
“conspicuously absent from the majority opinion”).
5
Compare Lohr, 518 U.S. at 500–01 (applying presumption
against preemption in holding that the manufacturing and labeling requirements of the Medical Device Amendments of 1976 did
not preempt state common-law claims), with Riegel v. Medtronic,
552 U.S. 312 (2008) (interpreting the scope of the same preemption provision without applying the presumption).
12
A decade ago, this Court stated that it would “not
invoke any presumption against pre-emption” “because the statute contains an express pre-emption
clause.” Puerto Rico v. Franklin Cal. Tax-Free Tr., 579
U.S. 115, 125 (2016) (cleaned up). Instead, the Court
“focus[ed] on the plain wording of the clause,” which
is “where the inquiry should end, for the statute’s language is plain.” Id. (cleaned up); see also Cuomo v. The
Clearing House Ass’n, LLC, 557 U.S. 519, 554 (2009)
(“There should be no presumption against pre-emption because Congress has expressly pre-empted state
law in this case.”).
Franklin should have been the end of the presumption in express preemption cases. But as Judge
O’Scannlain has explained, Franklin “left much room
for confusion”:
The Franklin Court did not acknowledge—
and, most importantly, did not expressly
overturn—the decades of decisions applying
the presumption against preemption to express-preemption provisions. And the
Franklin Court did not resolve—nor even
discuss—the scope of the rule it was applying. Was the Franklin Court simply electing
to “not invoke” the presumption in a case
easily answered by the “plain” statutory
text?
Cal. Rest. Ass’n, 89 F.4th at 1110 (O’Scannlain, J., concurring).
13
2. Implied Preemption
This Court has also inconsistently applied the
presumption against preemption in conflict or implied
preemption cases.
In Wyeth v. Levine, this Court relied upon the presumption against preemption in holding that the Federal Food, Drug, and Cosmetic Act did not impliedly
preempt failure-to-warn claims against a brand-name
drugmaker. 555 U.S. 555, 565 & n.3 (2009). But, Justice Alito argued in his dissent, the Court had earlier
“rejected the argument … that the ‘presumption
against preemption’” was “relevant to the conflict preemption analysis,” and called its relevance “an open
question.” Wyeth, 555 U.S. at 623–24 & n.14 (Alito, J.,
dissenting) (citing Geier v. Am. Honda Motor Co., 529
U.S. 861 (2000)); see also Geier, 529 U.S. at 906–07
(Stevens, J., dissenting) (“[T]he Court simply ignores
the presumption [against preemption].”).
Two years after Wyeth, however, a plurality of
this Court rejected the presumption explaining that
the presumption against preemption conflicts with
the text of the Supremacy Clause. See Mensing, 564
U.S. at 621–24; see also id. at 642 (Sotomayor, J., dissenting) (“The plurality’s new theory of the Supremacy Clause is a direct assault on” the presumption
against preemption); Bartlett, 570 U.S. at 497–98 &
n.1 (Sotomayor, J., dissenting) (noting that the presumption was “conspicuously absent from the majority opinion”).
14
This Court’s recent implied preemption cases
have not invoked the presumption. See, e.g., Kansas,
589 U.S. 191; Va. Uranium, 587 U.S. 761. Rather than
end the presumption, this Court has seemingly given
the presumption against preemption the silent treatment. Cf. Loper Bright Enters. v. Raimondo, 603 U.S.
369, 406 (2024) (“This Court, for its part, has not deferred to an agency interpretation under Chevron
since 2016.”).
***
Notably, the considerable confusion in this
Court’s caselaw is only about whether the presumption is even a legitimate canon of construction. Confusion about how the presumption applies compounds
the uncertainty.
The presumption’s proper domain raises its own
difficult questions and generates conflicting answers:
what qualifies as an area of traditional state concern?
Cf. Garcia v. San Antonio Metro. Transit Auth., 469
U.S. 528, 531 (1985) (rejecting the “traditional governmental function” test as “unworkable”). At what level
of generality does one even frame that question? And
how strong is the presumption anyway? The presumption requires a “clear and manifest” purpose evinced
from the text. But “how clear is clear?” Loper Bright,
603 U.S. at 408 (cleaned up). And how can implied
preemption ever be “clear and manifest”? “We are no
closer to an answer to that question than we were four
decades ago.” Id.
