OPINION

GRABER, Circuit Judge:

The California legislature enacted Senate Bill 1172 to ban state-licensed mental health providers from engaging in "sexual orientation change efforts" ("SOCE") with patients under 18 years of age. Two groups of plaintiffs sought to enjoin enforcement of the law, arguing that SB 1172 violates the First Amendment and infringes on several other constitutional rights.

In Welch v. Brown, No. 13-15023, the district court ruled that Plaintiffs were likely to succeed on the merits of their First Amendment claim and that the balance of the other preliminary-injunction factors tipped in their favor; thus, the court granted a preliminary injunction. In Pickup v. Brown, No. 12-17681, the district court ruled that Plaintiffs were unlikely to succeed on the merits of any of their claims and denied preliminary relief. The losing parties timely appealed. We address both appeals in this opinion.

Although we generally review for abuse of discretion a district court's decision to grant or deny a preliminary injunction, we may undertake plenary review of the issues if a district court's ruling "`rests solely on a premise as to the applicable rule of law, and the facts are established or of no controlling relevance.'" Gorbach v. Reno, 219 F.3d 1087, 1091 (9th Cir.2000) (en banc) (quoting Thornburgh v. Am. Coll. of Obstetricians & Gynecologists, 476 U.S. 747, 755-57, 106 S.Ct. 2169, 90 L.Ed.2d 779 (1986)). Because those conditions are met here, we undertake plenary review and hold that SB 1172, as a regulation of professional conduct, does not violate the free speech rights of SOCE practitioners or minor patients, is neither vague nor overbroad, and does not violate parents' fundamental rights. Accordingly, we reverse the order granting preliminary relief in Welch and affirm the denial of preliminary relief in Pickup.

FACTUAL AND PROCEDURAL BACKGROUND

A. Sexual Orientation Change Efforts ("SOCE")

SOCE, sometimes called reparative or conversion therapy, began at a time when the medical and psychological community considered homosexuality an illness. SOCE encompasses a variety of methods, including both aversive and non-aversive treatments, that share the goal of changing an individual's sexual orientation from homosexual to heterosexual. In the past, aversive treatments included inducing nausea, vomiting, or paralysis; providing electric shocks; or having an individual snap an elastic band around the wrist when aroused by same-sex erotic images or thoughts. Even more drastic methods, such as castration, have been used. Today, some non-aversive treatments use assertiveness and affection training with physical and social reinforcement to increase other-sex sexual behaviors. Other non-aversive treatments attempt "to change gay men's and lesbians' thought patterns by reframing desires, redirecting thoughts, or using hypnosis, with the goal of changing sexual arousal, behavior, and orientation." American Psychological Association, Appropriate Therapeutic Responses to Sexual Orientation 22 (2009). The plaintiff mental health providers in these cases use only non-aversive treatments.

In 1973, homosexuality was removed from the Diagnostic and Statistical Manual of Mental Disorders. Shortly thereafter the American Psychological Association declared that homosexuality is not an illness. Other major mental health associations followed suit. Subsequently, many mental health providers began questioning and rejecting the efficacy and appropriateness of SOCE therapy. Currently, mainstream mental health professional associations support affirmative therapeutic approaches to sexual orientation that focus on coping with the effects of stress and stigma. But a small number of mental health providers continue to practice, and advocate for, SOCE therapy.

B. Senate Bill 1172

Senate Bill 1172 defines SOCE as "any practices by mental health providers[1] that seek to change an individual's sexual orientation[,] ... includ[ing] efforts to change behaviors or gender expressions, or to eliminate or reduce sexual or romantic attractions or feelings toward individuals of the same sex." Cal. Bus. & Prof. Code § 865(b)(1). SOCE, however,

Id. § 865(b)(2). A licensed mental health provider's use of SOCE on a patient under 18 years of age is "considered unprofessional conduct," which will subject that provider to "discipline by the licensing entity for that mental health provider." Id. § 865.2.

