Amicus Curiae Brief — Shelby County, Iowa, et al., Petitioners v. William Couser, et al.

No. 25-419

IN THE

Supreme Court of the United States

SHELBY COUNTY, IOWA, ET AL.,

v.

Petitioners,

WILLIAM COUSER AND

SUMMIT CARBON SOLUTIONS, LLC,

Respondents.

On Petition for Writ of Certiorari

to the United States Court of Appeals

for the Eighth Circuit

BRIEF OF PREEMPTION LAW PROFESSORS

AS AMICI CURIAE

IN SUPPORT OF PETITIONERS

Dated: November 6, 2025

BATEMAN & SLADE, INC.

JONATHAN S. MASSEY

Counsel of Record

CHISEUL KYLIE KIM

AUSTIN S. MARTIN

MASSEY & GAIL LLP

1000 Maine Ave. SW

Suite 450

Washington, D.C. 20024

(202) 652-4511

jmassey@masseygail.com

kkim@masseygail.com

amartin@masseygail.com

STONEHAM, MASSACHUSETTS

TABLE OF CONTENTS

TABLE OF AUTHORITIES ..................................... iii

INTEREST OF AMICI CURIAE ............................... 1

SUMMARY OF ARGUMENT.................................... 2

ARGUMENT .............................................................. 3

I.

A Legislative-Motive Inquiry Here Would

Be Unique in Preemption Doctrine and an

Outlier in Constitutional Doctrine

Generally ......................................................... 5

A.

This Court Has Consistently Held That

States’

Intent

Is

Irrelevant

to

Preemption ................................................. 5

B.

Judicial Scrutiny of Legislative Motive Is

Disfavored in Constitutional Law

Generally .................................................. 11

II.

Preemption Should Not Turn On State and

Local Legislative Intent Beyond the

Statutory Text ............................................... 14

A.

Inquiring Into Extra-Textual Legislative

Intent Raises Serious Conceptual

Problems ................................................... 14

B.

Inquiring Into Extra-Textual Legislative

Intent Raises Serious Practical Problems

.................................................................. 15

C.

Inquiring Into Extra-Textual Legislative

Intent Raises Serious Federalism

Problems ................................................... 19

i

III.

The Pipeline Safety Act Does Not Require A

Motive Inquiry ............................................... 22

CONCLUSION ......................................................... 24

ii

TABLE OF AUTHORITIES

Cases

Alessi v. Raybestos-Manhattan, Inc.,

451 U.S. 504 (1981)............................................ 10

Arizona v. United States,

567 U.S. 387 (2012)........................................ 8, 19

AT&T Mobility LLC v. Concepcion,

563 U.S. 333 (2011).............................................. 8

Atlantic Richfield Co. v. Christian,

590 U.S. 1 (2020).................................................. 5

Church of the Lukumi Babalu Aye, Inc. v.

City of Hialeah,

508 U.S. 520 (1993)............................................ 13

City of Rancho Palos Verdes v. Abrams,

544 U.S. 113 (2005)............................................ 23

Colorado Anti-Discrimination Comm’n v.

Continental Air Lines, Inc.,

372 U.S. 714 (1963).............................................. 9

Couser v. Shelby Cnty.,

139 F.4th 664 (8th Cir. 2025) ...................... 16, 21

Crosby v. Nat’l Foreign Trade Council,

530 U.S. 363 (2000).............................................. 8

CSX Transp., Inc. v. Easterwood,

507 U.S. 658 (1993)............................................ 22

Edwards v. Aguillard,

482 U.S. 578 (1987)...........................14, 17, 18, 19

Engine Mfrs. Ass’n v. S. Coast Air Quality

Mgmt. Dist.,

541 U.S. 246 (2004).............................................. 4

iii

Fla. Lime & Avocado Growers, Inc. v. Paul,

373 U.S. 132 (1963).............................................. 9

Fletcher v. Peck,

10 U.S. (6 Cranch) 87 (1810) ............................. 11

Free v. Bland,

369 U.S. 663 (1962).............................................. 9

Gade v. National Solid Wastes Mgmt.

Association,

505 U.S. 88 (1992).............................................. 11

Gibbons v. Ogden,

22 U.S. (9 Wheat.) 1 (1824) ................................. 9

Gobeille v. Liberty Mutual Insurance Co.,

577 U.S. 312 (2016)........................................... 11

Hill v. Florida ex rel. Watson,

325 U.S. 538 (1945).............................................. 9

Hillsborough Cnty. v. Automated Med.

Lab’ys, Inc.,

471 U.S. 707 (1985).............................................. 4

Hines v. Davidowitz,

312 U.S. 52 (1941)................................................ 9

Hughes v. Oklahoma,

441 U.S. 322 (1979)............................................ 10

Hughes v. Talen Energy Mktg., LLC,

578 U.S. 150 (2016)........................................ 8, 13

International Paper Co. v. Ouellette,

479 U.S. 481 (1987)............................................ 10

Kansas v. Garcia,

589 U.S. 191 (2020 ............................................... 5

Kennedy v. Bremerton Sch. Dist.,

597 U.S. 507 (2022)............................................ 12

iv

Kesler v. Department of Public Safety,

369 U.S. 153 (1962).................................... 8, 9, 10

Kurns v. R.R. Friction Prods. Corp.,

565 U.S. 625 (2012).............................................. 8

Lacoste v. Dep’t of Conservation of La.,

263 U.S. 545 (1924)............................................ 10

Lemon v. Kurtzman,

403 U.S. 602 (1971)............................................ 12

Lomax v. Ortiz-Marquez,

140 S. Ct. 1721 (2020).................................... 8, 23

Mackey v. Lanier Collection Agency &

Service, Inc.,

486 U.S. 825 (1988)............................................ 10

Napier v. Atl. Coast Line R.R. Co.,

272 U.S. 605 (1926).............................................. 9

Nash v. Fla. Indus. Comm’n,

389 U.S. 235 (1967).............................................. 9

New York Times Co. v. Sullivan,

376 U.S. 254 (1964)............................................ 20

Oklahoma v. Castro-Huerta,

597 U.S. 629 (2022)........................................ 5, 23

Oneok, Inc. v. Learjet, Inc.,

575 U.S. 373 (2015).............................................. 4

Pacific Gas & Elec. Co. v. State Energy Res.

