Amicus Curiae Brief — Amber Lavigne, Petitioner v. Great Salt Bay Community School Board

No. 25-759

In the Supreme Court of the United States

__________

AMBER LAVIGNE,

v.

Petitioner,

GREAT SALT BAY COMMUNITY SCHOOL BOARD,

Respondent.

__________

On Petition for a Writ of Certiorari to the

United States Court of Appeals for the First Circuit

__________

BRIEF OF THE MANHATTAN INSTITUTE

AS AMICUS CURIAE

IN SUPPORT OF PETITIONER

__________

Ilya Shapiro

Counsel of Record

Trevor Burrus

MANHATTAN INSTITUTE

52 Vanderbilt Ave.

New York, NY 10017

(212) 599-7000

ishapiro@manhattan.institute

February 23, 2026

i

QUESTION PRESENTED

This brief focuses on the first question presented in

the petition:

Whether a court can rely on a probable alternative

explanation at the 12(b)(6) stage to dismiss a claim, as

five circuits hold, or whether a complaint can only be

dismissed if the plaintiff’s explanation is itself

implausible, as three circuits hold.

ii

TABLE OF CONTENTS

QUESTION PRESENTED ........................................... i

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

INTEREST OF AMICUS CURIAE ............................. 1

SUMMARY OF ARGUMENT ..................................... 1

ARGUMENT ................................................................ 4

I. THIS COURT HAS REPEATEDLY HELD

THAT “PLAUSIBILITY” IS NOT A

PROBABILITY REQUIREMENT AND

DOES NOT AUTHORIZE COURTS TO

WEIGH COMPETING INFERENCES ............ 4

II. THE CIRCUITS ARE INTRACTABLY

DIVIDED ON WHETHER A PLAINTIFF

MUST DISPROVE “OBVIOUS

ALTERNATIVE EXPLANATIONS” AT

THE PLEADING STAGE ................................. 7

A. Several Circuits Routinely and

Erroneously Dismiss Claims by

Crediting Defendants’ Asserted

“Innocent” Explanations as More

Likely ........................................................... 7

B. Five Circuits Correctly Hold That Rule

12(b)(6) Does Not Permit Courts to

Choose Between Two Plausible

Inferences ................................................... 10

III.THE PRACTICE OF WEIGHING

COMPETING EXPLANATIONS AT THE

PLEADING STAGE EXCEEDS

JUDICIAL COMPETENCE AND

DISPLACES THE STRUCTURAL ROLE

OF DISCOVERY AND FACT-FINDING ....... 13

iii

A. Crediting Facially Lawful Explanations

at the Pleading Stage Collapses the

Distinction Between Pleading,

Discovery, and Fact-Finding ..................... 13

B. Requiring Plaintiffs to Negate Benign

Explanations Before Discovery

Magnifies Information Asymmetry

and Undermines Uniform Federal

Procedure ................................................... 15

IV. THE DECISION BELOW PRESENTS A

CLEAN VEHICLE FOR RESOLVING

WHETHER COURTS MAY CREDIT

FACIALLY LAWFUL ALTERNATIVE

EXPLANATIONS AT THE PLEADING

STAGE ............................................................. 17

CONCLUSION .......................................................... 18

iv

TABLE OF AUTHORITIES

Page(s)