Importantly, SB 1172 does not do any of the following:

Instead, SB 1172 does just one thing: it requires licensed mental health providers in California who wish to engage in "practices... that seek to change a [minor's] sexual orientation" either to wait until the minor turns 18 or be subject to professional discipline. Thus, SB 1172 regulates the provision of medical treatment, but leaves mental health providers free to discuss or recommend treatment and to express their views on any topic.

The legislature's stated purpose in enacting SB 1172 was to "protect[] the physical and psychological well-being of minors, including lesbian, gay, bisexual, and transgender youth, and [to] protect[] its minors against exposure to serious harms caused by sexual orientation change efforts." 2012 Cal. Legis. Serv. ch. 835, § 1(n). The legislature relied on the well documented, prevailing opinion of the medical and psychological community that SOCE has not been shown to be effective and that it creates a potential risk of serious harm to those who experience it. Specifically, the legislature relied on position statements, articles, and reports published by the following organizations: the American Psychological Association, the American Psychiatric Association, the American School Counselor Association, the American Academy of Pediatrics, the American Medical Association, the National Association of Social Workers, the American Counseling Association, the American Psychoanalytic Association, the American Academy of Child and Adolescent Psychiatry, and the Pan American Health Organization.

In particular, the legislature relied on a report created by a Task Force of the American Psychological Association. That report resulted from a systematic review of the scientific literature on SOCE. Methodological problems with some of the reviewed studies limited the conclusions that the Task Force could draw. Nevertheless, the report concluded that SOCE practitioners have not demonstrated the efficacy of SOCE and that anecdotal reports of harm raise serious concerns about the safety of SOCE.

C. Procedural History

Plaintiffs in Welch include two SOCE practitioners and an aspiring SOCE practitioner. Plaintiffs in Pickup include SOCE practitioners, organizations that advocate SOCE, children undergoing SOCE, and their parents. All sought a declaratory judgment that SB 1172 is unconstitutional and asked for injunctive relief to prohibit enforcement of the law.2

In Welch, Plaintiffs moved for preliminary injunctive relief, arguing that SB 1172 violates their free speech and privacy rights. They also argued that the law violates the religion clauses and is unconstitutionally vague and overbroad under the First Amendment.

The Welch court held that SB 1172 is subject to strict scrutiny because it would restrict the content of speech and suppress the expression of particular viewpoints. It reasoned that the fact that the law is a professional regulation does not change the level of scrutiny. The court granted preliminary relief because it determined that the state was unlikely to satisfy strict scrutiny, Plaintiffs would suffer irreparable harm in the absence of an injunction, the balance of the equities tipped in their favor, and the injunction was in the public interest. Because the district court granted relief on their free speech claim, it did not reach Plaintiffs' other constitutional challenges.3

In Pickup, Plaintiffs moved for preliminary injunctive relief, arguing that SB 1172 violates the First and Fourteenth Amendments by infringing on SOCE practitioners' right to free speech, minors' right to receive information, and parents' right to direct the upbringing of their children. They also argued that SB 1172 is unconstitutionally vague.

The Pickup court denied Plaintiffs' motion because it determined that they were unlikely to prevail on the merits of any of their claims. It reasoned that, because the plain text of SB 1172 bars only treatment, but not discussions about treatment, the law regulates primarily conduct rather than speech. Applying the rational basis test, the court ruled that Plaintiffs were unlikely to show a violation of the SOCE practitioners' free speech rights or the minors' right to receive information. As for vagueness, the court ruled that the text of the statute is clear enough to put mental health providers on notice of what is prohibited. Finally, the court ruled that SB 1172 does not implicate parents' right to control the upbringing of their children because that right does not encompass the right to choose a specific mental health treatment that the state has reasonably deemed harmful to minors.

DISCUSSION

A. Free Speech Rights

At the outset, we must decide whether the First Amendment requires heightened scrutiny of SB 1172. As explained below, we hold that it does not.

The first step in our analysis is to determine whether SB 1172 is a regulation of conduct or speech. Two of our cases guide our decision: National Association for the Advancement of Psychoanalysis v. California Board of Psychology, 228 F.3d 1043 (9th Cir.2000) ("NAAP"), and Conant v. Walters, 309 F.3d 629 (9th Cir.2002).

