Amicus Curiae Brief — International Partners for Ethical Care, Inc., et al., Petitioners v. Bob Ferguson, Governor of Washington, et al.

No. 25-840

In the Supreme Court of the United States

INTERNATIONAL PARTNERS FOR ETHICAL CARE, INC., ET

AL.,

Petitioners,

v.

ROBERT FERGUSON, GOVERNOR OF WASHINGTON, ET

AL.,

Respondents.

ON APPEAL FROM THE UNITED STATES COURT OF

APPEALS FOR THE NINTH CIRCUIT

BRIEF OF FLORIDA, IDAHO, AND 20 STATES

AS AMICI CURIAE FOR PETITIONERS

RAÚL LABRADOR

Attorney General

MICHAEL ZARIAN

Solicitor General

Office of the Idaho

Attorney General

700 W. Jefferson St.

Suite 210

Boise, ID 83720

September 15, 2026

JAMES UTHMEIER

Attorney General

DAVID M.S. DEWHIRST*

Solicitor General

*Counsel of Record

JASON J. MUEHLHOFF

Chief Deputy Solicitor General

THOMAS F. KELLY, IV

Assistant Solicitor General

ALEXZONDRA MATTSON

Solicitor General Fellow

Office of the Florida

Attorney General

PL-01, The Capitol

Tallahassee, FL 32399

david.dewhirst@myfloridalegal.com

Counsel for Amici Curiae

ii

TABLE OF CONTENTS

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

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

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

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

I.

Parental rights are among the oldest

and most established rights in our legal

tradition. ................................................ 4

II.