Cases

Anderson News, L.L.C. v. American Media,

Inc., 680 F.3d 162 (2d Cir. 2012) ........................... 10

Ashcroft v. Iqbal, 556 U.S. 662 (2009) ........................ 6

Bell Atl. Corp. v. Twombly,

550 U.S. 544 (2007) .............................................. 2, 5

Braden v. Wal-Mart Stores, Inc.,

588 F.3d 585 (8th Cir. 2009) .................................. 12

Doe v. Emory Univ.,

110 F.4th 1254 (11th Cir. 2024) .............................. 8

Evergreen Partnering Group, Inc. v. Pactiv

Corp., 720 F.3d 33 (1st Cir. 2013) ........................... 8

Frith v. Whole Foods Market, Inc.,

38 F.4th 263 (1st Cir. 2022) ..................................... 8

Hughes v. Northwestern Univ.,

63 F.4th 615 (7th Cir. 2023). ................................. 12

In re Pre-Filled Propane Tank Antitrust

Litigation, 860 F.3d 1059 (8th Cir. 2017).............. 13

Mator v. Wesco Distrib., Inc.,

102 F.4th 172 (3d Cir. 2024) .................................... 8

Matrixx Initiatives, Inc. v. Siracusano,

563 U.S. 27 (2011) .................................................... 6

McCleary-Evans v. Maryland Dept. of

Transp., 780 F.3d 582 (4th Cir. 2015) ..................... 9

Monell v. Dept. of Social Servs.,

436 U.S. 658 (1978) .................................................. 3

v

National Rifle Association v. Vullo,

602 U.S. 175 (2024) .......................................... 3, 6, 7

Palin v. N.Y. Times Co.,

940 F.3d 804 (2d Cir. 2019) ................................... 11

Pickett v. Texas Tech Univ. Health Sciences

Ctr., 37 F.4th 1013 (5th Cir. 2022) .......................... 9

Starr v. Baca, 652 F.3d 1202 (9th Cir. 2011)............ 11

Troxel v. Granville, 530 U.S. 57 (2000). ...................... 2

U.S. ex rel. Integra Med Analytics, L.L.C. v.

Baylor Scott & White Health,

816 F. App’x 892 (5th Cir. 2020).............................. 9

VoteVets Action Fund v. Dept. of Veterans

Affairs, 992 F.3d 1097 (D.C. Cir. 2021). ................ 11

Other Authorities

A. Benjamin Spencer, Plausibility Pleading,

50 B.C. L. Rev. 431 (2009) ..................................... 14

Alexander A. Reinert, The Burdens of

Pleading, 162 U. Pa. L. Rev. 1767 (2014).............. 17

Arthur R. Miller, From Conley to Twombly to

Iqbal, 60 Duke L.J. 1 (2010) .................................. 14

1

INTEREST OF AMICUS CURIAE 1

The Manhattan Institute (MI) is a nonprofit public

policy research foundation whose mission is to develop

and disseminate new ideas that foster greater economic choice and individual responsibility.

MI has filed numerous briefs in this Court and

other courts on the issues of parental rights and the

gender-transitioning of children. MI is concerned

about the scientific, policy, and constitutional issues

around such questions. But this brief focuses on the

procedural issue that must be considered before the

substantive issues. The question presented here affects a wide range of constitutional issues that MI has

an interest in, such as the right to earn a living, free

speech, racial discrimination, and property rights.

SUMMARY OF ARGUMENT

This case presents a recurring and outcome-determinative question about the proper application of Federal Rule of Civil Procedure 12(b)(6): whether courts

may dismiss a complaint by resolving factual ambiguity in favor of a defendant’s asserted “obvious alternative explanation,” or whether courts should accept

well-pleaded allegations as true and draw reasonable

inferences in the plaintiff’s favor.

This case’s underlying substantive issue, concerning the possible “social transitioning” of a minor by

school officials without parental notice or authorization, is undoubtedly important—and one that is

1 Rule 37 statement: All parties were timely notified of the

filing of this brief. No part of this brief was authored by any

party’s counsel, and no person or entity other than amicus funded

its preparation or submission.

2

increasingly before federal courts. Yet that issue is difficult to judicially review before addressing how and

why this case was dismissed. Here, amicus focuses on

the procedural question while still being concerned

about the substantive question of constitutionally

guaranteed parental rights, which is the oldest right

to be recognized as “fundamental” by this Court.

Troxel v. Granville, 530 U.S. 57, 65 (2000).

This Court has repeatedly held that plausibility

pleading is not a probability requirement. Bell Atl.

Corp. v. Twombly, 550 U.S. 544, 556 (2007). A complaint need not show that unlawful conduct is more

likely than lawful conduct; it need only allege sufficient factual matter to permit a reasonable inference

of liability. Despite that guidance, lower courts have

increasingly transformed Twombly’s reference to “obvious alternative explanations” into a dispositive

screening device—one that requires plaintiffs to negate lawful explanations before discovery and invites

courts to weigh competing inferences at the pleading

stage. In Twombly, the Court invoked “obvious alternative explanations” to describe circumstances in

which the pleaded facts themselves fail to support a

reasonable inference of liability, not to authorize

courts to choose between competing plausible accounts

of the same conduct at the pleading stage. Id. at 567.