In NAAP, 228 F.3d at 1053, psychoanalysts who were not licensed in California brought a First Amendment challenge to California's licensing scheme for mental health providers. The licensing scheme required that persons who provide psychological services to the public for a fee obtain a license, which in turn required particular educational and experiential credentials. Id. at 1047. The plaintiffs alleged that the licensing scheme violated their First Amendment right to freedom of speech because the license examination tested only certain psychological theories and required certain training; plaintiffs had studied and trained under different psychoanalytic theories. Id. at 1055. We were equivocal about whether, and to what extent, the licensing scheme in NAAP implicated any free speech concerns. Id. at 1053 ("We conclude that, even if a speech interest is implicated, California's licensing scheme passes First Amendment scrutiny." (emphasis added)); id. at 1056 ("Although some speech interest may be implicated, California's content-neutral mental health licensing scheme is a valid exercise of its police power...." (emphasis added)). We reasoned that prohibitions of conduct have "`never been deemed an abridgement of freedom of speech ... merely because the conduct was in part initiated, evidenced, or carried out by means of language.'" See id. at 1053 (ellipsis in original) (quoting Giboney v. Empire Storage & Ice Co., 336 U.S. 490, 502, 69 S.Ct. 684, 93 L.Ed. 834 (1949)). And, importantly, we specifically rejected the argument that "because psychoanalysis is the `talking cure,' it deserves special First Amendment protection because it is `pure speech.'" Id. at 1054. We reasoned: "[T]he key component of psychoanalysis is the treatment of emotional suffering and depression, not speech. That psychoanalysts employ speech to treat their clients does not entitle them, or their profession, to special First Amendment protection." Id. (internal quotation marks and ellipsis omitted).

Nevertheless, we concluded that the "communication that occurs during psychoanalysis is entitled to constitutional protection, but it is not immune from regulation." Id. But we neither decided how much protection that communication should receive nor considered whether the level of protection might vary depending on the function of the communication. Given California's strong interest in regulating mental health, we held that the licensing scheme at issue in NAAP was a valid exercise of its police power. Id. at 1054-55.

We went on to conclude that, even if the licensing scheme in NAAP regulated speech, it did not trigger strict scrutiny because it was both content neutral and viewpoint neutral. Id. at 1055. We reasoned that the licensing laws did not "dictate what can be said between psychologists and patients during treatment." Id. Further, we observed that those laws were "not adopted because of any disagreement with psychoanalytical theories" but for "the important purpose of protecting public health, safety, and welfare." Id. at 1056 (internal quotation marks omitted). We again concluded that the laws were a valid exercise of California's police power. Id.

In Conant, 309 F.3d at 633-34, we affirmed a district court's order granting a permanent injunction that prevented the federal government from revoking a doctor's DEA registration or initiating an investigation if he or she recommended medical marijuana. The federal government had adopted a policy that a doctor's "recommendation" of marijuana would lead to revocation of his or her license. Id. at 632. But the government was "unable to articulate exactly what speech [the policy] proscribed, describing it only in terms of speech the patient believes to be a recommendation of marijuana." Id. at 639. Nevertheless, the demarcation between conduct and speech in Conant was clear. The policy prohibited doctors from prescribing or distributing marijuana, and neither we nor the parties disputed the government's authority to prohibit doctors from treating patients with marijuana. Id. at 632, 635-36. Further, the parties agreed that "revocation of a license was not authorized where a doctor merely discussed the pros and cons of marijuana use." Id. at 634 (emphasis added).

We ruled that the policy against merely "recommending" marijuana was both content- and viewpoint-based. Id. at 637. It was content-based because it covered only doctor-patient speech "that include[d] discussions of the medical use of marijuana," and it was viewpoint-based because it "condemn[ed] expression of a particular viewpoint, i.e., that medical marijuana would likely help a specific patient." Id. We held that the policy did not withstand heightened First Amendment scrutiny because it lacked "the requisite narrow specificity" and left "doctors and patients no security for free discussion." Id. at 639 (internal quotation marks omitted).