Family liberty interests are entrenched

in Anglo-American society and flow

from natural order............................... 12

III. Petitioners have standing. .................. 14

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

ADDITIONAL SIGNATORIES................... 20

iii

TABLE OF AUTHORITIES

Cases

Bost v. Illinois,

607 U.S. 71 (2026) ................................................. 15

Brown v. Ent. Merchants Ass’n,

564 U.S. 786 (2011) ............................................. 5, 6

Calabretta v. Floyd,

189 F.3d 808 (9th Cir. 1999) ................................... 1

California v. Azar,

911 F.3d 558 (9th Cir. 2018) ................................. 17

City & Cnty. of S.F. v. USCIS,

981 F.3d 742 (9th Cir. 2020) ................................. 17

Deanda v. Becerra,

96 F.4th 750 (5th Cir. 2024).................................. 14

Dep’t of Com. v. New York,

588 U.S. 752 (2019) ......................................... 16, 17

Diamond Alternative Energy v. Env’t Prot. Agency,

606 U.S. 100 (2025) ............................................... 16

Frazier v. Frazier,

147 So. 464 (Fla. 1933) ........................................ 5, 6

Gruenke v. Seip,

225 F.3d 290 (3d Cir. 2000) ................................... 14

In re J.P.,

648 P.2d 1364 (Utah 1982).............................. 12, 13

In re Luscier’s Welfare,

524 P.2d 906 (Wash. 1974) .................................... 12

Keohane v. Fla. Dep’t of Corr. Sec’y,

952 F.3d 1257 (11th Cir. 2020) ............................... 9

Lacher v. Venus,

188 N.W. 613 (Wis. 1922). ..................................... 13

Lujan v. Def’s of Wildlife,

504 U.S. 555 (1992) ............................................... 16

iv

Mahmoud v. Taylor,

606 U.S. 522 (2025) ................................................. 7

May v. Anderson,

345 U.S. 528 (1953) ................................................. 1

McDonald v. City of Chicago, Ill.,

561 U.S. 742 (2010) ................................................. 3

Meyer v. Nebraska,

262 U.S. 390 (1923) ............................................. 1, 7

Parham v. J.R.,

442 U.S. 584 (1979) ..........................4, 5, 8, 9, 12, 14

Pennsylvania v. West Virginia,

262 U.S. 553 (1923) ............................................... 17

Pierce v. Soc’y of the Sisters of the Holy Names of Jesus & Mary,

268 U.S. 510 (1925) ................................................. 7

Prince v. Massachusetts,

321 U.S. 158 (1944) ........................................... 8, 14

Raskin on behalf of JD v. Dallas Indep. Sch. Dist.,

69 F.4th 280 (5th Cir. 2023).................................. 13

Reno v. Flores,

507 U.S. 292 (1993) ................................................. 7

Santosky v. Kramer,

455 U.S. 745 (1982) ................................................. 4

Smith v. Org. of Foster Fams. For Equal. & Reform,

431 U.S. 816 (1977) ............................................... 12

Spokeo, Inc. v. Robins,

578 U.S. 330 (2016) ............................................... 15

Stanley v. Illinois,

405 U.S. 645 (1972) ............................................. 1, 7

State ex rel. Sparks v. Reeves,

97 So. 2d 18 (Fla. 1957) ........................................... 6

State v. Loe,

692 S.W.3d 215 (Tex. 2024)..................................... 9

Susan B. Anthony List v. Driehaus,

573 U.S. 149 (2014) ............................................... 17

v

The Etna,

8 F. Cas. 803 (D. Me. 1836) ................................... 14

Thole v. U.S. Bank N.A.,

590 U.S. 538 (2020) ............................................... 15

Troxel v. Granville,

530 U.S. 57 (2000) ........................................... 3, 4, 5

United States v. Skrmetti,

605 U.S. 495 (2025) ........................................... 9, 10

Vernonia Sch. Dist. 47J v. Acton,

515 U.S. 646 (1995) ................................................. 6

Virginia v. Am. Booksellers Ass’n,

484 U.S. 383 (1988) ............................................... 16

Washington v. Glucksberg,

521 U.S. 702 (1997) ................................................. 7

Watland v. Hurley,

183 So. 255 (Fla. 1938) ............................................ 6

Wisconsin v. Yoder,

406 U.S. 205 (1972) ........................................... 7, 12

Statutes

Wash.Rev.Code §70.02.010(15) .................................. 2

Wash.Rev.Code §70.02.240 ........................................ 2

Wash.Rev.Code §70.02.265 ........................................ 2

Wash.Rev.Code §71.24.025(42) .................................. 2

Wash.Rev.Code §71.34.430 ........................................ 2

Wash.Rev.Code §74.09.675(2), (3) ............................. 2

Other Authorities

A. Scalia, The Doctrine of Standing as an Essential

Element of the Separation of Powers, 17 Suffolk U.

L. Rev. 881 (1983) .................................................. 15

vi

Adele Diamond, Normal Development of Prefrontal

Cortex from Birth to Young Adulthood: Cognitive

Functions, Anatomy, and Biochemistry, in Principles of Frontal Lobe Function (D. Stuss & R.

Knight eds., 2002) ................................................... 7

Ashley J. DiMella, Detransitioner Chloe Cole Shares

Complications After Gender Procedures: “I Am

Grieving”, Fox News (Dec. 18, 2025) .................... 11

Chloe K. Jones, The Façade of Medical Consensus:

How Medical Associations Prioritize Politics Over

Science, 2025 Harv. J.L. & Pub. Pol’y Per Curiam

(2025) ..................................................................... 10

Christina Buttons, The Tragedy of Yarden Silveira,

City Journal (Mar. 12, 2025)................................. 11

Circular on the Legal Rights of Children, U.S. Dep’t

of the Interior, Bureau of Educ. No. 3-1880 (1880)

................................................................................ 14

Disease, Merriam-Webster.com Dictionary (2026)...11

Ferdinand Schoeman, Parental Discretion and Children’s Rights: Background and Implications for

Medical-Decision-Making, 10 J. Med. & Phil. 45

(1985) ....................................................................... 6

Frances Williamson, The Meaning of “Public Meaning”: An Originalist Dilemma Embodied by Mahanoy Area School District, 46 Harv. J.L. & Pub. Pol’y

257 (2023) .............................................................. 14

H. Maine, Ancient Law (1st American ed. 1870) .... 13

Hilary Cass, Independent review of gender identity

services for children and young people 158–64

(2024) ..................................................................... 10

John Locke, Second Treatise of Government

(1690) .................................................................... 5, 13

Kristine Parks, We Cannot Endorse: Why the Nation’s Plastic Surgeons are Pulling Back on Youth

Gender Surgery, Fox News (Feb. 9, 2026), ..... 10, 11

vii

Lawson B. Hamilton, Parent, Child, and State: Regulation in A New Era of Homeschooling, 51 J.L. &

Educ. 45 (2022) ...................................................... 13

Medicine, Merriam-Webster.com Dictionary (2026)

................................................................................ 11

Melissa Moschella, Natural Law, Parental Rights

and Education Policy, 59 Am. J. Juris. 197 (2014)

................................................................................ 14

Melissa Moschella, Natural Law, Parental Rights,

and the Defense of “Liberal” Limits on Government,

98 Notre Dame L. Rev. 1559 (2023)...................... 14

Sarah C. J. Jorgensen, Transition Regret and Detransition: Meanings and Uncertainties, 52 Arch.

Sex Behav. 2173 (2023), ........................................ 10

Toby L. Ditz, Ownership and Obligation: Inheritance

and Patriarchal Households in Connecticut, 17501820, 47 Wm. & Mary Q. 235 (1990) ...................... 6

1 Joseph Story, Commentaries on Equity Jurisprudence (1839) ......................................................... 5, 8

1 William Blackstone, Commentaries on the Laws of

England (1753) .................................................... 5, 6

1 William Blackstone, Commentaries on the Laws of

England (1765) .................................................... 5, 6

2 James Kent, Commentaries on American Law

(1873) ............................................................. 5, 8, 13

2 Samuel Pufendorf, The Whole Duty of Man According to the Law of Nature (1735) .............................. 5

1

INTEREST OF AMICI CURIAE 1

Amici States of Florida, Idaho, and 20 States

(“Amici States”) support parents’ fundamental right to

direct the upbringing of their minor children—a right

this Court has described as “essential” and “far more

precious . . . than property rights.” Stanley v. Illinois,

405 U.S. 645, 651 (1972) (first quoting Meyer v. Nebraska, 262 U.S. 390, 399 (1923); and then May v. Anderson, 345 U.S. 528, 533 (1953)). A state’s “interest

in the welfare of children embraces not only protecting

children from physical abuse, but also protecting children’s interest in the privacy and dignity of their

homes and in the lawfully exercised authority of their

parents.” Calabretta v. Floyd, 189 F.3d 808, 820 (9th

Cir. 1999). Washington’s law undermines other

States’ ability to safeguard those interests. And no

one in Jacksonville or Coeur d’Alene voted to relinquish their God-given parental rights to politicians in

Olympia. Yet Washington’s law divests parents in

Amici States of those rights. That’s the point.