15
B. Lower Courts Are Confused
Despite this Court’s recent silence, this Court’s
cases applying the presumption against preemption
“remain[] on the books. So litigants must continue to
wrestle with it.” Loper Bright, 603 U.S. at 406; Cal.
Rest. Ass’n, 89 F.4th at 1108 (O’Scannlain, J., concurring) (“As an inferior-court judge—bound to respect
Supreme Court and Ninth Circuit precedent—I have
great difficulty in deciding how to read the Supreme
Court’s instructions here.”).
1. In express preemption cases, lower courts are
divided over whether, after Franklin, the presumption against preemption still applies. Most federal circuit courts have taken the broad view of Franklin,
holding that the presumption no longer applies.6 But
the Second and Third Circuits have read Franklin
narrowly, and continue to rely upon the presumption
in their decisions.7 For example, the Third Circuit has
said that Franklin is irrelevant because it arose in the
6
See Carson v. Monsanto Co., 72 F.4th 1261, 1267 (11th Cir.
2023); Medicaid & Medicare Advantage Prods. Ass’n of P.R., Inc.
v. Emanuelli Hernández, 58 F.4th 5, 11–12 (1st Cir. 2023); Dialysis Newco, Inc. v. Cmty. Health Sys. Grp. Health Plan, 938 F.3d
246, 258–59 (5th Cir. 2019); Air Evac EMS, Inc. v. Cheatham,
910 F.3d 751, 761–62 & n.1 (4th Cir. 2018); Watson v. Air Methods Corp., 870 F.3d 812, 817 (8th Cir. 2017) (en banc); EagleMed
LLC v. Cox, 868 F.3d 893, 903 (10th Cir. 2017); Atay v. County of
Maui, 842 F.3d 688, 699 (9th Cir. 2016).
7
See Council for Responsible Nutrition v. James, 159 F.4th 155,
171 & n.8 (2d Cir. 2025); Shuker v. Smith & Nephew, PLC, 885
F.3d 760, 771 & n.9 (3d Cir. 2018).
16
context of bankruptcy, not a case involving a “historic
police power.” Shuker, 885 F.3d at 771 n.9. State
courts, for their part, often ignore the teaching of
Franklin and liberally apply the presumption against
preemption to narrow the reach of federal statutes.8
Circuit judges have pointed out the doctrinal disarray
in Franklin’s wake.9
2. In implied preemption cases, some courts are
“unable to assess the current scope or existence of the
presumption against preemption.” Lofton v. McNeil
Consumer & Specialty Pharms., 672 F.3d 372, 378
(5th Cir. 2012). Other courts continue applying the
presumption, despite the Court’s decadelong silence
on the issue and the Mensing plurality repudiating
the presumption.10
8
See, e.g., Happel v. Guilford Cnty. Bd. of Educ., 913 S.E.2d 174,
203–04 (N.C. 2025) (Riggs, J., dissenting) (pointing out that the
majority ignored Franklin); see also Kaipust v. Echo Glob. Logistics, Inc., 271 N.E.3d 1066, 1073 (Ill. App. Ct. 2025) (acknowledging Franklin but insisting that “courts should defer to the presumption that Congress did not intend” to displace state law).
9
See Cal. Rest. Ass’n, 89 F.4th at 1110 (O’Scannlain, J., concurring) (noting that “the [Franklin] Court … left much room for
confusion”); Cheatham, 910 F.3d at 762 n.1 (Wilkinson, J.) (noting this Court’s “somewhat varying pronouncements on presumptions in express preemption cases”).
10
See, e.g., Fenner v. Gen. Motors, LLC, 113 F.4th 585, 593–94
(6th Cir. 2024); Mont. Med. Ass’n v. Knudsen, 119 F.4th 618, 623
(9th Cir. 2024); Marrache v. Bacardi U.S.A., Inc., 17 F.4th 1084,
1094–95 (11th Cir. 2021); Bedoya v. Am. Eagle Express Inc., 914
F.3d 812, 817–18 (3d Cir. 2019).