We distill the following relevant principles from NAAP and Conant: (1) doctor-patient communications about medical treatment receive substantial First Amendment protection, but the government has more leeway to regulate the conduct necessary to administering treatment itself; (2) psychotherapists are not entitled to special First Amendment protection merely because the mechanism used to deliver mental health treatment is the spoken word; and (3) nevertheless, communication that occurs during psychotherapy does receive some constitutional protection, but it is not immune from regulation.

Because those principles, standing alone, do not tell us whether or how the First Amendment applies to the regulation of specific mental health treatments, we must go on to consider more generally the First Amendment rights of professionals, such as doctors and mental health providers. In determining whether SB 1172 is a regulation of speech or conduct, we find it helpful to view this issue along a continuum.

At one end of the continuum, where a professional is engaged in a public dialogue, First Amendment protection is at its greatest. Thus, for example, a doctor who publicly advocates a treatment that the medical establishment considers outside the mainstream, or even dangerous, is entitled to robust protection under the First Amendment — just as any person is — even though the state has the power to regulate medicine. See Lowe v. SEC, 472 U.S. 181, 232, 105 S.Ct. 2557, 86 L.Ed.2d 130 (1985) (White, J., concurring) ("Where the personal nexus between professional and client does not exist, and a speaker does not purport to be exercising judgment on behalf of any particular individual with whose circumstances he is directly acquainted, government regulation ceases to function as legitimate regulation of professional practice with only incidental impact on speech; it becomes regulation of speaking or publishing as such, subject to the First Amendment's command that `Congress shall make no law ... abridging the freedom of speech, or of the press.'"); Robert Post, Informed Consent to Abortion: A First Amendment Analysis of Compelled Physician Speech, 2007 U. Ill. L.Rev. 939, 949 (2007) ("When a physician speaks to the public, his opinions cannot be censored and suppressed, even if they are at odds with preponderant opinion within the medical establishment."); cf. Bailey v. Huggins Diagnostic & Rehab. Ctr., Inc., 952 P.2d 768, 773 (Colo.Ct.App.1997) (holding that the First Amendment does not permit a court to hold a dentist liable for statements published in a book or made during a news program, even when those statements are contrary to the opinion of the medical establishment). That principle makes sense because communicating to the public on matters of public concern lies at the core of First Amendment values. See, e.g., Snyder v. Phelps, ___ U.S. ___, 131 S.Ct. 1207, 1215, 179 L.Ed.2d 172 (2011) ("Speech on matters of public concern is at the heart of the First Amendment's protection." (internal quotation markets, brackets, and ellipsis omitted)). Thus, outside the doctor-patient relationship, doctors are constitutionally equivalent to soapbox orators and pamphleteers, and their speech receives robust protection under the First Amendment.

At the midpoint of the continuum, within the confines of a professional relationship, First Amendment protection of a professional's speech is somewhat diminished. For example, in Planned Parenthood of Southeastern Pennsylvania v. Casey, 505 U.S. 833, 884, 112 S.Ct. 2791, 120 L.Ed.2d 674 (1992), the plurality upheld a requirement that doctors disclose truthful, nonmisleading information to patients about certain risks of abortion:

(Citations omitted; emphasis added.) Outside the professional relationship, such a requirement would almost certainly be considered impermissible compelled speech. Cf. Wooley v. Maynard, 430 U.S. 705, 717 [97 S.Ct. 1428, 51 L.Ed.2d 752] (1977) (holding that a state could not require a person to display the state motto on his or her license plate).