That practice has produced an entrenched circuit

split. Some circuits dismiss complaints whenever alleged conduct is “consistent with” lawful behavior, effectively resolving factual uncertainty against plaintiffs. Other circuits correctly hold that Rule 12(b)(6)

does not permit courts to choose between two plausible

explanations for the same conduct, even if one appears

more likely at the outset. In those jurisdictions,

3

competing narratives are tested through discovery and

resolved by factfinders, not by judicial supposition.

The decision below squarely implicates this divide.

The First Circuit did not foreclose petitioner’s allegations that the school covertly “socially transitioned”

her child. Instead, it dismissed the complaint at the

pleading stage by crediting the school board’s asserted

alternative explanation, namely, that its officials were

merely interpreting state law rather than acting under

an unwritten policy of deception. App. 18a–20a. The

lower court regarded that explanation as dispositive in

assessing plausibility and invoked “common sense” to

weigh competing inferences without evidentiary development. Thus, the decision below aligned itself with

one side of the circuit split and is in tension with the

settled rule that plausible factual allegations must be

viewed in the light most favorable to the plaintiff.

This reasoning in the First Circuit’s decision reflects a broader and recurring phenomenon: the use of

facially lawful alternative explanations to defeat plausibility at the threshold, which affects innumerable

cases of all types. But, as this Court recently recognized in National Rifle Association v. Vullo, a government defendant’s claim that its actions were merely

“reasonable regulatory” conduct cannot be credited at

the pleading stage without displacing the role of discovery. 602 U.S. 175, 191 (2024). The same concern

arises in supervisory and Monell liability cases, where

defendants invoke internal processes or statutory compliance to rebut plausible allegations of knowledge,

ratification, or intent. See Monell v. Dept. of Social

Servs., 436 U.S. 658 (1978).

In particular, it is difficult to imagine how Monell

liability could be adequately alleged under such a test,

4

making this approach to 12(b)(6) pleading especially

destabilizing in public law and civil rights cases. In

such cases, evidence of intent, ratification, or institutional motive resides almost entirely within a defendant’s internal processes. Plaintiffs should not have to

disprove benign explanations that they don’t have the

information to disprove. Such a requirement turns

12(b)(6) into an illegitimate gatekeeping device based

on which circuit the case is filed in.

This case is a clean vehicle for resolving the circuit

split on whether Rule 12(b)(6) permits courts to resolve

factual ambiguity by choosing among competing explanations. The petition should be granted.

ARGUMENT

I. THIS COURT HAS REPEATEDLY HELD

THAT “PLAUSIBILITY” IS NOT A PROBABILITY REQUIREMENT AND DOES NOT AUTHORIZE COURTS TO WEIGH COMPETING

INFERENCES

This Court’s pleading decisions draw a clear and

consistent distinction between assessing whether a

complaint states a plausible claim for relief versus determining which of several competing explanations for

alleged conduct is more likely true. Rule 12(b)(6) permits the former; it does not authorize the latter.

Plausibility and probability may be somewhat necessarily vague terms, but they have enough meaning

in both common language and this Court’s precedents

to identify a clear distinction. If a wife notices her husband is charging unexpected hotel stays, taking late

nights at work, and is emotionally detached, she could

say it is “plausible” that he is cheating on her. If a

friend comes in with an alternative explanation,

5

perhaps that he’s working late to pursue a promotion,

it would be odd to describe that alternative explanation as “probable” without further evidence. It would

be even odder to say that the alternative explanation

defeats the plausibility of the original allegation. That

common usage follows this Court’s precedents.

In Bell Atlantic Corp. v. Twombly, the Court made

explicit that plausibility pleading “does not impose a

probability requirement at the pleading stage.” 550

U.S. at 556. A complaint survives dismissal so long as

the alleged facts permit the court to draw a reasonable

inference that the defendant is liable for the misconduct alleged. Id. at 556–57. The Court explained that

dismissal is warranted only where allegations are

“merely consistent with” liability and fail to cross the

line “between possibility and plausibility.” Id. at 557.

The presence of alternative lawful explanations does

not justify dismissal where the pleaded facts, taken as

true, reasonably support the plaintiff’s inference of liability. Id. at 556.

