Amicus Curiae Brief — Kentucky, et al., Petitioners v. Environmental Protection Agency, et al.

Nos. 26-277 & 26-298

IN THE

Supreme Court of the United States

___________

KENTUCKY, et al.,

Petitioners,

v.

ENVIRONMENTAL PROTECTION AGENCY, et al.,

Respondents.

___________

CHAMBER OF COMMERCE OF THE UNITED STATES

OF AMERICA, et al.,

Petitioners,

v.

UNITED STATES ENVIRONMENTAL PROTECTION

AGENCY; LEE ZELDIN, ADMINISTRATOR, et al.,

Respondents.

___________

On Petitions for Writs of Certiorari to the

U.S. Court of Appeals for

the District of Columbia Circuit

___________

BRIEF OF THE HONORABLE ANDREW R. WHEELER

AND WASHINGTON LEGAL FOUNDATION AS

AMICI CURIAE SUPPORTING PETITIONERS

___________

CORY L. ANDREWS

Counsel of Record

WASHINGTON LEGAL FOUNDATION

2009 Massachusetts Ave., NW

Washington, DC 20036

(202) 588-0302

candrews@wlf.org

September 15, 2026

QUESTIONS PRESENTED

1. Whether the Environmental Protection

Agency (EPA) may revise a National Ambient Air

Quality Standard (NAAQS) without the “thorough

review” required by section 109(d)(1) of the Clean Air

Act simply because it acts “earlier or more frequently”

than mandated.

2. Whether EPA must consider costs and

attainability when exercising discretion to review and

revise a NAAQS “earlier or more frequently” than

mandated.

iii

TABLE OF CONTENTS

QUESTIONS PRESENTED ................................... ii

TABLE OF AUTHORITIES .................................. iv

INTERESTS OF AMICI CURIAE .......................... 1

INTRODUCTION & SUMMARY

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

ARGUMENT ........................................................... 5

I.

THE DECISION BELOW CREATES A ONE-WAY

RATCHET THAT CONGRESS NEVER ENACTED ...... 5

A. A public-health-only criterion cannot

discipline the decision to revise a nonthreshold standard ....................................... 5

B. Congress supplied the constraint the

criterion could not ........................................ 6

C. The decision below dismantles both

checks at once ............................................... 8

II. THE ASYMMETRY IS PROVEN IN THIS CASE,

AND NO ADMINISTRATION CAN READILY

UNDO IT ........................................................... 11

III. WAITING WILL NOT PRODUCE A BETTER

CASE—ONLY A MORE ENTRENCHED ERROR .... 13

CONCLUSION ...................................................... 16

iv

TABLE OF AUTHORITIES

Page(s)

CASES:

Am. Trucking Ass’ns v. EPA,

175 F.3d 1027 (D.C. Cir. 1999), aff’d in part,

rev’d in part sub nom. Whitman v. Am. Trucking

Ass’ns, 531 U.S. 457 (2001) ................................ 15

Dep’t of Homeland Sec. v. Regents of the Univ. of

Cal.,

591 U.S. 1 (2020)................................................. 12

Encino Motorcars, LLC v. Navarro,

579 U.S. 211 (2016)............................................. 12

FCC v. Fox Television Stations, Inc.,

556 U.S. 502 (2009)............................................. 12

Lead Indus. Ass’n v. EPA,

647 F.2d 1130 (D.C. Cir. 1980) ........................... 10

Loper Bright Enters. v. Raimondo,

603 U.S. 369 (2024)......................................... 2, 14

Michigan v. EPA,

576 U.S. 743 (2015)............................... 4, 9, 10, 15

Motor Vehicle Mfrs. Ass’n of the U.S., Inc. v. State

Farm Mut. Auto. Ins. Co.,

463 U.S. 29 (1983)............................................... 10

Murray Energy Corp. v. EPA,

936 F.3d 597 (D.C. Cir. 2019) ............................. 10

Util. Air Regul. Grp. v. EPA,

573 U.S. 302 (2014)............................................... 8

West Virginia v. EPA,

597 U.S. 697 (2022)............................................... 2

v

TABLE OF AUTHORITIES

(continued)