Moreover, doctors are routinely held liable for giving negligent medical advice to their patients, without serious suggestion that the First Amendment protects their right to give advice that is not consistent with the accepted standard of care. A doctor "may not counsel a patient to rely on quack medicine. The First Amendment would not prohibit the doctor's loss of license for doing so." Conant v. McCaffrey, No. C 97-00139 WHA, 2000 WL 1281174, at *13 (N.D.Cal. Sept. 7, 2000) (order) (unpublished); see also Shea v. Bd. of Med. Exam'rs, 81 Cal.App.3d 564, 146 Cal.Rptr. 653, 662 (1978) ("The state's obligation and power to protect its citizens by regulation of the professional conduct of its health practitioners is well settled.... [T]he First Amendment ... does not insulate the verbal charlatan from responsibility for his conduct; nor does it impede the State in the proper exercise of its regulatory functions." (citations omitted)); cf. Post, 2007 U. Ill. L.Rev. at 949 ("[W]hen a physician speaks to a patient in the course of medical treatment, his opinions are normally regulated on the theory that they are inseparable from the practice of medicine."). And a lawyer may be disciplined for divulging confidences of his client, even though such disclosure is pure speech. See, e.g., In re Isaacson, State Bar Court of California, Case No. 08-O-10684, 2012 WL 6589666, at *4-5 (Dec. 6, 2012) (unpublished) (noting prior suspension of bar license for failure to preserve client confidences). Thus, the First Amendment tolerates a substantial amount of speech regulation within the professional-client relationship that it would not tolerate outside of it. And that toleration makes sense: When professionals, by means of their state-issued licenses, form relationships with clients, the purpose of those relationships is to advance the welfare of the clients, rather than to contribute to public debate. Cf. Lowe, 472 U.S. at 232, 105 S.Ct. 2557 (White, J., concurring) ("One who takes the affairs of a client personally in hand and purports to exercise judgment on behalf of the client in the light of the client's individual needs and circumstances is properly viewed as engaging in the practice of a profession.").

At the other end of the continuum, and where we conclude that SB 1172 lands, is the regulation of professional conduct, where the state's power is great, even though such regulation may have an incidental effect on speech. See id. ("Just as offer and acceptance are communications incidental to the regulable transaction called a contract, the professional's speech is incidental to the conduct of the profession."). Most, if not all, medical treatment requires speech, but that fact does not give rise to a First Amendment claim when the state bans a particular treatment. When a drug is banned, for example, a doctor who treats patients with that drug does not have a First Amendment right to speak the words necessary to provide or administer the banned drug. Cf. Conant, 309 F.3d at 634-35 (noting the government's authority to ban prescription of marijuana). Were it otherwise, then any prohibition of a particular medical treatment would raise First Amendment concerns because of its incidental effect on speech. Such an application of the First Amendment would restrict unduly the states' power to regulate the medical profession and would be inconsistent with the principle that "it has never been deemed an abridgement of freedom of speech or press to make a course of conduct illegal merely because the conduct was in part initiated, evidenced, or carried out by means of language, either spoken, written, or printed." Giboney, 336 U.S. at 502, 69 S.Ct. 684.

Senate Bill 1172 regulates conduct. It bans a form of medical treatment for minors; it does nothing to prevent licensed therapists from discussing the pros and cons of SOCE with their patients. Senate Bill 1172 merely prohibits licensed mental health providers from engaging in SOCE with minors. It is the limited reach of SB 1172 that distinguishes the present cases from Conant, in which the government's policy prohibited speech wholly apart from the actual provision of treatment. Under its police power, California has authority to prohibit licensed mental health providers from administering therapies that the legislature has deemed harmful and, under Giboney, 336 U.S. at 502, 69 S.Ct. 684, the fact that speech may be used to carry out those therapies does not turn the prohibitions of conduct into prohibitions of speech. In fact, the Welch Plaintiffs concede that the state has the power to ban aversive types of SOCE. And we reject the position of the Pickup Plaintiffs — asserted during oral argument — that even a ban on aversive types of SOCE requires heightened scrutiny because of the incidental effect on speech.5 Here, unlike in Conant, 309 F.3d at 639, the law allows discussions about treatment, recommendations to obtain treatment, and expressions of opinions about SOCE and homosexuality.