Conservation & Dev. Comm’n,

461 U.S. 190 (1983).............................7, 14, 17, 22

Palmer v. Thompson,

403 U.S. 217 (1971)............................................ 12

Perez v. Campbell,

402 U.S. 637 (1971)........................................ 9, 10

v

Personnel Adm’r v. Feeney,

442 U.S. 256 (1979)............................................ 13

Reitz v. Mealey,

314 U.S. 33 (1941)...................................... 8, 9, 10

Sears, Roebuck & Co. v. Stiffel Co.,

376 U.S. 225 (1964).............................................. 9

Shady Grove Orthopedic Assocs., P.A. v.

Allstate Ins. Co.,

559 U.S. 393 (2010)..... 3, 5, 6, 8, 14, 16, 18, 19, 23

Shaw v. Reno,

509 U.S. 630 (1993)............................................ 13

Silkwood v. Kerr-McGee Corp.,

464 U.S. 238 (1984).............................................. 6

Smith v. Iowa Dist. Ct. for Polk Cnty.,

3 N.W.3d 524 (Iowa 2024) ................................. 20

Sola Elec. Co. v. Jefferson Elec. Co.,

317 U.S. 173 (1942).............................................. 9

Tenney v. Brandhove,

341 U.S. 367 (1951)............................................ 12

Tex. Midstream Gas Servs. v. City of Grand

Prairie,

608 F.3d 200 (5th Cir. 2010) ............................. 16

United States v. Gillock,

445 U.S. 360 (1980)............................................ 20

United States v. O’Brien,

391 U.S. 367 (1968)................................ 12, 14, 16

Village of Arlington Heights v. Metro. Hous.

Dev. Corp.,

429 U.S. 252 (1977)............................................ 13

vi

Virginia Uranium, Inc. v. Warren,

587 U.S. 761 (2019)..... 3, 6, 7, 8, 13, 15, 18, 22, 23

Wallace v. Jaffree,

472 U.S. 38 (1985).............................................. 13

Washington Gas Light Co. v. Prince George’s

Cnty. Council,

711 F.3d 412 (4th Cir. 2013) ............................. 16

Wyeth v. Levine,

555 U.S. 555 (2009).............................................. 4

Statutes

42 U.S.C. § 2021 ................................................... 7, 23

47 U.S.C. § 332 ......................................................... 23

49 U.S.C. § 60104 ......................................... 21, 22, 23

Constitutional Provisions

U.S. Const. art. I, § 6, cl. 1 ....................................... 20

Other Authorities

2 Joseph Story, Commentaries on the

Constitution of the United States 533

(Boston, Hilliard, Gray & Co. 1833).................. 14

Caleb Nelson, What Is Textualism?, 91 Va. L.

Rev. 347 (2005) .................................................. 15

John F. Manning, Textualism and Legislative

Intent, 91 Va. L. Rev. 419 (2005)....................... 15

Jose R. Torres & Steve Windsor, State

Legislative Histories: A Select, Annotated

Bibliography, 85 L. Lib. J. 545 (1993) .............. 18

Joshua Macey, Long Live The Federal Power

Act’s Bright Line, 134 Harv. L. Rev. 1360

(2021).................................................................... 2

vii

Kenneth A. Shepsle, Congress Is a “They,” Not

an “It”: Legislative Intent as Oxymoron, 12

Int’l Rev. L. & Econ. 239 (1992) ........................ 14

Laurence H. Tribe, The Mystery of Motive,

Private and Public: Some Notes Inspired by

the Problems of Hate Crime and Animal

Sacrifice, 1993 Sup. Ct. Rev. 1 .......................... 18

Matthew R. Christiansen & Joshua C. Macey,

Long Live the Federal Power Act’s Bright

Line, 134 Harv. L. Rev. 1360 (2021) ................. 13

Michael J. Klarman, An Interpretive History of

Modern Equal Protection, 90 Mich. L. Rev.

213 (1991) ........................................................... 12

Richard H. Fallon, Jr., Constitutionally

Forbidden Legislative Intent, 130 Harv. L.

Rev. 523 (2016) ...........................11, 12, 13, 15, 18

Richard L. Hasen, Bad Legislative Intent, 2006

Wis. L. Rev. 843 ................................................. 18

Robert C. Farrell, Legislative Purpose and Equal

Protection’s Rationality Review, 37 Vill. L.

Rev. 1 (1992) ...................................................... 15

Ronald Dworkin, Law’s Empire, 321 (Harv. Univ.

Press, 1986) ........................................................ 15

Roy M. Mersky & Donald J. Dunn,

Fundamentals of Legal Research 233 (8th ed.

2002) ................................................................... 18

William Funk, Judicial Deference and

Regulatory Preemption by Federal Agencies,

84 Tul. L. Rev. 1233 (2010) ................................. 1

viii

William Funk, Preemption by Federal Agency

Action, in Preemption Choice: The Theory,

Law, and Reality of Federalism’s Core

Question 214 (William W. Buzbee ed.,

Cambridge Univ. Press 2009) ............................. 1

ix

INTEREST OF AMICI CURIAE 1

Amici are law professors who specialize in

preemption

law,

constitutional

law,

and/or

administrative law. Through their academic work

and litigation experience, amici are knowledgeable

about the issues in this case. Amici agree with

Petitioners that the Eighth Circuit’s decision below

creates a circuit split on an important issue of federal

preemption. Pet. 13–18, 27–32. They write to amplify

Petitioners’ arguments (id. at 25–27) that the decision

below also conflicts with this Court’s precedents on

the proper function of state legislative intent in

preemption analysis. That conflict heightens the

need for certiorari.