SUMMARY OF ARGUMENT

Parental rights are fundamental and foundational.

Parents—not the government—wield ultimate responsibility for the care, formation, and well-being of

their children.

These rights are under attack in Washington,

where youth shelters may choose not to notify parents

1 Timely notice pursuant to Rule 37 has been provided to parties’ counsel.

2

of their child’s safety, health, or location so long as

their runaway child seeks “gender-affirming treatment.” 2 The statute authorizing youth shelters to

harbor these minors harms parents by denying their

right to consent to or refuse treatment for their child,

including “gender-affirming care” or other medical

services. And those medical services aren’t limited to

mental health, they include “[f]acial feminization surgeries”; “facial gender-affirming treatment”; “tracheal

shaves, hair electrolysis,” “mastectomies, breast reductions, breast implants, or any combination of gender-affirming procedures,” Wash.Rev.Code

§74.09.675(2)(b).

Parents also suffer by not receiving any notice of

their child’s presence at the shelter—per Washington,

parents need not be informed if their runaway child is

even alive. And even if the shelter chooses to notify

parents, the child’s location and medical records 3 may

2 “[G]ender-affirming treatment” is “a service or product that

a health care provider . . . prescribes to an individual to support

and affirm the individual’s gender identity.” Wash.Rev.Code

(RCW) §74.09.675(3). This includes physical or mental health

services. Id. §70.02.010(15). In Washington, “[g]ender-affirming

treatment includes, but is not limited to, treatment for gender

dysphoria,” and “can be prescribed to two spirit, transgender,

nonbinary, and other gender diverse individuals.” Id.

§74.09.675(3).

3 When the child receives gender-affirming treatment, the

state then restricts the parents’ rights to access the child’s mental health “treatment records.” RCW §71.24.025(42) (App.K); id.

§71.34.430 (App.L) (limiting disclosure to parents); id.

§70.02.240 (App.I) (limiting parent’s access to a minor’s records,

except under prescribed circumstances); id. §70.02.265 (App.J)

(allowing therapist to deny parents access).

3

be withheld and their return delayed significantly or

indefinitely.

Yet the Ninth Circuit held that Petitioners lacked

standing because their harms were deemed self-inflicted and not sufficiently immediate or certain. This

crabbed view of standing meant turning a blind eye to

Washington’s encroachment on constitutional rights,

allowing the state to “not merely invad[e] Petitioner’s

parental rights,” but “obliterate them.” App.47a (VanDyke, J., dissenting) (cleaned up).

As this Court has recognized, “the interest of parents in the care, custody, and control of their children”

“is perhaps the oldest of the fundamental liberty interests recognized by this Court.” Troxel v. Granville,

530 U.S. 57, 65 (2000) (plurality opinion). And the

Fourteenth Amendment exists “to enforce constitutionally declared rights against the States.” McDonald v. City of Chicago, Ill., 561 U.S. 742, 833 (2010)

(Thomas, J., concurring). But Washington has determined that it knows better. Luckily, our Constitution

places the burden on governments to respect fundamental rights, not on citizens to claw back the right to

parent their own children. The decision below inverted that constitutional reality.

ARGUMENT

What the Ninth Circuit deemed a “some day” injury

actually inflicts an every-day injury on Washington

parents. App.21a. Every day, Petitioners have less

authority over the custody and care of their children

than they did before Washington’s runaway-child law

was enacted. And every day, that lack of authority

colors the parent-child dynamic between Petitioners

4

and their children. The threat that Petitioners’ children will exercise their statutory right to run away

and seek irreversible life-changing treatment looms

over every interaction Petitioners have with their children.

This Court must reverse for three reasons. First,

parental rights are among the oldest fundamental

rights that this Court has recognized. They play a

bedrock role in American society—and in every functional society. Second, family liberty interests are

deeply entrenched in history and flow from the natural order. Third, Washington’s encroachment on parental rights was sufficient to give Petitioners

standing.

I.

Parental rights are among the oldest and

most established rights in our legal tradition.

Courts have long acknowledged the importance of

empowering parents “to make decisions concerning

the care, custody, and control of their children.”

Troxel, 530 U.S. at 66 (plurality opinion); see also Santosky v. Kramer, 455 U.S. 745, 753 (1982) (acknowledging “this Court’s historical recognition that

freedom of personal choice in matters of family life is

a fundamental liberty interest”). Such rights are “perhaps the oldest of the fundamental liberty interests

recognized.” Troxel, 530 U.S. at 65. Because children

are unable “to make sound judgments concerning

many decisions,” and because parents are “presum[ed]” to “act in the best interests of their children,”

the Court has understood our Constitution to incorporate “broad parental authority over minor children.”