Page(s)

Whitman v. Am. Trucking Ass’ns,

531 U.S. 457 (2001)..................... 3–6, 9, 10, 14, 15

STATUTES:

42 U.S.C. § 7409(b)(1) .................. 3, 4, 8, 9, 10, 14, 15

42 U.S.C. § 7409(d)(1) .............................. 1, 3, 8, 9, 10

42 U.S.C. § 7409(d)(2)(B) ....................................... 3, 7

42 U.S.C. § 7502(e) ................................................... 12

42 U.S.C. § 7607(b)(1) .......................................... 4, 13

Pub. L. No. 91-604, 84 Stat. 1676 .............................. 7

Pub. L. No. 95-95, 91 Stat. 685 .................................. 7

REGULATIONS:

85 Fed. Reg. 82,684 (Dec. 18, 2020)..................... 1, 11

89 Fed. Reg. 16,202 (Mar. 6, 2024) .................. 4, 8, 11

OTHER AUTHORITIES:

Michael A. Livermore & Richard L. Revesz,

Rethinking Health-Based Environmental

Standards, 89 N.Y.U. L. Rev. 1184 (2014) .......... 6

1

INTERESTS OF AMICI CURIAE *

The Honorable Andrew R. Wheeler served as the

fifteenth Administrator of the United States

Environmental Protection Agency from 2019 to 2021,

following service as the agency’s Acting Administrator

and Deputy Administrator, and previously spent

nearly fifteen years in senior leadership roles for the

Senate Committee on Environment and Public Works,

including as its Staff Director and Chief Counsel. As

Administrator, he completed the most recent on-cycle

thorough review of the PM2.5 standard—the December

2020 review, informed by a full scientific assessment

and independent scientific advice, that retained the

standard which the off-cycle revision at issue here set

aside. See 85 Fed. Reg. 82,684 (Dec. 18, 2020). Having

exercised the revision judgment that § 7409(d)(1)

commits to the Administrator, he has a unique interest

in ensuring that the office’s statutory discretion—and

the completed reviews on which it rests—cannot be

displaced by a streamlined revision power that will

bind every future Administrator of either party.

Washington Legal Foundation is a nonprofit,

public-interest law firm and policy center with

supporters nationwide. WLF promotes free enterprise,

individual rights, limited government, and the rule of

law. It often appears as an amicus in disputes over the

structure and limits of the administrative state, to help

ensure that agencies exercise only the powers Congress

* No party’s counsel authored any part of this brief. No one,

other than WLF and its counsel, helped pay for the brief’s

preparation or submission. This brief’s filing more than ten days

before the due date constitutes timely notice to all parties of

Amici’s intent to file.

2

actually conferred. See, e.g., Loper Bright Enters. v.

Raimondo, 603 U.S. 369 (2024); West Virginia v. EPA,

597 U.S. 697 (2022).

Amici’s broader concern in this case is a practical

one. Businesses plan and build against regulatory

baselines, and no baseline reaches further than a

national ambient air quality standard. Planning

depends on stability, and stability depends on process.

A standard that can be reset at any time, on a partial

record, and, in practice, only in one direction is not a

baseline. It is a burden that can only grow.

Amici appear here because the decision below

creates a revision power no Congress enacted, beyond

the practical reach of any election, any administration,

and any court save this one. Those defects come at the

expense of the stability on which regulatory risk is

priced, capital is committed, and long-term projects are

built.

INTRODUCTION & SUMMARY OF ARGUMENT

Under the Clean Air Act, the Environmental

Protection Agency (EPA) sets a national limit on fineparticle air pollution. That limit operates as the

permitting baseline for virtually every major factory,

power plant, and industrial project in America. Unlike

any sector-specific rule, a national ambient air quality

standard (NAAQS) reaches economic activity of nearly

every kind. Congress wrote a two-way statute that

allows EPA to tighten or relax that standard, as

warranted. The court below effectively turned it into a

one-way ratchet.