We further conclude that the First Amendment does not prevent a state from regulating treatment even when that treatment is performed through speech alone. As we have already held in NAAP, talk therapy does not receive special First Amendment protection merely because it is administered through speech. 228 F.3d at 1054. That holding rested on the understanding of talk therapy as "the treatment of emotional suffering and depression, not speech." Id. (internal quotation marks omitted) (first emphasis added). Thus, under NAAP, to the extent that talk therapy implicates speech, it stands on the same First Amendment footing as other forms of medical or mental health treatment. Senate Bill 1172 is subject to deferential review just as are other regulations of the practice of medicine.

Our conclusion is consistent with NAAP's statement that "communication that occurs during psychoanalysis is entitled to constitutional protection, but it is not immune from regulation." Id. Certainly, under Conant, content- or viewpoint-based regulation of communication about treatment must be closely scrutinized. But a regulation of only treatment itself — whether physical medicine or mental health treatment — implicates free speech interests only incidentally, if at all. To read NAAP otherwise would contradict its holding that talk therapy is not entitled to "special First Amendment protection," and it would, in fact, make talk therapy virtually "immune from regulation." Id.

Nor does NAAP's discussion of content and viewpoint discrimination change our conclusion. There, we used both a belt and suspenders. In addition to holding that the licensing scheme at issue was a permissible regulation of conduct, we reasoned that even if California's licensing requirements implicated First Amendment interests, the requirements did not discriminate on the basis of content or viewpoint. Id. at 1053, 1055-56. But here, SB 1172 regulates only treatment, and nothing in NAAP requires us to analyze a regulation of treatment in terms of content and viewpoint discrimination.6

Because SB 1172 regulates only treatment, while leaving mental health providers free to discuss and recommend, or recommend against, SOCE, we conclude that any effect it may have on free speech interests is merely incidental. Therefore, we hold that SB 1172 is subject to only rational basis review and must be upheld if it "bear[s] ... a rational relationship to a legitimate state interest."7 Id. at 1049.

According to the statute, SB 1172 advances California's interest in "protecting the physical and psychological well-being of minors, including lesbian, gay, bisexual and transgender youth, and in protecting its minors against exposure to serious harms caused by sexual orientation change efforts." 2012 Cal. Legis. Serv. ch. 835, § 1(n). Without a doubt, protecting the well-being of minors is a legitimate state interest. And we need not decide whether SOCE actually causes "serious harms"; it is enough that it could "reasonably be conceived to be true by the governmental decisionmaker." NAAP, 228 F.3d at 1050 (internal quotation marks omitted).

The record demonstrates that the legislature acted rationally when it decided to protect the well-being of minors by prohibiting mental health providers from using SOCE on persons under 18.8 The legislature relied on the report of the Task Force of the American Psychological Association, which concluded that SOCE has not been demonstrated to be effective and that there have been anecdotal reports of harm, including depression, suicidal thoughts or actions, and substance abuse. The legislature also relied on the opinions of many other professional organizations. Each of those organizations opposed the use of SOCE, concluding, among other things, that homosexuality is not an illness and does not require treatment (American School Counselor Association), SOCE therapy can provoke guilt and anxiety (American Academy of Pediatrics), it may be harmful (National Association of Social Workers), and it may contribute to an enduring sense of stigma and self-criticism (American Psychoanalytic Association). Although the legislature also had before it some evidence that SOCE is safe and effective, the overwhelming consensus was that SOCE was harmful and ineffective. On this record, we have no trouble concluding that the legislature acted rationally by relying on that consensus.

Plaintiffs argue that the legislature acted irrationally when it banned SOCE for minors because there is a lack of scientifically credible proof of harm. But, under rational basis review, "[w]e ask only whether there are plausible reasons for [the legislature's] action, and if there are, our inquiry is at an end." Romero-Ochoa v. Holder, 712 F.3d 1328, 1331 (9th Cir. 2013) (internal quotation marks omitted).