•

William Funk is the Lewis & Clark

Distinguished Professor of Law, Emeritus, at Lewis &

Clark Law School. His publications include Judicial

Deference and Regulatory Preemption by Federal

Agencies, 84 Tul. L. Rev. 1233 (2010), and Preemption

by Federal Agency Action, in Preemption Choice: The

Theory, Law, and Reality of Federalism’s Core

Question 214 (William W. Buzbee ed., Cambridge

Univ. Press 2009).

Pursuant to Supreme Court Rule 37.6, counsel for amici

represent that they authored this brief in its entirety and that

none of the parties or their counsel, nor any other person or

entity other than amici or their counsel, made a monetary

contribution intended to fund the preparation or submission of

this brief. Pursuant to Rule 37.2, counsel for amici also

represent that all counsel of record received timely notice of the

intent to file this brief.

1

1

•

Joshua Macey is an Associate Professor of Law

at Yale Law School. In the context of work on

bankruptcy, environmental law, energy law, and the

regulation of financial institutions, he has taught and

written on preemption law, constitutional law, and

administrative law. Notable publications in those

areas include Long Live The Federal Power Act’s

Bright Line, 134 Harv. L. Rev. 1360 (2021).

•

Sidney A. Shapiro is the Frank U. Fletcher

Chair in Administrative Law at Wake Forest

University School of Law. As a leading expert in

administrative procedure and regulatory policy, he

has written ten books, contributed chapters to seven

additional books, and authored or coauthored more

than 55 articles.

•

Brian Wolfman is a Professor from Practice

and the Director of the Appellate Courts Immersion

Clinic at Georgetown University Law Center. In

addition to his extensive litigation experience on

preemption issues (including before this Court),

Professor Wolfman has often written on the

intersection of state tort law and federal preemption

doctrine.

SUMMARY OF ARGUMENT

Legislative-motive inquiries have no place in

this Court’s Supremacy Clause jurisprudence.

Preemption in this case should not turn on the

motivations of the officials who enacted Shelby

County’s and Story County’s pipeline setbacks. In no

area of preemption doctrine does the result turn on

the purpose of state or local legislation rather than its

2

effects. Likewise, in the converse scenario, this Court

has explicitly held that a benign state purpose (i.e., a

purpose not to obstruct federal law) cannot save a

state statute that has the effect of being an obstacle

to Congress’s goals. The Eighth Circuit’s approach

would thus create an unjustified aberration in

preemption doctrine by requiring a probing, invasive

inquiry into the minds of state and local legislators.

Legislative-motive

inquiries

are

also

anomalous in constitutional doctrine beyond

preemption. This Court has shown a distinct aversion

to considering legislative purpose and has typically

done so only in narrow areas like equal protection and

the Establishment Clause. Even in those contexts, an

illicit motive generally cannot, standing alone, render

a law unconstitutional. The Eighth Circuit’s decision

not only departs from longstanding preemption

doctrine but adopts a mode of analysis that is highly

disfavored in modern constitutional law generally.

The Court’s reluctance to inquire into

legislative motive is well justified. As this Court

recently explained, such inquiries raise intractable

conceptual and practical problems. See Virginia

Uranium, Inc. v. Warren, 587 U.S. 761, 776 (2019)

(plurality); Shady Grove Orthopedic Assocs., P.A. v.

Allstate Ins. Co., 559 U.S. 393, 404 (2010). In the

preemption context, such an inquiry also poses a

serious threat to federalism. This Court should grant

the Petition for Writ of Certiorari.

ARGUMENT

Of the three types of preemption this Court has

identified—express, field, and conflict preemption—

only express and field preemption are at issue in this

3

case. Express preemption cases “begin with the

language employed by Congress and the assumption

that the ordinary meaning of that language

accurately expresses the legislative purpose.” Engine

Mfrs. Ass’n v. S. Coast Air Quality Mgmt. Dist., 541

U.S. 246, 252 (2004) (internal quotation marks and

citation omitted). The question in field preemption

cases is whether Congress “intended to foreclose any

state regulation in the area, irrespective of whether

state law is consistent or inconsistent with federal

standards.” Oneok, Inc. v. Learjet, Inc., 575 U.S. 373,

377 (2015) (internal quotation marks and citation

omitted). As “[i]n all pre-emption cases,” fieldpreemption analysis begins “with the assumption

that the historic police powers of the States were not

to be superseded by the Federal Act unless that was

the clear and manifest purpose of Congress.” Wyeth

v. Levine, 555 U.S. 555, 565 (2009) (alteration in

original); see also Hillsborough Cnty. v. Automated

Med. Lab’ys, Inc., 471 U.S. 707, 713 (1985) (“[F]or the

purposes

of

the

Supremacy

Clause,

the

constitutionality of local ordinances is analyzed in the

same way as that of statewide laws.”).

4

I.

A Legislative-Motive Inquiry Here

Would Be Unique in Preemption

Doctrine

and

an

Outlier

in

Constitutional Doctrine Generally

A.

This Court Has Consistently Held

That States’ Intent Is Irrelevant

to Preemption

1. Preemption analysis has traditionally

focused on what the state actually did, not why it did

it. The Court’s decision in Shady Grove is illustrative.

There, it did not matter what the state legislature

might have intended to do or “[t]he manner in which

the law could have been written . . . ; what matter[ed]

[wa]s the law the legislature did enact.” 559 U.S. at

403 (internal quotation marks omitted). See also

Oklahoma v. Castro-Huerta, 597 U.S. 629, 642 (2022)

(“As this Court has repeatedly stated, the text of a law

controls over purported legislative intentions

unmoored from any statutory text.”) (citation

omitted); cf. Kansas v. Garcia, 589 U.S. 191, 202

(2020) (“‘There is no federal preemption in vacuo,’

without a constitutional text, federal statute, or

treaty made under the authority of the United

States.”) (citation omitted); Atlantic Richfield Co. v.

Christian, 590 U.S. 1, 37 (2020) (Gorsuch, J.,

concurring) (“[A] party . . . seeking to displace state

law must identify a constitutional text or a federal

statute’ that does the displacing.”) (internal quotation

marks and citation omitted).