Parham v. J.R., 442 U.S. 584, 602–03 (1979) (first and

5

fourth quotes); Troxel, 530 U.S. at 68 (plurality) (second and third quotes).

History and tradition undergird this Court’s precedents recognizing parental rights. As early commentators recognized, children do not understand “how to

govern themselves.” 2 Samuel Pufendorf, The Whole

Duty of Man According to the Law of Nature 202

(1735). Their “wants and weaknesses” thus “render it

necessary that some person maintains them” until

adulthood. 2 James Kent, Commentaries on American

Law 190 (1873); 1 William Blackstone, Commentaries

on the Laws of England 447 (1753); Pufendorf, The

Whole Duty of Man at 202; see also Brown v. Ent. Merchants Ass’n, 564 U.S. 786, 828–29 (2011) (Thomas, J.,

dissenting). Parents are best suited to the job. They

have traditionally been entrusted as “the most fit and

proper person[s]” for that task. Kent, American Law

at 190; accord 1 Joseph Story, Commentaries on Equity Jurisprudence § 1341 (1839) (“parents are entrusted with the custody” of their children “upon the

natural presumption that the children will be

properly taken care of”).

Parents are entrusted with these rights because

they bear corresponding duties to their children that

arise from the nature of the parent-child relationship.

When parents beget children, they are “by the law of

nature, under an obligation to preserve, nourish, and

educate the children.” John Locke, Second Treatise of

Government § 56 (1690); Frazier v. Frazier, 147 So.

464, 466 (Fla. 1933) (These duties “are thrown upon

parents by the laws of nature as well as of society and

the state.”). Parental duties “principally consist” of

the “maintenance, [] protection, [] and education” of

children, Blackstone, Commentaries at 422 (1765),

6

and boast a pedigree “older than the common law itself,” State ex rel. Sparks v. Reeves, 97 So. 2d 18, 20

(Fla. 1957). “[D]erived from . . . their dut[ies],” parents’ rights to custody and “lawful correction” follow.

Blackstone, Commentaries at 422 (1765); see also Frazier, 147 So. at 466 (parents possess a “natural, inherent, and consequently legal, right . . . to have the

custody of their children”); Watland v. Hurley, 183 So.

255, 256 (Fla. 1938) (custody over one’s child is “the

natural and equitable right of the parent”).

Equally, the common law equipped parents with robust parental rights. “[H]ousehold heads” were empowered to “speak for their dependents in dealings

with the larger world,” Toby L. Ditz, Ownership and

Obligation: Inheritance and Patriarchal Households

in Connecticut, 1750-1820, 47 Wm. & Mary Q. 235,

236 (1990), and parents enjoyed the “right . . . to govern their children’s growth,” Brown, 564 U.S. at 828

(Thomas, J., dissenting); cf. Blackstone, Commentaries at 440 (parental consent “to the marriage of his

child under age . . . is absolutely necessary”); see also

Vernonia Sch. Dist. 47J v. Acton, 515 U.S. 646, 654

(1995) (“Traditionally at common law, and still today,

unemancipated minors lack some of the most fundamental rights of self-determination—including even

the right of liberty in its narrow sense, i.e., the right

to come and go at will.”).

Developments in medical and social science have

unsurprisingly confirmed the wisdom of our tradition

of parental rights. Longstanding research shows that

children lack the ability to “deliberate maturely” toward their own best interests. Ferdinand Schoeman,

Parental Discretion and Children’s Rights: Background and Implications for Medical-Decision-Making, 10 J. Med. & Phil. 45, 46 (1985). As any parent

7

knows, children often make poor decisions because

they lack life experience. Medical science also tells us

that children make these poor decisions because their

prefrontal cortex, the portion of the brain that deals

with reasoning and long-term consequences, is underdeveloped. 4

Taking care to give a “careful description” of the

scope of parental rights, Washington v. Glucksberg,

521 U.S. 702, 721 (1997), the Court has recognized a

parent’s right to direct their child’s education, see

Meyer, 262 U.S. at 400; Pierce v. Soc’y of the Sisters of

the Holy Names of Jesus & Mary, 268 U.S. 510, 534–

35 (1925), direct religious upbringing, see Wisconsin v.

Yoder, 406 U.S. 205, 214 (1972), and maintain a relationship with the child born out of wedlock, see Stanley, 405 U.S. at 651. See also Mahmoud v. Taylor, 606

U.S. 522, 559 (2025) (“We reject this chilling vision of

the power of the state to strip away the critical right

of parents to guide the religious development of their

children.”). Parents hold these rights regardless of

the government’s view of “[t]he best interests of the

child . . . so long as certain minimum requirements of

child care are met.” Reno v. Flores, 507 U.S. 292, 304

(1993) (cleaned up).