3

Under the Act, a NAAQS “may be revised in the

same manner as promulgated.” 42 U.S.C. § 7409(b)(1).

Revised—not merely tightened. The power to revise

runs in both directions, and Congress disciplined it

with a single, carefully built procedure: every five

years, a “thorough review” of the air quality criteria—

the scientific record on which every standard rests—

and of the standards themselves, informed by an

independent

scientific

committee

whose

recommendations arrive roughly a year in advance.

§§ 7409(d)(1), (d)(2)(B). For nearly half a century, every

change to a NAAQS—and every decision to leave one

in place—passed through that gate.

The decision below removes the gate. It holds,

first, that EPA may revise a NAAQS off-cycle without

any thorough review. Ky. Pet. App. 25a. It holds,

second, that the Act prohibits EPA from considering

costs or consequences not only when setting a standard

but when deciding whether and when to revise one—at

“either stage.” Ky. Pet. App. 32a. On its own, each

holding is bad enough. Together they hand EPA a

power Congress never enacted: a one-way revision

power—perpetually

available,

procedurally

unencumbered, and pointed, in operation, only toward

ever-tighter standards. That is not statutory

interpretation. It is amendment. And only this Court

may undo it.

The direction comes from the only consideration

the panel’s reading now leaves in play. This Court has

described fine particulate matter as a “nonthreshold”

pollutant, one that “inflict[s] a continuum of adverse

health effects at any airborne concentration greater

than zero.” Whitman v. Am. Trucking Ass’ns, 531 U.S.

457, 475 (2001). A criterion limited to public health

4

thus always has more work to do. It supplies no obvious

stopping point—and no reason to wait. Every

permissible input invites another look downward.

That asymmetry is not hypothetical, and this

case proves it. Tightening the standard—lowering the

allowable concentration from 12.0 to 9.0 micrograms

per cubic meter (µg/m³)—proceeded on merely a partial

“supplement” to the existing science. 89 Fed. Reg.

16,202, 16,213 (Mar. 6, 2024). Undoing that revision—

as the agency itself, under new leadership, has urged—

requires everything the panel excused: a full

rulemaking, run through a criterion that, on the

panel’s reading, forbids the agency to weigh a single

consequence of its choice.

Whitman held that when EPA sets the level of a

standard, § 7409(b)(1)’s express command—“requisite

to protect the public health”—displaces cost. But this

Court has called that holding a “modest principle,” tied

to an express statutory directive, Michigan v. EPA, 576

U.S. 743, 755–56 (2015), and the panel stretched it

across a question Whitman never faced: the

antecedent, discretionary decision to reopen a settled

standard mid-cycle. At that threshold Michigan, not

Whitman, supplies the rule. The panel applied

Whitman anyway.

No further percolation is possible. Challenges to

NAAQS rules lie exclusively in the D.C. Circuit—the

court that decided this case. 42 U.S.C. § 7607(b)(1). No

other circuit will ever weigh in; no disagreement will

ever ripen; and because the asymmetry is structural,

every future case will arrive in precisely this posture—

a standard tightened without thorough review, already

reshaping conduct by the time any challenge is heard.

5

The ratchet binds every administration going forward

in mirror image: any administration may turn it

tighter; none may turn it back on the same terms. The

Court should grant the petitions.

ARGUMENT

I. THE DECISION BELOW CREATES A ONE-WAY

RATCHET THAT CONGRESS NEVER ENACTED.

The panel announced its two holdings in

separate sections of its opinion, addressing each in

isolation. Each is reason enough for review. The first

strips the structural check on off-cycle revision. The

second forbids the only substantive consideration that

could ever counsel restraint. Together they are

intolerable. What remains is a power found nowhere in

the statute—revision on demand, cabined only by a

criterion with no obvious stopping point of its own. And

as applied, its answer has only one direction: tighter.