Shady Grove went on to explain some of the

fundamental problems that would arise from a

legislative-motive-based approach to preemption. For

one thing, it would produce arbitrary outcomes:

5

“[O]ne State’s statute could survive pre-emption . . .

while another State’s identical law would not, merely

because its authors had different aspirations.” 559

U.S. at 404. For another, it would be unfriendly to

“state prerogatives” to look into motive and identify

“[t]he manner in which the law ‘could have been

written’” rather than simply accepting what the state

“[l]egislature did enact.” Id. at 403–04 (citation

omitted) . For yet another, it would raise tremendous

practical problems for courts. “Many laws further

more than one aim, and the aim of others may be

impossible to discern.” Id. at 404. Trial courts would

nonetheless have to attempt “to discern, in every

[relevant] case, the purpose behind any putatively

pre-empted state . . . rule.” Id. That “task w[ould]

often prove arduous”; “[h]ard cases” would “abound”;

and “federal judges would be condemned to poring

through state legislative history—which may be less

easily obtained, less thorough, and less familiar than

its federal counterpart.” Id. at 404–05.

Virginia Uranium is likewise illustrative.

There, the Court addressed a similar preemption

argument that only the federal agency could issue

safety-motivated regulations; the lead opinion

declined inquiry into state legislative purpose and

emphasized that any attempt to “glean” such

purposes should be limited to review of the state’s

“statutory text.” 587 U.S. at 777. Speaking to

Silkwood v. Kerr-McGee Corp., 464 U.S. 238 (1984),

which refused to find preemption by the same federal

statute, Virginia Uranium acknowledged that, “if the

Silkwood Court had inquired into state legislative

purposes,” it may have found the state tort law

“harder to sustain” because state tort laws “plainly

intend to regulate public safety.” 587 U.S. at 774.

6

Virginia Uranium described the “costs to

cooperative federalism and individual liberty” were

courts to embark on an invasive inquiry into state

legislative purpose: “The natural tendency of regular

federal judicial inquiries into state legislative

intentions would be to stifle deliberation in state

legislatures and encourage resort to secrecy and

subterfuge.” Id. at 775. The opinion further detailed

“conceptual and practical” concerns:

“State

legislatures are composed of individuals who often

pursue legislation for multiple and unexpressed

purposes, so what legal rules should determine when

and how to ascribe a particular intention to a

particular legislator? What if an impermissible

intention existed but wasn’t necessary to her vote?

And what percentage of the legislature must harbor

the impermissible intention before we can impute it

to the collective institution?” Id. at 776. Also,

practically speaking, “how are courts supposed to

conduct a reasonable inquiry into these questions

when recorded state legislative history materials are

often not as readily available or complete as their

federal counterparts?” Id. at 777.

While the dissent in Virginia Uranium

advocated for the need to assess state legislative

purpose, it did so in the specific context of the Atomic

Energy Act. See id. at 801 (Roberts, C.J., dissenting).

“[T]he text of the [Atomic Energy Act]” expressly

“recognizes that States continue to have authority ‘to

regulate activities for purposes other than protection

against radiation hazards,’” id. at 801 (quoting 42

U.S.C. § 2021((k)), so the dissent felt bound by that

language and precedent, see id. (“The statute and our

precedent [in Pacific Gas & Elec. Co. v. State Energy

Res. Conservation & Dev. Comm’n, 461 U.S. 190

7

(1983)] plainly require . . . [a purpose-based]

approach here.”). The Pipeline Safety Act (“PSA”)

does not contain language inviting a judicial inquiry

into state or local legislative purpose, so there is no

basis to engage in one. Nor should courts read in such

language, as it would impermissibly “narrow” the

PSA’s express preservation of state and local

authority “by inserting words Congress chose to

omit.” Lomax v. Ortiz-Marquez, 140 S. Ct. 1721, 1725

(2020).

2. Shady Grove and Virginia Uranium are just

two in a pedigreed line of authority, covering a wide

range of federal statutes, all with the same punchline:

the “purpose” of a state law (to say nothing of its

legislators’ subjective motivations) is not relevant in

preemption analysis. No area of modern preemption

doctrine works otherwise—not mining, Virginia

Uranium, 587 U.S. 761; not energy, Hughes v. Talen

Energy Mktg., LLC, 578 U.S. 150 (2016); not

immigration, Arizona v. United States, 567 U.S. 387

(2012); not railroads, Kurns v. R.R. Friction Prods.

Corp., 565 U.S. 625 (2012); not arbitration, AT&T

Mobility LLC v. Concepcion, 563 U.S. 333 (2011); not

civil procedure, Shady Grove, 559 U.S. 393; and not

foreign affairs, Crosby v. Nat’l Foreign Trade Council,

530 U.S. 363 (2000). See also Virginia Uranium, 587

U.S. at 774–75 (listing cases).

Indeed, almost 50 years ago, this Court

expressly overruled an earlier approach to

preemption that turned on the purpose of state law.

In Kesler v. Department of Public Safety, 369 U.S. 153

(1962), and Reitz v. Mealey, 314 U.S. 33 (1941), the

Court had upheld state laws that—by leaving debts

arising from car accidents in place regardless of

bankruptcy—interfered with the goal of federal

8

bankruptcy law to give debtors a clean slate. The

Court in those cases reasoned that the state laws were

not preempted because their purposes were to

promote road safety, rather than to provide relief to

creditors. See Kesler, 369 U.S. at 174; Reitz, 314 U.S.

at 37.

That approach ended in Perez v. Campbell, 402

U.S. 637 (1971), in which the Court held that it would

“no longer adhere to the aberrational doctrine of

Kesler and Reitz that state law may frustrate the

operation of federal law as long as the state

legislature in passing its law had some purpose in

mind other than one of frustration.” Id. at 651–52.

The purpose-driven approach of Kesler and Reitz,

Perez explained, was aberrant because it removed the

focus from the effects of the state law at issue, which

ran contrary to preemption doctrine as far back as

Chief Justice Marshall’s opinion in Gibbons v. Ogden,

22 U.S. (9 Wheat.) 1 (1824). See 402 U.S. at 649–50

(also citing Hines v. Davidowitz, 312 U.S. 52, 67

(1941); Sola Elec. Co. v. Jefferson Elec. Co., 317 U.S.