In particular, this case implicates two areas of wellsettled parental rights: the right to physical custody

of a child and the right to make decisions regarding a

4 See Adele Diamond, Normal Development of Prefrontal Cortex from Birth to Young Adulthood: Cognitive Functions, Anatomy, and Biochemistry, in Principles of Frontal Lobe Function

466 (D. Stuss & R. Knight eds., 2002) (noting that the pre-frontal

cortex takes “over two decades to reach full maturity”),

https://perma.cc/94YJ-MP38.

8

child’s “medical care or treatment.” Parham, 442 U.S.

at 603.

As for custody, “[i]t is cardinal . . . that the custody

. . . of the child reside first in the parents.” Prince v.

Massachusetts, 321 U.S. 158, 166 (1944) (emphasis

added). Historically, a father could “obtain the custody of his children by the writ of habeas corpus, when

they are improperly detained from him.” Kent, American Law at 202; Story, Equity Jurisprudence § 1341

(agreeing and noting that custody may also be sought

by petition).

As for the right to guide a child’s medical care, historical sources don’t thoroughly elaborate precisely

because “[i]n an earlier day, the problems inherent in

coping with children afflicted with mental or emotional abnormalities were dealt with largely within

the family.” Parham, 442 U.S. at 598. The parental

right to make medical decisions has become more salient as “states have expanded their efforts to assist

the mentally ill” and physically ill in ways that conflict with the parental right. Id. at 599.

Still, the Court has given guidance as to the scope

and supporting rationale of the parental right to make

medical decisions for a child. As the Court has explained, “children, even in adolescence, simply are not

able to make sound judgments concerning many decisions, including their need for medical care or treatment.” Parham, 442 U.S. at 603. “Parents can and

must make those judgments.” Id. “Simply because

the decision is not agreeable to the child or because it

involves risks does not automatically transfer the

power to make that decision from the parents to some

agency or officer of the state.” Id. Thus, whereas a

“child may balk at hospitalization or complain about

9

a parental refusal to provide cosmetic surgery,” a parent typically will know better and should have the

“authority to decide what is best for the child.” Id. at

604. Parents may only exercise that authority to protect the child, not expose the child to harm. See State

v. Loe, 692 S.W.3d 215, 249 (Tex. 2024) (Blacklock, J.,

concurring) (“A parental right to use drugs or surgery

to disrupt or destroy a child’s normal biological functions is not objectively, deeply rooted in this Nation’s

history and tradition.” (internal quotation marks

omitted)).

The need for parental involvement and oversight

grows in importance when a State’s preferred ideology

ignores basic reality about the two sexes and further

confuses innocent and impressionable children experiencing “gender dysphoria”—a condition characterized as “distress that may accompany the

incongruence between one’s experienced or expressed

gender and one’s assigned gender.” Keohane v. Fla.

Dep’t of Corr. Sec’y, 952 F.3d 1257, 1262 (11th Cir.

2020). Some seek to treat gender dysphoria with socalled “gender-affirming care,” which employs social,

mental-health, and physical interventions to treat a

person in line with his or her preferred gender. See

id. at 1263.

But there are “fierce scientific and policy debates

about the safety, efficacy, and propriety of” these

treatments. United States v. Skrmetti, 605 U.S. 495,

525 (2025). Recent reports reveal that this treatment

10

“can concretize gender dysphoria” and may not “improve[] mental health status in the short term.” 5

Worse still, “de-transition and/or regret could be more

frequent than previously reported” for individuals suffering from “adolescent-onset gender dysphoria,” and

these types of treatment may lead to “irreversible effects.” 6 Indeed, even “social transitions” are serious

psychosocial interventions that have shown long-term

negative consequences on mental health. 7

5 Sarah C. J. Jorgensen, Transition Regret and Detransition:

Meanings and Uncertainties, 52 Arch. Sex Behav. 2173, 2173–84

(2023), https://perma.cc/32EU-BG9P.

6 Id. Officials encouraging children to transition—whether

socially or medically—heavily relied on position statements published by medical associations like the World Professional Association for Transgender Health (“WPATH”). See Chloe K. Jones,

The Façade of Medical Consensus: How Medical Associations Prioritize Politics Over Science, 2025 Harv. J.L. & Pub. Pol’y Per

Curiam 4–6 (2025). There is, however, compelling evidence to

suggest these medical associations “often [choose] their positions

. . . to advance policy objectives rather than scientific principles.”

Id. at 6. Indeed, “[r]ecent revelations suggest that WPATH, long

considered a standard bearer in treating pediatric gender dysphoria . . . bases its guidance on insufficient evidence and allows

politics to influence its medical conclusions.” Skrmetti, 605 U.S.

at 543 (Thomas, J., concurring).