A. A public-health-only criterion cannot

discipline the decision to revise a nonthreshold standard.

Start with Whitman’s own premise. Whitman

treated ozone and particulate matter as “‘nonthreshold’

pollutants that inflict a continuum of adverse health

effects at any airborne concentration greater than

zero,” thus requiring EPA “to make judgments of

degree.” 531 U.S. at 475. But if that is so, then below

any current standard there is always some incremental

health benefit to be claimed.

Scholars across the spectrum have diagnosed

the structural consequence. Because many pollutants

6

“lack ambient concentrations below which there is no

risk” of harm, a health-only criterion faces a “stoppingpoint problem”: “when costs cannot be considered, it is

difficult to justify any stopping point other than zero,”

for “if the only cognizable goal is to protect public

health, how can EPA justify a nonzero concentration?”

Michael A. Livermore & Richard L. Revesz, Rethinking

Health-Based Environmental Standards, 89 N.Y.U. L.

Rev. 1184, 1186–87 (2014).

Whatever one makes of the scholars’

prescriptions, their diagnosis holds: a criterion with no

built-in stopping point can set a level only by an act of

judgment—but by itself it can never explain restraint.

It cannot tell the Administrator that now is not the

time, that the science has not moved enough, that a

months-old judgment deserves repose.

Whitman glossed “requisite” as “not lower or

higher than is necessary,” 531 U.S. at 475–76, and in

principle that cuts both ways. But for a pollutant whose

air quality criteria, as this Court described them, posit

harm at every concentration, only one side of the ledger

ever has evidence. Measured solely by public health,

every existing standard can always be portrayed as

inadequate, and every moment as the right moment to

tighten. A criterion that always points the same way is

not a constraint on the timing of revision. It is an

accelerant.

B. Congress supplied

criterion could not.

the

constraint

the

Congress understood the problem, and its

solution was structural. From the start, the Act

contemplated revision—standards “may be revised in

7

the same manner as promulgated.” Pub. L. No. 91-604,

§ 4(a), 84 Stat. 1676, 1679–80. And in 1977, Congress

disciplined the practice by requiring a “thorough

review” of the criteria and standards at five-year

intervals, Pub. L. No. 95-95, § 106(a), 91 Stat. 685, 691,

paced by an independent scientific committee whose

own

quinquennial

review

must

reach

the

Administrator roughly a year before his deadline, 42

U.S.C. § 7409(d)(2)(B). The decision below called the

thorough-review requirement “an action-forcing

device” ensuring that standards “do not fall too far

behind the evolving scientific evidence.” Ky. Pet. App.

20a.

But the device forces action in both directions—

and that is the point. A comprehensive review of all the

criteria and all the standards, on a fixed clock, with the

full scientific record assembled first, is exactly the kind

of process that can justify restraint as well as change.

It is the only feature of the statute that can. And it is

how the statute operated in practice: until 2024, no

revision had ever issued without a completed thorough

review. See Chamber Pet. 16.

The state petitioners pressed that history below.

The revision, they charged, was “unprecedented” and

made “without regard for the reliance interests of those

affected by the revised standard.” Ky. Pet. App. 34a.

The panel below did not deny the novelty. Its answer

was authority alone. Congress, it held, permits revision

outside the five-year cycle “in the interests of public

health.” Ky. Pet. App. 34a.

The 2024 Final Rule thus stands as the first of

its kind. It “partially reopen[ed]” the criteria and

deferred the full assessment of new studies “for the

8

next PM NAAQS review.” 89 Fed. Reg. at 16,213. When

an agency discovers, five decades on, a streamlined

path around its own governing procedure, some

skepticism is in order. Cf. Util. Air Regul. Grp. v. EPA,

573 U.S. 302, 324 (2014). The long silence is itself

evidence that something is awry. Administration after

administration, whatever its regulatory ambitions,

treated thorough review as the price of revision. The

better explanation is not that all of them somehow

missed the streamlined path, but that the statute

simply does not provide one.