173, 176 (1942); Hill v. Florida ex rel. Watson, 325

U.S. 538, 542–43 (1945); Free v. Bland, 369 U.S. 663,

666 (1962); Colorado Anti-Discrimination Comm’n v.

Continental Air Lines, Inc., 372 U.S. 714, 722 (1963);

Sears, Roebuck & Co. v. Stiffel Co., 376 U.S. 225, 229

(1964); Nash v. Fla. Indus. Comm’n, 389 U.S. 235, 240

(1967)); see also Fla. Lime & Avocado Growers, Inc. v.

Paul, 373 U.S. 132, 141–42 (1963) (focusing on

“whether the purposes of the two laws are parallel or

divergent” tends to “obscure more than aid” in

determining whether state law is preempted by

federal law); Napier v. Atl. Coast Line R.R. Co., 272

U.S. 605, 612 (1926) (preemption analysis turns not

on whether federal and state laws “are aimed at

9

distinct and different evils” but on whether they

“operate upon the same object”). The Court thus

“conclude[d] that Kesler and Reitz can have no

authoritative effect to the extent they are inconsistent

with the controlling principle that any state

legislation which frustrates the full effectiveness of

federal law is rendered invalid by the Supremacy

Clause.” Perez, 402 U.S. at 652.

In the years since Perez, this Court has

maintained that same approach, time and again, as

litigants try to save state statutes from preemption by

pointing to benign legislative purposes. The Court

explained in Hughes v. Oklahoma, 441 U.S. 322

(1979), that “when considering the purpose of a

challenged statute, this Court is not bound by ‘[t]he

name, description or characterization given it by the

legislature or the courts of the State,’ but will

determine for itself the practical impact of the law.”

Id. at 336 (quoting Lacoste v. Dep’t of Conservation of

La., 263 U.S. 545, 550 (1924)). Alessi v. RaybestosManhattan, Inc., 451 U.S. 504 (1981), held that,

“[w]hatever the purpose or purposes of the New

Jersey statute, we conclude that it ‘relate[s] to

pension plans’ governed by [the Employee Retirement

Income Security Act of 1974 (‘ERISA’)].” Id. at 524

(internal quotation marks omitted) (second alteration

in original). The Court in International Paper Co. v.

Ouellette, 479 U.S. 481 (1987), noted that Perez stands

for the proposition that “effect rather than purpose of

a state statute governs pre-emption analysis.” Id. at

498 n.19. In Mackey v. Lanier Collection Agency &

Service, Inc., 486 U.S. 825 (1988), the Court again

reiterated the core idea of Perez: “Legislative ‘good

intentions’ do not save a state law within the broad

pre-emptive scope of [ERISA] § 514(a).” Id. at 830. In

10

Gade v. National Solid Wastes Management

Association, 505 U.S. 88 (1992), the Court similarly

held that, “[w]hatever the purpose or purposes of the

state law, pre-emption analysis cannot ignore the

effect of the challenged state action on the pre-empted

field. The key question is thus at what point the state

regulation sufficiently interferes with federal

regulation that it should be deemed pre-empted.” Id.

at 107. And in Gobeille v. Liberty Mutual Insurance

Co., 577 U.S. 312 (2016), the Court featured the nowfamiliar refrain that “[a]ny difference in purpose does

not transform this direct regulation of a central

matter of [ERISA] plan administration into an

innocuous and peripheral set of additional rules.” Id.

at 325 (citation omitted). State purpose and motive

simply have no role in preemption analysis.

B.

Judicial Scrutiny of Legislative

Motive

Is

Disfavored

in

Constitutional Law Generally

In constitutional doctrine more generally,

inquiries into legislative intent (particularly

subjective motive) are rare and increasingly

disfavored.

In the nineteenth century, this Court

“frequently rebuffed calls for judicial scrutiny of

legislative motivation.”

Richard H. Fallon, Jr.,

Constitutionally Forbidden Legislative Intent, 130

Harv. L. Rev. 523, 534 (2016). That trend began early

in our constitutional history. In Fletcher v. Peck, 10

U.S. (6 Cranch) 87 (1810), Chief Justice Marshall held

that a court of law “cannot sustain a suit . . . founded

on the allegation that the act is a nullity, in

consequence of the impure motives which influenced

11

certain members of the legislature which passed the

law.” Id. at 131.

For most of the twentieth century, legislativeintent inquiries remained both rare and restricted in

scope. 2 The 1970s marked a shift in the Court’s

willingness to probe legislative intent. See Michael J.

Klarman, An Interpretive History of Modern Equal

Protection, 90 Mich. L. Rev. 213, 284–85 (1991). The

inquiry became relevant in a limited number of

contexts, including the Equal Protection Clause, the

dormant Commerce Clause, the Establishment

Clause, and the Free Exercise Clause. See Fallon, 130

Harv. L. Rev. at 525–26. Yet even in these areas the

decisional significance of legislative intent remained

quite limited. Impermissible legislative intent was,

standing alone, sufficient to strike down a law in only

a few cases. 3

What is more, the nature of inquiries into

legislative purpose, motive, and intent has changed

even since the 1970s. Although the Court previously

See Tenney v. Brandhove, 341 U.S. 367, 377 (1951) (“The

holding of this Court in Fletcher v. Peck, that it was not

consonant with our scheme of government for a court to inquire

into the motives of legislators, has remained unquestioned.”)

(citation omitted); United States v. O’Brien, 391 U.S. 367, 383

(1968) (“It is a familiar principle of constitutional law that this

Court will not strike down an otherwise constitutional statute

on the basis of an alleged illicit legislative motive.”); Palmer v.

Thompson, 403 U.S. 217, 224 (1971) (“[N]o case in this Court has

held that a legislative act may violate equal protection solely

because of the motivations of the men who voted for it.”).