17
3. The inconsistencies across lower courts in applying the presumption against preemption are in full
display in this case and parallel litigation.
In the decision below, the Missouri Court of Appeals relied upon the presumption to hold that FIFRA
does not preempt a failure-to-warn claim alleging that
Monsanto should have warned about the risk of cancer. Pet. App. 4. So has the Ninth Circuit. See Hardeman v. Monsanto Co., 997 F.3d 941, 958 (9th Cir.
2021) (favorably citing Bates’s invocation of the presumption). Yet, the Ninth Circuit has repeatedly jettisoned the presumption in express preemption cases
after Franklin.11
Meanwhile, in another parallel case, the Third
Circuit did not rely upon the presumption against
preemption when it held that FIFRA preempts a
Pennsylvania failure-to-warn claim. See Schaffner,
113 F.4th 364.12 But ironically, the Third Circuit ad-
11
See, e.g., Int’l Bhd. of Teamsters, Loc. 2785 v. Fed. Motor Carrier Safety Admin., 986 F.3d 841, 853 (9th Cir. 2021); Nat’l R.R.
Passenger Corp. v. Su, 41 F.4th 1147, 1153 n.1 (9th Cir. 2022);
R.J. Reynolds Tobacco Co. v. County of Los Angeles, 29 F.4th 542,
553 n.6 (9th Cir. 2022); Connell v. Lima Corp., 988 F.3d 1089,
1097 (9th Cir. 2021); Atay, 842 F.3d at 699.
12
Although the Eleventh Circuit concluded that FIFRA did not
preempt Georgia state-law failure-to-warn claims, the panel at
least properly chose to employ “ordinary principles of statutory
interpretation” instead of the presumption against preemption.
See Carson v. Monsanto Co., 92 F.4th 980, 989 (11th Cir. 2024)
(cleaned up).
18
heres to the view that the presumption continues to
apply in express preemption cases.13
This case is therefore an ideal vehicle to clarify
that Franklin abrogated the presumption against
preemption in express preemption cases. But the
Court should go further and abandon the presumption
in all preemption cases because the presumption
lacks a basis in the Constitution, principles of statutory interpretation, or early judicial methods of interpreting the Clause. Abrogating the presumption
would help clear up the “muddle” of preemption doctrine, Nelson, supra, at 232, for “the lower courts,
which depend on this Court’s guidance, and to litigants, who must conform their actions to the Court’s
interpretation of federal law,” Altria Grp., 555 U.S. at
98 (Thomas, J., dissenting).
II.
THE PRESUMPTION AGAINST PREEMPTION
DEFIES THE CONSTITUTION, TEXTUALISM, AND
HISTORY
1. As Professor Nelson has persuasively argued,
the presumption against preemption has no basis in
the U.S. Constitution. See Nelson, supra, at 293–94.
To the contrary, the Supremacy Clause “instructs
courts that in the absence of other indications, they
should not automatically assume that Congress in-
13
See, e.g., Shuker, 885 F.3d at 771 & n.9; Lupian v. Joseph Cory
Holdings, LLC, 905 F.3d 127, 132 (3d Cir. 2018); Klotz v. Celentano Stadtmauer & Walentowicz LLP, 991 F.3d 458, 463 (3d Cir.
2021).
19
tends to avoid contradicting state laws.” Id. at 294
(emphasis added).
The Supremacy Clause provides:
This Constitution, and the Laws of the
United States which shall be made in Pursuance thereof; and all Treaties made, or
which shall be made, under the Authority of
the United States, shall be the supreme Law
of the Land; and the Judges in every State
shall be bound thereby, any Thing in the
Constitution or Laws of any State to the
Contrary notwithstanding.
U.S. Const. art. VI, cl. 2.