To be sure, Twombly recognized that an “obvious

alternative explanation” may reveal that the pleaded

facts themselves do not reasonably support the alleged

inference of illegality. Id. at 567. But Twombly does

not authorize courts to dismiss where the complaint

supports a reasonable inference of liability and the defendant merely offers a competing account of the same

conduct. The relevant question is whether the pleaded

facts render the plaintiff’s theory implausible, not

whether a defendant can articulate an alternative narrative consistent with lawful behavior.

That distinction is foundational. The Federal Rules

do not require plaintiffs to anticipate and negate every

conceivable innocent explanation for a defendant’s

6

conduct before discovery. Instead, courts must accept

well-pleaded factual allegations as true and draw reasonable inferences in the plaintiff’s favor. See Ashcroft

v. Iqbal, 556 U.S. 662, 678–79 (2009). Determining

which competing explanation ultimately prevails is

the function of discovery and fact-finding, not pleading-stage adjudication.

The Court also applied Twombly’s plausibility

framework in Matrixx Initiatives, Inc. v. Siracusano,

rejecting a categorical rule that allegations are insufficient absent “statistically significant” proof. 563 U.S.

27, 38–45 (2011). The Court held that materiality cannot be reduced to a bright-line statistical-significance

requirement and instead turns on the “source, content,

and context” of the information. Id. at 44–45. And

when Matrixx argued that researchers had not adequately ruled out an alternative cause (the common

cold), the Court answered in expressly pleading-stage

terms: “to survive a motion to dismiss, [plaintiffs] need

only allege ‘enough facts to state a claim to relief that

is plausible on its face.’” Id. at 52 n.12 (quoting

Twombly, 550 U.S. at 570 (2007)).

Most recently, this Court’s decision in National Rifle Association v. Vullo confirms that, at the Rule

12(b)(6) stage, courts may not dismiss a complaint by

crediting a defendant’s asserted lawful explanation

where the pleaded facts, taken as true and assessed as

a whole, plausibly support an inference of unlawful

conduct. 602 U.S. 175, 191–95 (2024). There, this

Court rejected the Second Circuit’s reliance on the regulator’s characterization of her actions as ordinary or

legitimate enforcement activity, reiterating that

courts must accept well-pleaded factual allegations as

true, draw reasonable inferences in the plaintiff’s

7

favor, and evaluate the complaint holistically rather

than allegation by allegation. Id. at 191–94. Although

discovery might later show that the defendant’s explanation is correct, the Court emphasized that such competing explanations cannot defeat plausibility at the

pleading stage when the complaint plausibly alleges

unconstitutional conduct. Id. at 195.

Taken together, these decisions establish a settled

rule: plausibility pleading is a threshold inquiry into

legal sufficiency, not a comparative assessment of factual likelihoods. An asserted “innocent” explanation

defeats a complaint only when it renders the plaintiff’s

inference implausible, not when it merely presents an

alternative account that might later persuade a factfinder. When courts dismiss claims by weighing competing inferences, they depart from this Court’s pleading framework and convert Rule 12(b)(6) into a mechanism for resolving factual disputes.

II. THE CIRCUITS ARE INTRACTABLY DIVIDED ON WHETHER A PLAINTIFF MUST

DISPROVE “OBVIOUS ALTERNATIVE EXPLANATIONS” AT THE PLEADING STAGE

A. Several Circuits Routinely and Erroneously Dismiss Claims by Crediting Defendants’ Asserted “Innocent” Explanations as

More Likely

Courts in the First, Third, Fourth, Fifth, and Eleventh Circuits have dismissed complaints when the alleged facts are “consistent with” lawful conduct, effectively requiring plaintiffs to negate defendants’ benign

explanations in the complaint itself. See, e.g., Frith v.

Whole Foods Market, Inc., 38 F.4th 263, 271–76 (1st

Cir. 2022) (affirming dismissal where the alleged facts

8

were “just as much in line with” a nondiscriminatory

explanation and therefore failed to plausibly allege

discriminatory intent). 2 Applying this approach, the

court below concluded that a complaint does not cross

the plausibility threshold where the pleaded facts support an “obvious alternative explanation” and do not

include allegations pointing meaningfully away from

lawful conduct.