7 See Hilary Cass, Independent review of gender identity ser-

vices for children and young people 158–64 (2024),

https://perma.cc/EY2T-W8NM. “Clinical involvement in the decision-making process should include advising on the risks and

benefits of social transition as a planned intervention, referencing best available evidence. This is not a role that can be taken

by staff without appropriate clinical training.” Id. at 164 (emphasis added); Kristine Parks, We Cannot Endorse: Why the Nation’s Plastic Surgeons are Pulling Back on Youth Gender

11

As it turns out, “gender-affirming care” is not so

much “treatment” within the conception of “medicine”

as it is ideological “inculcation.” Medicine is “the science and art dealing with the maintenance of health

and the prevention, alleviation, or cure of disease.” 8

And “disease” is “a condition . . . that impairs normal

functioning.” 9 Thus “gender-affirming care” cannot fit

within the definition of medicine when it includes puberty-blocking drugs, hormonal replacement, mastectomies, and more—“treatments” that strive to impair

one’s normal, biological functioning instead of maintain one’s natural health.

The risks of “gender-affirming care” are profound,

the complications permanent, and the results often

tragic. Suicide, constant paint, tissue necrosis, and

the inability to breastfeed only scratch the surface. 10

Surgery, Fox News (Feb. 9, 2026), https://perma.cc/WZZ8-66Y7

(President of the American Society of Plastic Surgeons “cannot

endorse gender-related surgical interventions in minors” because

“some interventions are irreversible,” carrying “risks, uncertainties, and potential long-term” effects).

8

Medicine, Merriam-Webster.com Dictionary

https://perma.cc/Q6ZA-Z6ED (accessed Sept. 12, 2026).

(2026),

Disease, Merriam-Webster.com Dictionary

https://perma.cc/Q6ZA-Z6ED (accessed Sept. 12, 2026).

(2026),

9

10 See Christina Buttons, The Tragedy of Yarden Silveira, City

Journal (Mar. 12, 2025), https://perma.cc/4AK7-LAE9 (describing a detransitioner’s medical complications, including tissue necrosis, constant pain, and suspected suicide); Ashley J. DiMella,

Detransitioner Chloe Cole Shares Complications After Gender

Procedures: “I Am Grieving”, Fox News (Dec. 18, 2025),

https://perma.cc/4MMS-JBT9 (describing complications from

“gender-affirming care” including the inability to breastfeed).

12

Of course parents should be able to prevent their children from receiving such interventions. See Parham,

442 U.S. at 603. Yet Washington’s law intentionally

boxes them out.

II. Family liberty interests are entrenched in

Anglo-American society and flow from natural order.

Not only are family liberty interests recognized in

law, but the “history and culture of Western civilization reflect a strong tradition of parental concern for

the nurture and upbringing of their children.” Yoder,

406 U.S. at 232. This tradition in Anglo-American society is so entrenched that the “primary role of the

parents in the upbringing of their children is [ ] established beyond debate as an enduring American tradition.” Id. Indeed, “[t]he integrity of the family and

the parents’ inherent right and authority to rear their

own children have been recognized as fundamental

axioms of Anglo-American culture, presupposed by all

our social, political, and legal institutions.” In re J.P.,

648 P.2d 1364, 1373 (Utah 1982) (Oaks, J.); In re Luscier’s Welfare, 524 P.2d 906, 907 (Wash. 1974) (overruled on other grounds) (“The family entity is the core

element upon which modern civilization is founded.”).

Accordingly, the legal “liberty interest in family privacy has its source . . . in intrinsic human rights.”

Smith v. Org. of Foster Fams. For Equal. & Reform,

431 U.S. 816, 845 (1977); see also, In re J.P., 648 P.2d

at 1373 (“This parental right . . . is rooted not in state

or federal statutory or constitutional law, to which it

is logically and chronologically prior, but in nature

and human instinct.”). Our tradition has long recognized that “[t]he parent-child relationship is a sacred,

pre-political bond that preexists” the United States,

13

as well as any local law. Raskin on behalf of JD v.

Dallas Indep. Sch. Dist., 69 F.4th 280, 298 (5th Cir.

2023) (Oldham, J., concurring); see also In re J.P., 648

P.2d at 1373 (“The rights inherent in family relationships . . . are ‘natural,’ ‘intrinsic,’ or ‘prior’ in the sense

that our Constitutions presuppose them, as they presuppose the right to own and dispose of property.”);

Lacher v. Venus, 188 N.W. 613, 617 (Wis. 1922) (“A

natural affection between the parents and offspring .

. . has always been recognized as an inherent, natural

right, for the protection of which . . . our government

is formed.”). Our government recognizes “parental

rights”; it does not create them. Lawson B. Hamilton,

Parent, Child, and State: Regulation in A New Era of

Homeschooling, 51 J.L. & Educ. 45, 69 (2022).

Our Anglo-American legal tradition has always understood this pre-political parental authority as flowing from the natural order of things—especially the

inherent vulnerabilities of children. See Locke, Second Treatise of Government at §§ 55–58, 71 (stating

that parental “jurisdiction” arises from a duty to care

for children during the “imperfect state of childhood,”

and distinguishing parental from political power); H.

Maine, Ancient Law, 163–64 (1st American ed. 1870)

(stating that children “before years of discretion . . .

are subject to extrinsic control on the single ground

that they do not possess the faculty of forming a judgment on their own interests”); Kent, 2 Commentaries

on American Law Lect. 29 (analyzing the rights “of

[p]arent and [c]hild” by describing the “duties of parents to their children” assigned by “the wisdom and

goodness of the great Author of our being, and Father

of Mercies” as the “true foundation of parental

power”). Early American treatises on the rights of

14

parents and children were built from this understanding. See, e.g., The Etna, 8 F. Cas. 803, 806 (D. Me.