The Supremacy Clause is a decidedly pro-nationalist clause. As Professor Nelson has explained, and
Members of this Court have recognized, the phrase
“any [state law] to the Contrary notwithstanding” is a
non obstante clause. Nelson, supra, at 238–40 nn.43–
44; Mensing, 564 U.S. at 621–22. At the Founding,
such a provision meant “that the statute might contradict prior law and instructed courts not to apply the
general presumption against implied repeals.” Mensing, 564 U.S. at 622 (cleaned up). Thus, “[r]ather than
straining the new statute in order to harmonize it
with” state law—a feature of the presumption against
preemption—courts should “give the [federal] statute
its natural meaning and [] let the chips fall where they
may.” Nelson, supra, at 242.
2. The presumption against preemption is also “in
significant tension with textualism” because it “in-
20
struct[s] a court to adopt something other than the
statute’s most natural meaning.” Biden v. Nebraska,
600 U.S. 477, 509 (2023) (Barrett, J., concurring)
(cleaned up).
This is no less true in implied preemption cases,
see Wyeth, 555 U.S. at 624 & n.14 (Alito, J., dissenting), than in express preemption cases, Franklin, 579
U.S. at 125. Whatever the scope of implied preemption, courts should use “the accepted methods of interpretation” in all preemption cases. Kansas, 589 U.S.
at 214 (Thomas, J., concurring).
3. Historical support for the presumption against
preemption is also lacking in early judicial methods of
interpreting the Clause. This Court did not invoke the
presumption in its earliest preemption cases. See, e.g.,
Gibbons v. Ogden, 22 U.S. (9 Wheat.) 1 (1824); Mayor
of New York v. Miln, 36 U.S. (11 Pet.) 102 (1837). Nor
is there a “discussion of any canon applicable to questions of preemption in nineteenth century legal treatises.” Barrett, supra, at 153 n.211; see also Viet D.
Dinh, Federal Displacement of State Law: The Nineteenth Century View, in Federal Preemption: States’
Powers, National Interests 27 (Richard A. Epstein &
Michael S. Greve eds., 2007) (explaining the early history).
Justice Barrett has suggested that perhaps Cohens v. Virginia “can be read as an early statement of
the presumption against preemption.” Barrett, supra,
at 153. But that is not the best reading. In Cohens v.
Virginia, the Court addressed whether a District of
Columbia lottery law vested the District of Columbia
21
Corporation with power to sell lottery tickets in Virginia despite a law prohibiting lotteries in Virginia. 19
U.S. (6 Wheat.) 264, 441 (1821). The Court said no,
because presuming that Congress vested a local municipal corporation with extraterritorial authority to
displace penal laws in neighboring states would be
surprising, and such a surprising delegation would be
“clearly and unequivocally expressed.” Id. at 443. This
reflects not a general presumption against preemption of historic police powers, but rather the more
modest principle “that a reasonable speaker would not
understand Congress to confer an unusual form of authority without saying more.” Nebraska, 600 U.S. at
519 (Barrett, J., concurring).
The modern presumption against preemption instead originates in the New Deal’s “proregulatory
bias,” favoring “the authority of regulators and their
clientele” at every level of government, federal and
state. Greve, supra, at 211–12. The Court first announced the presumption in Mintz v. Baldwin, 289
U.S. 346 (1933), as “a reaction to the increased exercise of existing federal legislative authority.” Gardbaum, supra, at 537. The presumption against
preemption continues to be justified largely on those
policy grounds. See, e.g., Lohr, 518 U.S. at 485; Wyeth,
555 U.S. 565 n.3. Political scientists may debate
whether this kind of New Deal “federalism” protecting
states as regulators, rather than their citizens, is a
good idea. But a court’s “job is to interpret Congress’s
decrees of pre-emption neither narrowly nor broadly,
but in accordance with their apparent meaning.” Cip-
22
ollone, 505 U.S. at 544 (Scalia, J., concurring in the
judgment in part and dissenting in part).
***
The judge-made presumption against preemption
has no basis in the Constitution or early caselaw and
hamstrings courts, forcing them to give federal statutes unnatural, cramped readings at the expense of
ordinary principles of statutory interpretation. That
is true in both express and implied preemption cases.
Common sense may sometimes counsel against implying preemption in particular cases, as in Cohens, but
that doesn’t justify a normative judge-made canon
that cuts across the broad domain of concurrent powers. This Court should categorically abandon the presumption.14
III.