2

3 For example, Lemon v. Kurtzman, 403 U.S. 602 (1971), and its

progeny would have overturned laws solely because their

purpose was to promote religion. But see Kennedy v. Bremerton

Sch. Dist., 597 U.S. 507 (2022) (departing from Lemon).

12

considered the motives of state officials in a handful

of decisions, 4 more recent cases aim the legislativeintent inquiry at objective purpose. See Fallon, 130

Harv. L. Rev. at 541–43; Matthew R. Christiansen &

Joshua C. Macey, Long Live the Federal Power Act’s

Bright Line, 134 Harv. L. Rev. 1360, 1398–99 (2021)

(explaining that the Court’s approach to field

preemption in cases as recent as Hughes v. Talen

Energy and Virginia Uranium focuses on “the

substance of state regulations, not the subjective

motivations of the regulators who enacted them”).

This version of legislative intent may be discerned in

a manner akin to ordinary statutory interpretation,

including inferring purpose from the distinctive

effects of a law. See, e.g., Shaw v. Reno, 509 U.S. 630,

642 (1993) (striking a peculiarly shaped legislative

district that was “so extremely irregular on its face

that it rationally c[ould] be viewed only as an effort to

segregate the races for purposes of voting”).

4 See, e.g., Wallace v. Jaffree, 472 U.S. 38, 56–57 (1985) (relying

on legislative history to support a finding that the legislature

acted with a constitutionally forbidden purpose of promoting

prayer in public schools); Personnel Adm’r v. Feeney, 442 U.S.

256, 279 (1979) (stating that a “‘[d]iscriminatory purpose’ . . .

implies that [a legislature] . . . selected or reaffirmed a particular

course of action at least in part ‘because of,’ not merely ‘in spite

of,’ its adverse effects upon an identifiable group”) (citation

omitted); Village of Arlington Heights v. Metro. Hous. Dev. Corp.,

429 U.S. 252, 265–66 (1977); Church of the Lukumi Babalu Aye,

Inc. v. City of Hialeah, 508 U.S. 520, 540–41 (1993) (plurality

opinion); see also Fallon, 130 Harv. L. Rev. at 537.

13

II.

Preemption Should Not Turn On State

and Local Legislative Intent Beyond

the Statutory Text

The

Eighth

Circuit’s

approach—that

preemption under the PSA depends on inquiry into

state legislative motive—would raise numerous

conceptual and practical problems. It would also

implicate serious federalism concerns.

A.

Inquiring Into Extra-Textual

Legislative Intent Raises Serious

Conceptual Problems

It is doubtful that the concept of collective

intent—of the group of legislators and executivebranch officials who enacted the state legislation—is

intellectually coherent. As this Court stated, “[w]hat

motivates one legislator to vote for a statute is not

necessarily what motivates scores of others to enact

it.” Pacific Gas, 461 U.S. at 216 (citing O’Brien, 391

U.S. at 383–84); see 2 Joseph Story, Commentaries on

the Constitution of the United States 533 (Hilliard,

Gray & Co. 1833) (mindsets of individual legislators

might be “opposite to, or wholly independent of each

other”). There is no reason to expect consistency in

the disparate motives of different legislators for laws

that may themselves “further more than one aim.”

Shady Grove, 559 U.S. at 404. Thus, as Justice Scalia

wrote, looking for the purpose of a multimember body

is “almost always . . . impossible.”

Edwards v.

Aguillard, 482 U.S. 578, 636 (1987) (Scalia, J.,

dissenting); see also Kenneth A. Shepsle, Congress Is

a “They,” Not an “It”: Legislative Intent as Oxymoron,

12 Int’l Rev. L. & Econ. 239, 249 (1992) (it is “fruitless

to attribute intent to the product of [legislators’]

14

collective efforts”); Robert C. Farrell, Legislative

Purpose and Equal Protection’s Rationality Review,

37 Vill. L. Rev. 1, 11 (1992) (“If legislative purpose is

the mere aggregation of the motivations of individual

legislators, then there seems no escaping the

conclusion that the very idea of legislative purpose is

incoherent.”); John F. Manning, Textualism and

Legislative Intent, 91 Va. L. Rev. 419, 427–32 (2005);

Caleb Nelson, What Is Textualism?, 91 Va. L. Rev.

347, 353–57 (2005); Ronald Dworkin, Law’s Empire

321–33 (Harv. Univ. Press, 1986).

Even if collective intent were a coherent idea,

to go looking for it outside the well-marked

boundaries of statutory interpretation would raise a

slew of other difficult conceptual problems. See

Fallon, 130 Harv. L. Rev. at 537–41. What legal rules

determine how and when to ascribe an intention to a

particular legislator? What if a forbidden intention

existed but was not necessary to a legislator’s vote?

What percentage of legislators need to share a

forbidden intention for a law to be tainted? What if

the illicit intentions of some legislators drove them to

persuade others to vote for a bill on permissible

grounds—is that a sufficient causal link to bad

intent? And, for all of these questions, where should

courts look for answers? See Virginia Uranium, 587

U.S. at 776–77.

B.

Inquiring Into Extra-Textual

Legislative Intent Raises Serious

Practical Problems

The practical difficulties with discerning

collective intent are just as large as the conceptual

problems discussed above, and they are no less

15

crippling to the concrete judicial enterprise of

deciding cases.

1. A motive-based inquiry would produce

arbitrary outcomes. It is clear, as even the Eighth

Circuit acknowledges, that states retain the “power to

prescribe location or routing.” Couser v. Shelby Cnty.,

139 F.4th 664, 672 (8th Cir. 2025) (emphasis omitted).

Yet under the Eighth Circuit’s approach, Shady

Grove’s premonition has come to pass, in which “one

State’s statute could survive pre-emption . . . while

another State’s identical law would not, merely

because its authors had different aspirations.” 559

U.S. at 404. 5

Consider first the Fourth and Fifth Circuits,

which found that local pipeline setbacks were not

“safety standards” preempted by the PSA. See

Washington Gas Light Co. v. Prince George’s Cnty.