1836); see Circular on the Legal Rights of Children,

U.S. Dep’t of the Interior, Bureau of Educ. No. 3-1880

at 24 (1880).

A child’s primary, base unit community is the family. Melissa Moschella, Natural Law, Parental Rights,

and the Defense of “Liberal” Limits on Government, 98

Notre Dame L. Rev. 1559, 1572 (2023). This community is sovereign in its own sphere and mission—the

common good of the family and individuals in it.

Melissa Moschella, Natural Law, Parental Rights and

Education Policy, 59 Am. J. Juris. 197, 212–13 (2014);

Frances Williamson, The Meaning of “Public Meaning”: An Originalist Dilemma Embodied by Mahanoy

Area School District, 46 Harv. J.L. & Pub. Pol’y 257,

283 (2023) (distinguishing between “two spheres of

control”). This higher status is why parents hold the

“primary rights” to direct every aspect of their child’s

life. Gruenke v. Seip, 225 F.3d 290, 307 (3d Cir. 2000).

III. Petitioners have standing.

With a proper understanding of parental rights, it

is easy to see how Washington’s law violates them. By

authorizing children to opt to receive risky treatments

without parental consent, Washington law “obliterate[s]” the parental right to make medical decisions

for a child by “automatically transfer[ring] the power

to make [medical] decisions from the parents to . . .

the state.” Deanda v. Becerra, 96 F.4th 750, 757 (5th

Cir. 2024) (first quote); Parham, 442 U.S. at 603 (second quote). And Washington law deprives parents of

15

the right to “custody” of a runaway child by not informing the parents of the child’s location or returning

the child. Prince, 321 U.S. at 166.

Yet Petitioners were never able to raise their parental-rights claims because the Ninth Circuit held

that they lacked standing. The panel held that Petitioners’ present injury—“hesitance to discipline” their

children for fear that they might run away—was “selfinflicted.” App.14a–15a. It also held that its risk of

future injury—Petitioners’ children running away

and secretly receiving life-altering medical treatment

from the State—was too speculative. App.22a. In doing so, the court misunderstood parental rights and

basic standing law.

“Courts sometimes make standing law more complicated than it needs to be.” Thole v. U.S. Bank N.A.,

590 U.S. 538, 547 (2020). Standing law asks “a basic

question: ‘What’s it to you?’” Bost v. Illinois, 607 U.S.

71, 77 (2026) (quoting A. Scalia, The Doctrine of

Standing as an Essential Element of the Separation of

Powers, 17 Suffolk U. L. Rev. 881, 882 (1983)). To

moms and dads, the right to parent their child as they

see fit is everything, and the Washington law they

challenge abridges that right today. And the loss of

that constitutional right is sufficient to confer standing. Spokeo, Inc. v. Robins, 578 U.S. 330, 339, 340

(2016) (even “intangible injuries” to constitutional

rights are “concrete”).

Indeed, the standing determination is the same

whether Petitioners’ deprivation of rights is viewed in

the abstract or viewed through the lens of the tangible

effects it’s had on Petitioners’ behavior. The fact that

Washington law has “grant[ed] minor children a veto

over their parents’ decisions on gender and gender

16

identity” has sensibly affected how Petitioners talk to,

interact with, and discipline their gender-dysphoric

children. App.40a (VanDyke, J., dissenting); App.71a

¶ 16; App.73a ¶¶ 28–29. This “chilling effect” on Petitioners’ behavior is no less real in the parenting context than it is in the free speech context, for example.

Virginia v. Am. Booksellers Ass’n, 484 U.S. 383, 393

(1988). If the State imposes adverse consequences for

exercising a right, the “predictable” result is for right

holders to forebear. Dep’t of Com. v. New York, 588

U.S. 752, 768 (2019).

Put differently, Petitioners’ present-day injury is

not “self-inflicted”—it was inflicted by Washington

law. The whole point of Washington’s law was to

change parents’ behavior and undermine their ability

to make decisions for their children. See App.95a–96a

(legislator proclaiming that “[w]e must step in” because “there are some unhealthy family dynamics out

there” and “parent[s] need[] another way to speak to

[their] child”). Washington understood that “[p]arents

cannot be free . . . to inculcate their children with traditional views of gender so long as [it] creates a system

facilitating the transition of those children without

their parents’ involvement and against their parent’s

wishes.” App.40a (VanDyke, J., dissenting). In that

sense, parents are the object of the Washington law,

and “there is ordinarily little question that” the object

of a law has standing to challenge it. Lujan v. Def’s of

Wildlife, 504 U.S. 555, 561–62 (1992); Diamond Alternative Energy v. Env’t Prot. Agency, 606 U.S. 100,

114–15 (2025) (explaining that laws often have multiple objects).