MISSOURI RULE’S CONTRADICTS FIFRA
Ending the confusing presumption against
preemption from precedent is a good start, but only a
start. The Court must still analyze the conflict. Here,
the conflict is straightforward because “federal law
and state law are in logical contradiction.” Glacier
Nw., Inc. v. Int’l Bhd. of Teamsters Loc. Union No.
174, 598 U.S. 771, 788 (2023) (Thomas, J., concurring
14
This change need not unsettle prior cases. If this Court abrogates the presumption, the Court could make clear that “[t]he
holdings of” prior “cases that specific [state requirements] are
lawful” would still be “subject to statutory stare decisis despite
[the Court’s] change in interpretive methodology.” Loper Bright,
603 U.S. at 412.
23
in the judgment) (cleaned up); see also Nelson, supra,
at 260–61.
1. “Sometimes … the federal statute is meant to
establish a maximum standard or requirement on
which everyone can rely, so that, for example, manufacturers serving a national market will not be compelled to comply with the law of the most restrictive
state.” Scalia & Garner, supra, at 290. FIFRA is such
a law for pesticide labeling. Under FIFRA, EPA must
weigh the health risks and benefits of a label, to ensure that the label is “just right.” See 7 U.S.C
§ 136(q)(1)(G), (x). Additional labeling requirements
are logically inconsistent with such a Goldilocks balancing scheme. See Robert R. Gasaway & Ashley C.
Parrish, The Problem of Federal Preemption: Toward
a Formal Solution, in Federal Preemption, supra, at
219.
FIFRA’s text confirms this logic by forbidding
state laws that impose “any requirements for labeling
or packaging in addition to or different from those required under” FIFRA. 7 U.S.C. § 136v(b). That text resolves this case. Durnell’s failure-to-warn claim imposes “requirements for labeling,” and the label he
seeks would be different from Monsanto’s EPA’sapproved label “under” FIFRA, which contains no
such warning. Pet. Br. 26–27.
Durnell, like some lower courts, tries to make this
case more complicated than it really is. Durnell claims
that EPA’s-approved label is not a “requirement” under FIFRA because the label is not a regulation or a
complete defense in a misbranding enforcement pro-
24
ceeding. Br. in Opp. 25–27. That argument fails.
EPA’s registration is a binding licensing order, and
the label is a condition of the license: selling the product without the label would make the product misbranded. U.S. Br. 13–14. It doesn’t matter that this
labeling requirement is necessary, but not sufficient,
to prove compliance with FIFRA. What matters is that
the label is a requirement.
Equally unavailing is the reasoning of the Missouri Court of Appeals. The Missouri Court of Appeals
oddly reasoned that Missouri law is no different from
FIFRA because FIFRA and Missouri law share the
same general purpose: adequately warning the public
about health risks. Pet. App. 6–7.
But of course, that Missouri law shares the same
general purpose is quite different from imposing the
same specific requirements on regulated parties. The
Missouri Court of Appeals’ preemption analysis is the
flipside of the kind of “freewheeling” obstacle preemption routinely condemned by some Members of this
Court: The Missouri Court of Appeals focused on the
broad purpose of federal and state law to avoid a conflict, rather than to create one. Kansas, 589 U.S. at
214 (Thomas, J., concurring). Virtually any statute
can be recast in vague generalities to avoid a conflict,
so this Court should reject this flawed framing tactic.
25
CONCLUSION
Missouri’s failure-to-warn claim is “repugnant to
a law of the United States, made in pursuance of the
constitution, and, therefore, void.” Osborn v. Bank of
the United States, 22 U.S. (9 Wheat.) 738, 868 (1824).
This Court should reverse.
Respectfully submitted,
Michael Buschbacher
James R. Conde
Counsel of Record
Walker Fortenberry
BOYDEN GRAY PLLC
800 Connecticut Ave. NW
Suite 900
Washington, DC 20006
(202) 955-0620
jconde@boydengray.com
March 2, 2026
This is a copy of a public record, reproduced as it was published. It is not legal advice, and it may not be the version a court would rely on. Check the official source before you cite it.