C. The decision below dismantles both checks

at once.

The panel’s decision removes the structural

check. EPA claimed the off-cycle power under the

second sentence of § 7409(d)(1): the Administrator

“may review and revise criteria or promulgate new

standards earlier or more frequently than required

under this paragraph.” See Chamber Pet. 16–17.

However the panel reached its result, the holding is

that the Administrator may revise a NAAQS “more

frequently without completing a ‘thorough review,’”

Ky. Pet. App. 25a—and it is undisputed that no

thorough review preceded this revision, Ky. Pet. App.

19a.

But the sentence Congress wrote still says

“review,” and on the panel’s reading nothing in the Act

prescribes its depth. The panel called its interpretation

“not toothless,” pointing to § 7409(b)’s substantive

standard and the general “requirement of reasoned

decisionmaking.” Ky. Pet. App. 25a. But the

substantive standard is the criterion with no stopping

point, and reasoned decisionmaking is administrative

9

law’s floor, not Congress’s design. This case has already

measured that floor: a partial “supplement” sufficed.

The decision forecloses the only substantive

check: consideration of cost. The panel held that

“[w]hether the Administrator considers costs and

attainability when deciding whether to revise a

NAAQS or when setting the NAAQS would have the

same impermissible effect,” and that nothing would

“permit the Administrator to consider costs at either

stage.” Ky. Pet. App. 31a–32a. The panel thus held not

merely that EPA need not consider costs at the

threshold, but that it may not.

That reading extends Whitman far beyond its

rationale. Whitman rested on an express statutory

command: § 7409(b)(1) “unambiguously bars cost

considerations from the NAAQS-setting process.” 531

U.S. at 471 (emphasis added). This Court has since

confined Whitman to exactly that footing—a “modest

principle” applicable “where the Clean Air Act

expressly directs EPA to regulate on the basis of a

factor that on its face does not include cost.” Michigan,

576 U.S. at 755–56.

No

comparable

command governs the

antecedent question confronted here—whether to

undertake a discretionary off-cycle revision. That

decision arises under the second sentence of

§ 7409(d)(1), which contains no public-health-only

limitation—only a permissive “may.” For that kind of

threshold judgment, Michigan, not Whitman, supplies

the frame: absent an express statutory bar, cost is not

forbidden to an agency deciding whether to act—it is

ordinarily part of the “reasoned decisionmaking” that

agencies must engage in. Id. at 750. Agencies have long

10

treated cost as “a centrally relevant factor when

deciding whether to regulate,” id. at 752–53 (emphasis

added). Michigan therefore refused to read the

statutory trigger “as an invitation to ignore cost.” Id. at

753.

Yet the appeals court converted that narrow,

text-bound preclusion into a roving prohibition,

forbidding cost—the one consideration capable of

counseling restraint—at every stage of the revision

decision. The conversion is the panel’s alone, not

Whitman’s: Whitman found an express bar in

§ 7409(b)(1) and enforced it there; the second sentence

of § 7409(d)(1) contains no counterpart. The panel

invented one.

Murray Energy Corp. v. EPA, 936 F.3d 597 (D.C.

Cir. 2019), does not bridge the gap. It construed

“appropriate” in the first sentence of § 7409(d)(1)—the

mandatory quinquennial review, where a completed

thorough review and the § 7409(b) criterion do the

substantive work—and said nothing about the second

sentence’s discretionary trigger. Id. at 605, 622–23.

And the rule of Lead Indus. Ass’n v. EPA, 647 F.2d

1130, 1150 (D.C. Cir. 1980)—that an agency may not

take account of factors Congress excluded—

presupposes the exclusion, which is the very question

here. Neither case decided that when EPA volunteers

to reopen a standard early, it must blind itself to every

consequence of doing so. And this Court’s own version

of the excluded-factors rule—agency action is arbitrary

when it rests “on factors which Congress has not

intended it to consider,” Motor Vehicle Mfrs. Ass’n of

the U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 463

U.S. 29, 43 (1983)—asks the same question the panel

skipped: what did Congress intend?