That approach sits in tension with the First Circuit’s own prior instruction. As it explained in Evergreen Partnering Group, Inc. v. Pactiv Corp., at the

pleading stage courts may not choose between “competing inferences” or “credit a defendant’s counterallegations.” 720 F.3d 33, 45 (1st Cir. 2013) (citing

Twombly, 550 U.S. at 555–56). The decision below

adopts the opposite approach by crediting a benign explanation for the challenged conduct at the Rule

12(b)(6) stage rather than permitting discovery to test

that explanation once a plausible inference of unlawful

conduct has been pleaded.

The Fourth Circuit has adopted a similar framework. In McCleary-Evans v. Maryland Dept. of Transportation, the court dismissed a discrimination claim

because the allegations were “consistent with” lawful

hiring practices and failed to plausibly support an inference of discriminatory intent. 780 F.3d 582, 586

2 See also, Mator v. Wesco Distrib., Inc., 102 F.4th 172, 184–85

(3d Cir. 2024) (explaining that dismissal may be warranted

where a defendant’s alternative explanation is “obvious,” “natural,” or “more likely” than the plaintiff’s theory, citing Ashcroft

v. Iqbal, 556 U.S. 662, 680 (2009)); Doe v. Emory Univ., 110

F.4th 1254, 1258–60, 1262–63 (11th Cir. 2024) (applying Doe v.

Samford Univ., 29 F.4th 675 (11th Cir. 2022), and affirming dismissal where allegations were “consistent with” an “obvious alternative explanation” suggesting lawful conduct).

9

(4th Cir. 2015). Although the court acknowledged that

discriminatory intent was “possible,” it concluded that

the complaint did not plausibly allege discrimination

in light of an “obvious alternative explanation”—

namely, that the selected candidates were viewed as

more qualified—an explanation the court treated as

defeating plausibility at the pleading stage. Id. at 588.

The Fifth Circuit’s decisions reflect tensions within

the district. In U.S. ex rel. Integra Med Analytics,

L.L.C. v. Baylor Scott & White Health, the court affirmed dismissal at the pleading stage by crediting a

lawful “obvious alternative explanation” for the defendant’s conduct—namely, that the defendant was

ahead of industry peers in implementing updated

Medicare reimbursement guidelines—concluding that

allegations merely “consistent with” fraud failed to

satisfy plausibility. 816 F. App’x 892, 897–900 (5th

Cir. 2020). By contrast, in Pickett v. Texas Tech Univ.

Health Sciences Ctr., the court rejected defendants’ reliance on asserted nondiscriminatory explanations at

the Rule 12(b)(6) stage, emphasizing that plausibility

does not require the plaintiff’s inference to be the most

likely explanation and that courts may not credit benign explanations once the complaint plausibly alleges

unlawful conduct. 37 F.4th 1013, 1033–35 (5th Cir.

2022) Taken together, these cases illustrate the uncertainty within the Fifth Circuit surrounding the proper

role of “obvious alternative explanations” at the pleading stage—a confusion that has led lower courts to inconsistently weigh competing inferences rather than

uniformly applying Rule 12(b)(6)’s requirement that

plausible allegations be accepted as true.

Across circuits, plausibility has been converted into

a comparative probability inquiry. Plaintiffs are

10

required to plead facts sufficient to overcome defendants’ asserted benign explanations before discovery.

B. Five Circuits Correctly Hold That Rule

12(b)(6) Does Not Permit Courts to Choose

Between Two Plausible Inferences

In contrast, the Second, Seventh, Eighth, Ninth,

and D.C. Circuits have consistently held that courts

may not resolve factual ambiguity by choosing between competing plausible explanations at the pleading stage.

The Second Circuit, in particular, has repeatedly

emphasized that Rule 12(b)(6) forbids courts from

weighing inferences. In Anderson News, L.L.C. v.

American Media, Inc., the court reversed dismissal

where the district court credited defendants’ lawful explanations for their conduct and rejected the plaintiffs’

anticompetitive theory, emphasizing that at the Rule

12(b)(6) stage courts must draw all reasonable inferences in the plaintiff’s favor and may not dismiss

merely because defendants’ explanations are also

plausible. 680 F.3d 162, 168, 184–85 (2d Cir. 2012).

More recently, the Second Circuit reaffirmed that

courts may not assess credibility or weigh competing

explanations at the pleading stage, stressing that “the

test is whether the complaint is plausible, not whether

it is less plausible than an alternative explanation,”

and that such determinations are reserved for the jury.