While refusing to recognize the actions Petitioners

were taking to prevent their children from running

away to receive “gender-affirming care,” the Ninth

17

Circuit paradoxically further denied standing because

it concluded that Petitioners’ children weren’t close

enough to running away, rendering Petitioners’ future

injury insufficiently concrete. But standing law does

not require Petitioners to live indefinitely between a

rock and a hard place—stuck between keeping their

children safe and pushing their children closer to the

brink of running away so a federal court will remedy

a breach of their parental rights. Pennsylvania v.

West Virginia, 262 U.S. 553, 593 (1923) (“One does not

have to await the consummation of threatened injury

to obtain preventive relief.”).

It bears observation, too, that the Ninth Circuit—

which usually applies standing requirements flexibly

and capaciously—chose this case to embrace an ironfisted version of standing. See App.63a–64a & n.3

(Tung, J., dissenting) (giving examples of “standing

based on future injuries” that were more “attenuated”

than the facts this case); see also City & Cnty. of S.F. v.

USCIS, 981 F.3d 742, 754 (9th Cir. 2020) (forecasting

that “public charge” rule would lead immigrants to unenroll in federal assistance programs and enroll in

state-run programs instead); California v. Azar, 911

F.3d 558, 571–73 (9th Cir. 2018) (predicting that rule

exempting employers from having to provide contraception coverage would lead employers to change their

policies and lead women to seek contraception through

state-run programs). The court’s volte-face suggests either a newfound fastidiousness or a clumsy attempt to

avoid the constitutional question presented here.

Plaintiffs have standing when there is a “substantial risk that [] harm will occur.” New York, 588 U.S.

at 767 (quoting Susan B. Anthony List v. Driehaus,

573 U.S. 149, 158 (2014)). And it is hard to imagine

how Petitioners could have made a stronger showing

18

that there was a “substantial risk” that their children

would avail themselves of Washington law to receive

“gender-affirming care” against Petitioners’ wishes.

Their minor children have gender dysphoria or gender

confusion, and the majority have socially transitioned

at school. App.10a–11a. One set of parents have an

adult child who has called them “transphobic” and

threatened to take the gender-dysphoric minor child

to a “safe place” where the child’s pronouns would be

respected. App.11a. Another set of parents have a

child who has been encouraged by a friend’s family to

run away. App.11a. Another set of parents has a child

who has already run away before. App.11a–12a. And

all that was before the State offered these children a

right to override their parents’ medical decisions.

“The requirements of standing are strict, but they

are not cruel.” App.56a (Tung, J., dissenting). Short

of securing an affidavit from their minor children announcing their plans to run away to seek “gender-affirming care,” it’s unclear what more Petitioners could

possibly do to show a substantial risk of (irreversible)

future harm.

This Court should not require Petitioners’ current

injuries to go unredressed. Nor should it require Petitioners to await severer harms before they can have

their day in court. Petitioners’ parental rights have

already been violated, and this Court should reverse

to restore them.

CONCLUSION

This Court should reverse the judgment below.

19

September 15, 2026

Respectfully submitted,

RAÚL LABRADOR

Attorney General

MICHAEL ZARIAN

Solicitor General

Office of the Idaho

Attorney General

700 W. Jefferson St.

Suite 210

Boise, ID 83720

JAMES UTHMEIER

Attorney General

RYAN D. NEWMAN

Chief Deputy Attorney

General

DAVID M.S. DEWHIRST

Solicitor General

*Counsel of Record

JASON J. MUEHLHOFF

Chief Deputy Solicitor

General

THOMAS F. KELLY, IV

Assistant Solicitor General

Alexzondra Mattson

Solicitor General Fellow

Office of the Florida

Attorney General

PL-01, The Capitol

Tallahassee, FL 32399

david.dewhirst@

myfloridalegal.com

Counsel for Amici Curiae

20

ADDITIONAL SIGNATORIES

STEVE MARSHALL

Attorney General

State of Alabama

LYNN FITCH

Attorney General

State of Mississippi

STEPHEN J. COX

Attorney General

State of Alaska

CATHERINE L. HANAWAY

Attorney General

State of Missouri

TIM GRIFFIN

Attorney General

State of Arkansas

AUSTIN KNUDSEN

Attorney General

State of Montana

CHRIS CARR

Attorney General

State of Georgia

MICHAEL T. HILGERS

Attorney General

State of Nebraska

BRENNA BIRD

Attorney General

State of Iowa

DREW H. WRIGLEY

Attorney General

State of North Dakota

KRIS KOBACH

Attorney General

State of Kansas

GENTNER DRUMMOND

Attorney General

State of Oklahoma

RUSSELL COLEMAN

Attorney General

State of Kentucky

ALAN WILSON

Attorney General

State of South Carolina

LIZ MURRILL

Attorney General

State of Louisiana

MARTY JACKLEY

Attorney General

State of South Dakota

21

JONATHAN SKRMETTI

Attorney General

State of Tennessee

JOHN B. MCCUSKEY

Attorney General

State of West Virginia

KEN PAXTON

Attorney General

State of Texas

KEITH G. KAUTZ

Attorney General

State of Wyoming