11

Strip away the thorough review, forbid the

weighing of cost, and the result is a power that may be

exercised at any time, on a self-selected partial record,

and that—for a non-threshold pollutant—has pointed

only down. Either holding, standing alone, would

warrant this Court’s attention. In combination they

demand it. Whether the Act contains such a power is a

question the court below has now answered for the

Nation, and only this Court can answer it correctly.

II.

THE ASYMMETRY IS PROVEN IN THIS CASE, AND

NO ADMINISTRATION CAN READILY UNDO IT.

The Court need not take this asymmetric

structure on faith. The ratchet has already turned

once, in this very case. In December 2020, at the close

of a completed review, the agency retained the 12.0

standard “without revision.” 85 Fed. Reg. 82,684 (Dec.

18, 2020). Only six months later, it announced its

reconsideration of that decision. 89 Fed. Reg. at 16,210.

It issued a partial “supplement” to the existing 2019

science assessment in May 2022, id. at 16,213, then

finalized a tightening from 12.0 to 9.0 µg/m³ by March

2024, id. at 16,202, 16,204. The entire revision ran on

a partially reopened record, with the balance of the new

science deferred to the next full review. Id. at 16,213.

Under the logic of the decision below, all of that was

lawful precisely because no thorough review was

required—and none was performed.

Going back up is another matter. After a change

in administrations, the agency concluded that the 2024

rule was unlawful and moved to vacate it. The appeals

court denied the motion and upheld the rule on the

merits. Ky. Pet. App. 8a. That standard now binds. The

only remaining path to revisit it is a new rulemaking.

12

And that rulemaking must answer for the “serious

reliance interests” the existing rule has engendered.

FCC v. Fox Television Stations, Inc., 556 U.S. 502, 515

(2009); see Dep’t of Homeland Sec. v. Regents of the

Univ. of Cal., 591 U.S. 1, 30 (2020). It must supply the

“reasoned explanation” any change of course demands.

Encino Motorcars, LLC v. Navarro, 579 U.S. 211, 222

(2016).

Reliance, in other words, now cuts almost

entirely one way: it could not stop the standard’s

tightening, Ky. Pet. App. 34a, but it will weigh heavily

against any loosening. Reliance, moreover, is not the

only one-way force. The Act’s own anti-backsliding

provision, § 7502(e), can hinder any future relaxation,

and the implementation clock is already running—a

district court has ordered EPA to complete final area

designations under the new standard by February

2027. See 42 U.S.C. § 7502(e); Chamber Pet. 7.

And under the appeals court’s second holding,

that rulemaking must be conducted with the agency’s

eyes closed. Consideration of costs, attainability, or

disruption is forbidden “at either stage.” Ky. Pet. App.

32a. The sole permissible criterion is one that, for a

non-threshold pollutant, registers only reasons to go

lower. Tightening demanded nothing beyond that

partial supplement. Loosening will require the full

rulemaking the agency bypassed—and even then, the

only criterion the agency may consult is one that offers

no ready reason ever to loosen.

This is not a grievance about any particular

administration. The values this Court has enforced in

its change-of-position cases—Fox, Encino, Regents—

13

are symmetry values: the same rules of reasoned

transition apply whichever way policy moves.

The decision below writes asymmetry into the

statute itself. An administration inclined to tighten

may do so at will, on a record of its own choosing, and

without weighing a single consequence. An

administration inclined to reconsider inherits a fulldress rulemaking governed by a criterion that burdens

its project from the start. Whatever one thinks of any

given standard, no Congress enacted that scheme. The

asymmetry is not one the political branches can cure—

each administration simply inherits it in turn, as this

case has already shown. Restoring the statute

Congress wrote is work only this Court can do.

III.

WAITING WILL NOT PRODUCE A BETTER

CASE—ONLY A MORE ENTRENCHED ERROR.