Palin v. N.Y. Times Co., 940 F.3d 804, 812–14, 816 (2d

Cir. 2019).

The D.C. Circuit has applied the same rule. In VoteVets Action Fund v. Dept. of Veterans Affairs, the court

reversed a Rule 12(b)(6) dismissal, explaining that the

existence of a plausible alternative explanation for the

11

government’s conduct—even one that might ultimately prove true—does not permit dismissal where

the complaint plausibly alleges unlawful action. 992

F.3d 1097, 1104–07 (D.C. Cir. 2021). The court emphasized that it is not the judiciary’s role at the pleading

stage to speculate which competing explanation will

prevail after discovery. Id.

The Ninth Circuit has applied this principle expressly in the supervisory-liability context. The court

held that a plaintiff need not negate alternative explanations for a supervisor’s inaction at the pleading

stage, explaining that where both the plaintiff’s and

the defendant’s explanations are plausible, the complaint survives dismissal. Starr v. Baca, 652 F.3d

1202, 1216–17 (9th Cir. 2011) (citing Twombly, 550

U.S. at 555–56). The court further explained that a supervisor’s knowledge, deliberate indifference, and acquiescence may be plausibly inferred from allegations

of notice of repeated constitutional violations coupled

with a failure to act. Id. at 1206–08, 1215–16. At the

Rule 12(b)(6) stage, the court emphasized, plausibility

does not require probability, and discovery—not

threshold dismissal—is the mechanism for testing

which explanation ultimately proves correct. Id. at

1216–17.

The Seventh Circuit agrees. In Hughes v. Northwestern University, the court reversed dismissal of

ERISA claims, explaining that plausibility does not require a plaintiff to conclusively rule out alternative explanations for a defendant’s conduct and that a court’s

role at the pleading stage is “to decide whether the

plaintiff’s allegations are plausible—not which side’s

version is more probable.” 63 F.4th 615, 629–31 (7th

Cir. 2023). Where competing inferences are

12

reasonable, the court stressed, the complaint survives

and the merits must be tested through further factual

development rather than threshold dismissal.

Finally, the Eighth Circuit reversed a Rule 12(b)(6)

dismissal after concluding that the district court improperly drew inferences in defendants’ favor and

faulted the plaintiff for failing to negate lawful explanations for the challenged conduct. Braden v. WalMart Stores, Inc., 588 F.3d 585, 595–96 (8th Cir. 2009).

As the court explained, “[i]t is not Braden’s responsibility to rebut these possibilities in his complaint,” and

the district court erred by “finding the complaint inadequate for failing to rule out potential lawful explanations for appellees’ conduct,” including the assertion

that appellees “could have chosen funds with higher

fees for any number of reasons, including potential for

higher return, lower financial risk, more services offered, or greater management flexibility.” Id. at 596.

The court emphasized that Rule 8 does not require

plaintiffs to plead facts rebutting every lawful explanation and that imposing such a burden would improperly convert plausibility into a probability requirement. Id. at 596–97.

Subsequent Eighth Circuit decisions have applied

Twombly’s plausibility framework while reaffirming

that Rule 12(b)(6) requires factual allegations sufficient to support a reasonable inference of liability, not

proof or probability. See In re Pre-Filled Propane Tank

Antitrust Litigation, 860 F.3d 1059, 1069–70 (8th Cir.

2017) (en banc) (explaining that a complaint must allege factual enhancement beyond parallel conduct or

conclusory assertions, but need not establish liability

at the pleading stage).

13

These decisions apply this Court’s pleading framework as written. When a complaint alleges facts supporting a rational inference of liability—including supervisory knowledge or ratification—the case proceeds

to discovery, even if a defendant’s explanation may

later prove more persuasive.