Council, 711 F.3d 412, 421–22 (4th Cir. 2013); Tex.

Midstream Gas Servs. v. City of Grand Prairie, 608

F.3d 200, 212 (5th Cir. 2010). Contrast that with the

Eighth Circuit’s decision finding nearly identical

setbacks as preempted given their safety-oriented

“purpose.” Couser, 139 F.4th at 670. The Eighth

Circuit “look[ed] beyond the [counties’ proffered]

rationale” and inferred that safety was their “primary

motivation” because (1) the “blanket application” of

the setbacks “to economically developed and remote

areas” undercut the proffered non-safety rationales

and (2) the setbacks “require[] larger setbacks from

5 In the context of federal legislation, this Court has similarly

“decline[d] to void . . . legislation which Congress had the

undoubted power to enact and which could be reenacted in its

exact form if the same or another legislator made a ‘wiser’ speech

about it.” O’Brien, 391 U.S. at 384.

16

buildings with vulnerable populations.” Id. at 671

(citation omitted). The court surmised that safety is

a “core,” rather than “incidental,” purpose of the

setbacks, and it thus deemed them preempted “safety

standards.” Id. (citation omitted).

In sum: According to the Eighth Circuit, if

safety is a municipality’s “primary motivation”

behind enacting a local pipeline setback, the setback

is preempted under the PSA. Another municipality’s

identical pipeline setback would survive if the court

finds that non-safety motivations played a bigger role

in the legislative process. It is simply immaterial to

the Eighth Circuit that the setbacks have the same

effect. Whatever Congress intended to preempt in the

PSA, it cannot have meant that.

2. Collective motive is extraordinarily difficult

for courts to discern. Even putting aside the

conceptual difficulties surrounding collective intent,

inquiry into the subjective motives of even a single

state official is usually “an unsatisfactory venture.”

Pacific Gas, 461 U.S. at 216. How will courts decide

with any confidence what state lawmakers were

thinking when they enacted the statute? What is the

relevance, if any, of unsuccessful efforts to repeal that

law that did not even come to a vote? Does the intent

of those subsequent legislators count? What about

the concerns of staffers, lobbyists, concerned citizens,

and other interest groups? What significance should

courts attach to legislators’ public statements to the

media on the “realities of the legislative bargaining?”

Edwards, 482 U.S. at 638 (Scalia, J., dissenting).

What about legislators’ private statements to friends?

Would a court consider “postenactment testimony

from legislators, obtained expressly for the lawsuit?”

Id. “All of these sources, of course, are eminently

17

manipulable. Legislative histories can be contrived

and sanitized, favorable media coverage orchestrated,

and postenactment recollections conveniently

distorted.” Id.

And if discerning federal legislative history

were not difficult enough, adoption of the Eighth

Circuit’s rule would require federal judges “to por[e]

through state legislative history—which may be less

easily obtained, less thorough, and less familiar than

its federal counterpart.” Shady Grove, 559 U.S. at

405 (citing Roy M. Mersky & Donald J. Dunn,

Fundamentals of Legal Research 233 (8th ed. 2002);

Jose R. Torres & Steve Windsor, State Legislative

Histories: A Select, Annotated Bibliography, 85 L. Lib.

J. 545, 547 (1993)); see also Virginia Uranium, 587

U.S. at 777 (“[H]ow are courts supposed to conduct a

reasonable inquiry into these questions when

recorded state legislative history materials are often

not as readily available or complete as their federal

counterparts?”). All of these questions—or, rather,

the fact that “there are no good answers,” Edwards,

482 U.S. at 638 (Scalia, J., dissenting)—explain why

the Court has generally avoided legislative-motive

inquiries, and why it should do so here. 6

For these reasons, scholars have argued that an improper

motive should never, standing alone, invalidate a state law. See

Laurence H. Tribe, The Mystery of Motive, Private and Public:

Some Notes Inspired by the Problems of Hate Crime and Animal

Sacrifice, 1993 Sup. Ct. Rev. 1, 23 (arguing that illicit legislative

motive should never be sufficient to invalidate laws regulating

conduct); Richard L. Hasen, Bad Legislative Intent, 2006 Wis. L.

Rev. 843, 846 (proof of bad intent “should be neither necessary

nor sufficient for an election law challenge to succeed”); Fallon,

6

18

C.

Inquiring Into Extra-Textual

Legislative Intent Raises Serious

Federalism Problems

Turning preemption on legislative motive

would also trample important state sovereignty

interests. “In preemption analysis,” courts assume

“that the historic police powers of the States are not

superseded unless that was the clear and manifest

purpose of Congress.” Arizona, 567 U.S. at 400

(internal quotation marks and citation omitted). An

inquiry into legislative motive would harm the very

state sovereignty interests that the presumption

against preemption aims to protect.

A preemption inquiry into state legislative

motives “is perilous . . . not just for the judges who will

very likely reach the wrong result, but also for the

legislators who find that they must assess the validity

of proposed legislation—and risk the condemnation of

having voted for an unconstitutional measure—not on

the basis of what the legislation contains, nor even on

the basis of what they themselves intend, but on the

basis of what . . . others have in mind.” Edwards, 482

U.S. at 638–39 (Scalia, J., dissenting). Judicial focus

on state legislative motives would also create

tremendous uncertainty about the power left to the

States. For this reason, Shady Grove stated that,

rather than reshaping text to a federal court’s

conception of purpose, “the state-friendly approach

[is] to accept the law as written.” 559 U.S. at 404

(emphasis added).

130 Harv. L. Rev. at 529 (“[C]ourts should never invalidate

legislation solely because of the subjective intentions of those

who enacted it.”).

19

Consider the questions that could daunt state

legislators here: How much concern for safety is too

much? Who has to express that concern and in what

contexts? If everyone who voted for a pipeline setback

had an independent, non-safety reason to pass it, has

the state acted within the federal sphere or not? And

is there any way to control whether a “location and

routing” ordinance runs into the federal field, when

one legislator with permissible motives cannot control

the motives or intentions of other legislators,

commentators, or officials?