Ordinarily the Court can let a question mature.

Not this one. Congress channeled every challenge to a

NAAQS rule into the D.C. Circuit alone. 42 U.S.C.

§ 7607(b)(1). The decision below is therefore the

national rule today, and it will be the national rule in

every future case. No other court of appeals can ever

disagree with it, much less dislodge it, and under the

law of the circuit, the published holding will govern

each successive revision until this Court intervenes.

Congress kept for itself the power to amend the Act; for

now, the panel’s amendment controls instead.

Percolation is not merely unlikely; the ratchet

forecloses it. Because the power effectively runs only

one way, every future vehicle will look exactly like this

one—a standard tightened off-cycle without thorough

review, with designations, implementation plans, and

14

permitting consequences accumulating while any

challenge winds through the exclusive forum, with the

decision below as the binding precedent. Waiting for a

better vehicle means waiting for this same vehicle—

only arriving later, with more of those harmful

consequences locked in. See Chamber Pet. 42–43.

And nothing confines the power to one use: each

future administration inclined to tighten can turn the

ratchet again (and again) on the same truncated basis,

while

the

attainment

and

implementation

framework—built on the premise of standards stable

enough to plan against—absorbs revision after

revision. Nor is the delay free—a revised NAAQS

begins reordering primary conduct long before judicial

review concludes (new projects must model their

emissions against it from the standard’s effective date,

see Chamber Pet. 11), so each round of waiting

entrenches the panel’s reading a little further.

The question is as clean here as it will ever be.

Both holdings were squarely presented, fully litigated

through a change in administrations, and decided in a

published opinion construing the statute de novo under

Loper Bright. Ky. Pet. App. 36a (citing 603 U.S. at 412–

13). There is no vehicle problem to wait out, no

conflicting authority to wait for, and no factual dispute

in the way. There is only the choice between answering

the question now and answering it after the ratchet has

turned yet again. Delay will not improve the question;

it will only raise the price of answering it.

* * *

There is one more reason not to wait. Whitman

upheld § 7409(b)(1) against a nondelegation attack

because the discretion it confers is “well within the

15

outer limits of our nondelegation precedents.” 531 U.S.

at 474. But the delegation the Court measured sat

inside a statute of mandatory comprehensive review,

independent scientific advice on a fixed schedule, and

revision “in the same manner as promulgated.”

§ 7409(b)(1).

The panel’s reading subtracts the structure and

keeps only the criterion—a criterion the court of

appeals once described as leaving the agency “free to

pick any point between zero and a hair below the

concentrations yielding London’s Killer Fog.” Am.

Trucking Ass’ns v. EPA, 175 F.3d 1027, 1037 (D.C. Cir.

1999), aff’d in part, rev’d in part sub nom. Whitman v.

Am. Trucking Ass’ns, 531 U.S. 457 (2001). A

standardless power to reset the nation’s air-quality

baseline at any time, on a partial record, with

consequences excluded from consideration by law,

presses on the constitutional limits Whitman found

comfortably satisfied.

The Court need not go near those limits to decide

this case, and Amici do not ask it to. Between two

readings of a statute—one that raises grave

constitutional doubt, one that does not—the choice

ordinarily makes itself. The panel chose the first,

leaving the criterion alone while erasing both checks.

The petitions supply the second: the 1977 thoroughreview requirement, enforced as Congress wrote it, and

Whitman as the modest, standard-setting principle

that Michigan already confirmed. That choice asks

nothing novel of this Court and keeps the statute where

Whitman left it. It is the appeals court’s interpretation,

not the petitioners’, that manufactures constitutional

doubt. Granting review—and restoring the statute’s

own limits—is the avoidance.

16

CONCLUSION

The Court should grant both petitions.

Respectfully submitted,

September 15, 2026

CORY L. ANDREWS

Counsel of Record

WASHINGTON LEGAL

FOUNDATION

2009 Mass. Ave., NW

Washington, DC 20036

(202) 588-0302

candrews@wlf.org