III. THE PRACTICE OF WEIGHING COMPETING EXPLANATIONS AT THE PLEADING

STAGE EXCEEDS JUDICIAL COMPETENCE

AND DISPLACES THE STRUCTURAL ROLE

OF DISCOVERY AND FACT-FINDING

A. Crediting Facially Lawful Explanations at

the Pleading Stage Collapses the Distinction Between Pleading, Discovery, and

Fact-Finding

The Federal Rules establish a sequence: pleading

tests whether the plaintiff has stated a legally plausible claim; discovery develops the evidentiary record;

summary judgment assesses whether genuine disputes of material fact remain; and trial resolves contested factual questions. Rule 12(b)(6) serves a limited

and well-defined function within the architecture of

the Federal Rules. It screens for legal sufficiency, not

evidentiary superiority. When courts dismiss complaints by crediting a defendant’s asserted lawful explanation over a plaintiff’s plausible inference of unlawful conduct, they collapse the carefully sequenced

stages of adjudication and convert plausibility review

into premature fact resolution.

Courts and commentators have warned that plausibility review can be misapplied in ways that resemble summary judgment-style comparative inference

analysis. See A. Benjamin Spencer, Plausibility

14

Pleading, 50 B.C. L. Rev. 431, 447 n.93 (2009) (warning that heightened scrutiny may “mov[e] forward

summary judgment-like screening to the pleading

phase”); see also Arthur R. Miller, From Conley to

Twombly to Iqbal, 60 Duke L.J. 1, 50–53 (2010) (observing that the gatekeeping function of summary

judgment risks migrating into Rule 12(b)(6)). Properly

understood, plausibility is a test of legal sufficiency,

not a comparative assessment of which competing factual inference is more probable. When courts choose

among competing reasonable inferences at the pleading stage, they collapse the Federal Rules’ distinction

between pleading and evidentiary testing.

Expanding plausibility into comparative probability review also produces perverse systemic effects. If

plaintiffs must anticipate and negate defendants’ asserted benign explanations to survive dismissal, rational litigants will respond by filing increasingly

lengthy and defensive complaints, attempting to plead

around every conceivable lawful characterization of

the conduct at issue. That is inconsistent with Rule 8’s

instruction that a complaint contain a “short and plain

statement” of the claim. Fed. R. Civ. P. 8(a)(2). Rather

than streamlining litigation, converting plausibility

into a probability requirement encourages over-pleading, multiplies motion practice, and burdens judicial

dockets with precisely the kind of sprawling complaints the Federal Rules were designed to avoid.

The problem is not merely formal. At the pleading

stage, courts lack the tools to evaluate the relative

strength of competing factual narratives. They have no

access to internal communications, no opportunity for

cross-examination, no evidentiary context, and no developed factual record. Judicial experience and

15

common sense cannot substitute for adversarial testing where the complaint supports competing reasonable inferences. See Twombly, 550 U.S. at 557 (explaining that plausibility “does not impose a probability requirement at the pleading stage”).

By resolving factual ambiguity in favor of a defendant’s asserted lawful explanation, courts exceed the

limited function of Rule 12(b)(6). Plausibility doctrine

was designed to screen out complaints that fail to allege sufficient factual matter to support a reasonable

inference of liability, not to authorize judges to weigh

competing inferences and select the one that appears

more benign. When lower courts adopt the latter approach, they do not merely apply plausibility pleading,

they restructure it.

Preserving the distinction between legal sufficiency

and factual adjudication is not a technical concern. It

is essential in maintaining the integrity of the Federal

Rules’ system of adjudication. Rule 12(b)(6) ensures

that a complaint alleges enough to proceed. It does not

authorize courts to decide which of two plausible explanations is more convincing before discovery begins.

B. Requiring Plaintiffs to Negate Benign Explanations Before Discovery Magnifies Information Asymmetry and Undermines

Uniform Federal Procedure

The consequences of inference-weighing at the

pleading stage are particularly acute in public law,

civil rights, supervisory, and Monell-liability cases.

There, evidence of intent, ratification, knowledge, and

institutional motive resides almost entirely within the

defendant’s control. When courts require plaintiffs to

disprove asserted lawful explanations before

16

discovery, they transform informational asymmetry

into a dispositive barrier to adjudication.

These concerns are especially acute here. Petitioner alleged that certain de facto policies existed at

the school allowing for “social transitioning” a student’s gender without notifying the parents. The

school said it was following the law. Discovering

whether an unwritten policy exists is inherently difficult, and it would require examining memos, conversations, team meetings, and other sorts of ephemeral

and difficult-to-obtain evidence.

This Court’s pleading jurisprudence does not impose such a burden. Rule 8 does not require plaintiffs

to plead facts rebutting every conceivable lawful explanation for a defendant’s conduct. Twombly, 550 U.S. at

557. It does not demand that the plaintiff’s inference

be the most likely explanation, nor that the complaint

negate all benign alternatives.