The natural result of judicial inquiries into

state legislative motives will be to stifle debate.

Democracy benefits from debate on public issues that

is “uninhibited, robust, and wide-open.” New York

Times Co. v. Sullivan, 376 U.S. 254, 270 (1964). For

that reason, and in accordance with the longstanding

principle of legislative immunity, both the federal and

numerous state constitutions have Speech and

Debate Clauses to preclude judicial “question[ing]” of

legislators for statements made or votes cast in

legislative session. See U.S. Const. art. I, § 6, cl. 1; cf.

Smith v. Iowa Dist. Ct. for Polk Cnty., 3 N.W.3d 524,

527 (Iowa 2024) (holding that the Iowa Constitution

contains a similar “legislative privilege”). A central

purpose of these clauses is “to protect legislative

independence.” United States v. Gillock, 445 U.S.

360, 369 (1980). But a motive-driven preemption rule

would constrain state legislators in their

deliberations. They would have the incentive to

minimize public debate and to resort to secrecy and

subterfuge, rather than risk stepping into federal

territory by offering even tentative federal-fieldrelated justifications for a proposed law.

20

Under the PSA, states and municipalities

would be highly constrained in regulating the

“location and routing” of pipelines that Congress left

to their judgment. 49 U.S.C. § 60104(e). “[L]ocal land

use . . . ordinances are typically, and understandably,

driven by multiple concerns, including economic,

environmental, and safety.” See Couser, 139 F.4th at

677 (Kelly, J., concurring in part and dissenting in

part). It is thus extremely difficult to separate

permissible motives—like environmental and

economic concerns—from safety issues.

The

infringement on deliberative freedom about even

these traditional areas of state and local regulation

intrudes upon core state and local prerogatives.

Then there are the severe practical burdens of

responding to the judicial inquiry. Any responsible

method of aggregating individual motives into a

collective legislative intention would have to involve

testimony from at least a substantial number of the

legislators who voted for the law in question, likely

requiring the exact “questioning” that Speech and

Debate Clauses preclude. It would also require

testimony from the governor who signed the law,

possibly those legislators who voted against the law,

and any staffers, lobbyists, and commentators who

could provide context and give their own perceptions

of what legislators’ real motives were. One can

imagine few more intrusive ways for federal courts to

burden the daily operations of sovereign states.

And, it bears repeating, the entire invasive

inquiry may well be for naught. After reviewing all of

that testimony, documents from the time, lawmakers’

public and private statements, and the views of

commentators, staffers, and lobbyists, the court may

still be unable to discern any unified motive behind

21

the law, never mind a forbidden one. There is no

reason to burden state sovereignty in this way when

legislative motive is irrelevant to the Supremacy

Clause analysis that suffices in every other area,

when the inquiry is extremely unlikely to be

enlightening, and—last but not least—when

Congress still retains ample authority “to rethink the

division of regulatory authority in light of its possible

exercise by the States to undercut a federal objective.”

Pacific Gas, 461 U.S. at 223.

III.

The Pipeline Safety Act Does Not

Require A Motive Inquiry

Against all of that background about the

oddities and practical problems raised by legislativemotive inquiries, the PSA does not provide a reason

to embark on one.

As the Petitioners’ brief

persuasively explains, “[w]hen Congress has enacted

an express preemption clause, the preemption inquiry

begins and ends with the text” because “[t]he ‘plain

wording of the clause . . . necessarily contains the best

evidence of Congress’ pre-emptive intent.’” Pet. 19

(quoting CSX Transp., Inc. v. Easterwood, 507 U.S.

658, 664 (1993)).

The PSA expressly preempts “[a] State

authority” from “adopt[ing] or continu[ing] in force

safety standards for interstate pipeline facilities or

interstate pipeline transportation,” 49 U.S.C.

§ 60104(c) , but preserves the traditional authority of

local governments to “to prescribe the location or

routing of a pipeline facility,” id. § 60104(e). Arguably

a “non-preemption clause,” Virginia Uranium, 587

U.S. at 769, section 60104(e) is objective and does not

require a legislative-motive-driven inquiry into a

22

state or local government regulation to determine

whether a regulation “prescribe[s] the location or

routing of a pipeline facility.” § 60104(e); see CastroHuerta, 597 U.S. at 642 (“[T]he text of a law

controls . . . .”).

Contrast the PSA’s non-preemption clause

with statutes that limit or condition state or local

governments’ exercise of their traditional authority

based on their legislative motives. For example, to

“reduc[e] . . . the impediments imposed by local

governments on the installation of facilities for

wireless communications,” the Telecommunications

Act prohibits state and local governments from

“limit[ing] the placement of wireless facilities ‘on the

basis of the environmental effects of radio frequency

emissions.’” City of Rancho Palos Verdes v. Abrams,

544 U.S. 113, 115–16 (2005) (emphasis added)

(quoting 47 U.S.C. § 332(c)(7)(B)(iv)). And as noted

above, the Atomic Energy Act preserves state and

local governments’ traditional regulatory authority

only insofar as they “regulate activities for purposes

other than protection against radiation hazards.”

Virginia Uranium, 587 U.S. at 801 (Roberts, C.J.,

dissenting) (quoting 42 U.S.C. § 2021(k)). The PSA

contains no similar, motive-driven limits or

prerequisites to state and local governments’ exercise

of their traditional authority. 49 U.S.C. § 60104(e).

“[T]his Court may not narrow a provision’s reach by

inserting words Congress chose to omit,” and the

Eighth Circuit should not have done so here. Lomax,

140 S. Ct. at 1724; cf. Shady Grove, 559 U.S. at 403–

05.

23

CONCLUSION

The Petition for Writ of Certiorari should be

granted.

Respectfully submitted.

JONATHAN S. MASSEY

COUNSEL OF RECORD

CHISEUL KYLIE KIM

AUSTIN S. MARTIN

MASSEY & GAIL LLP

1000 Maine Ave. SW

Suite 450

Washington, D.C. 20024

(202) 652-4511

24