As discussed in Part II.B, several courts of appeals

have recognized that requiring plaintiffs to eliminate

alternative explanations at the pleading stage would

improperly convert plausibility into probability. These

decisions reflect a fundamental institutional reality: in

cases alleging unconstitutional motive, ratification, or

deliberate indifference, the most probative evidence—

internal communications, deliberative records, supervisory directives—lies within the defendant’s possession. Relevant state statutes, regulations, and guidelines may be publicly available, but the evidence for

how officials interpreted and implemented guidelines

is not. Requiring plaintiffs to negate defendants’ asserted benign explanations before discovery effectively

demands proof without access to evidence.

17

Scholars have identified this dynamic as one of the

central risks of expansive plausibility review. As Prof.

Alexander Reinert has observed, heightened pleading

burdens disadvantage plaintiffs in cases where critical

facts are uniquely within the defendant’s control. Alexander A. Reinert, The Burdens of Pleading, 162 U.

Pa. L. Rev. 1767, 1780–84 (2014). When courts treat

informational asymmetry as a reason to dismiss rather than as a reason to permit discovery, they invert

the logic of the Federal Rules.

That dynamic produces geographic differentiation

in the application of federal pleading standards. As

discussed above, some circuits permit cases to proceed

when competing inferences are plausible, reserving

resolution for discovery and fact-finding. Others dismiss when a lawful explanation appears more persuasive at the outset. The result is that similarly pleaded

complaints may survive in some jurisdictions but not

others, creating significant variation in access to discovery under a rule meant to operate uniformly.

IV.THE DECISION BELOW PRESENTS A

CLEAN

VEHICLE

FOR

RESOLVING

WHETHER COURTS MAY CREDIT FACIALLY LAWFUL ALTERNATIVE EXPLANATIONS AT THE PLEADING STAGE

This case arrives at the Court solely because the

lower courts credited an alternative explanation over

plaintiff’s plausible claims at the 12(b)(6) stage. The

case has not moved beyond that baseline issue, so

there are no accompanying issues of fact-finding, discovery, evidence, or jurisdiction—and there are certainly no questions of standing. Thus, this case is an

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excellent vehicle for this Court to resolve this recurring and important issue.

Petitioner made two main claims based on the facts

alleged in the complaint: either that the school had an

unwritten de facto policy on withholding information

about gender transitioning from parents, or that the

de facto policy exists now because the school subsequently ratified the employees’ actions. Pet. at 3. The

First Circuit did not hold that the theories were legally

foreclosed as possible valid claims. Nor did it hold that

the alleged conduct could not, as a matter of law, constitute concealment.

Instead, the First Circuit dismissed the complaint

by crediting the school board’s asserted explanation

that its actions reflected compliance with state privacy

law rather than approval of the underlying misconduct. In doing so, the court accepted the board’s own

characterization of its institutional intent—an assertion that it was merely interpreting state law—as dispositive at the pleading stage. That approach resolved

factual ambiguity in favor of the defendant and treated

a contested explanation of motive as established fact

before discovery.

The decision below thus implicates the precise legal

question presented in the petition. Because the First

Circuit’s analysis turns entirely on the application of

pleading doctrine—rather than on disputed facts, evidentiary rulings, or jurisdictional defects—this case

presents an especially suitable vehicle for resolving

that question.

CONCLUSION

This case presents a recurring and outcome-determinative disagreement among the courts of appeals

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about how Rule 12(b)(6) applies when a defendant offers a facially lawful alternative explanation for the

pleaded facts. The consequences of that division are

significant.

Because Rule 12(b)(6) is a federal procedural rule,

its application should not vary in a way that makes

access to discovery turn on circuit geography. This

case presents a clean and purely procedural vehicle for

clarifying whether plausibility is a measure of legal

sufficiency or a license for comparative fact-weighing

at the pleading stage.

The petition should be granted.

Respectfully submitted,

Ilya Shapiro

Counsel of Record

Trevor Burrus

MANHATTAN INSTITUTE

52 Vanderbilt Ave.

New York, NY 10017

(212) 599-7000

ishapiro@manhattan.institute

February 23, 2026