Therefore, we hold that SB 1172 is rationally related to the legitimate government interest of protecting the well-being of minors.9

B. Expressive Association

We also reject the Pickup Plaintiffs' argument that SB 1172 implicates their right to freedom of association because the First Amendment protects their "choices to enter into and maintain the intimate human relationships between counselors and clients."10

First, SB 1172 does not prevent mental health providers and clients from entering into and maintaining therapeutic relationships. It prohibits only "practices ... that seek to change an individual's sexual orientation." Cal. Bus. & Prof.Code § 865(b)(1). Therapists are free, but not obligated, to provide therapeutic services, as long as they do not "seek to change sexual orientation."

Moreover, the therapist-client relationship is not the type of relationship that the freedom of association has been held to protect. The Supreme Court's decisions "have referred to constitutionally protected `freedom of association' in two distinct senses." Roberts v. U.S. Jaycees, 468 U.S. 609, 617, 104 S.Ct. 3244, 82 L.Ed.2d 462 (1984). The first type of protected association concerns "intimate human relationships," which are implicated in personal decisions about marriage, childbirth, raising children, cohabiting with relatives, and the like. Id. at 617-19, 104 S.Ct. 3244. That type of freedom of association "receives protection as a fundamental element of personal liberty." Id. at 618, 104 S.Ct. 3244. The second type protects association "for the purpose of engaging in those activities protected by the First Amendment — speech, assembly, petition for the redress of grievances, and the exercise of religion." Id. at 618, 104 S.Ct. 3244. Plaintiffs in Pickup claim an infringement of only the first type of freedom of association.

Although we have not specifically addressed the therapist-client relationship in terms of freedom of association, we have explained why the therapist-client relationship is not protected by the Due Process Clause of the Fourteenth Amendment: "The relationship between a client and psychoanalyst lasts only as long as the client is willing to pay the fee. Even if analysts and clients meet regularly and clients reveal secrets and emotional thoughts to their analysts, these relationships simply do not rise to the level of a fundamental right." NAAP, 228 F.3d at 1050 (internal quotation marks and citation omitted). Because the type of associational protection that the Pickup Plaintiffs claim is rooted in "personal liberty," U.S. Jaycees, 468 U.S. at 618, 104 S.Ct. 3244, and because we have already determined that the therapist-client relationship does not "implicate the fundamental rights associated with ... close-knit relationships," NAAP, 228 F.3d at 1050, we conclude that the freedom of association also does not encompass the therapist-client relationship.

C. Vagueness

We next hold that SB 1172 is not void for vagueness.

"It is a basic principle of due process that an enactment is void for vagueness if its prohibitions are not clearly defined." Grayned v. City of Rockford, 408 U.S. 104, 108, 92 S.Ct. 2294, 33 L.Ed.2d 222 (1972). Nevertheless, "perfect clarity and precise guidance have never been required even of regulations that restrict expressive activity." Ward v. Rock Against Racism, 491 U.S. 781, 794, 109 S.Ct. 2746, 105 L.Ed.2d 661 (1989). "[U]ncertainty at a statute's margins will not warrant facial invalidation if it is clear what the statute proscribes `in the vast majority of its intended applications.'" Cal. Teachers Ass'n v. State Bd. of Educ., 271 F.3d 1141, 1151 (9th Cir.2001) (quoting Hill v. Colorado, 530 U.S. 703, 733, 120 S.Ct. 2480, 147 L.Ed.2d 597 (2000)). "A defendant is deemed to have fair notice of an offense if a reasonable person of ordinary intelligence would understand that his or her conduct is prohibited by the law in question." United States v. Weitzenhoff, 35 F.3d 1275, 1289 (9th Cir.1994) (internal quotation marks omitted). But, "if the statutory prohibition involves conduct of a select group of persons having specialized knowledge, and the challenged phraseology is indigenous to the idiom of that class, the standard is lowered and a court may uphold a statute which uses words or phrases having a technical or other special meaning, well enough known to enable those within its reach to correctly apply them." Id. (internal quotation marks omitted).

Although the Pickup Plaintiffs argue that they cannot ascertain where the line is between what is prohibited and what is permitted — for example, they wonder whether the mere dissemination of information about SOCE would subject them to discipline — the text of SB 1172 is clear to a reasonable person. It prohibits "mental health providers" from engaging in "practices" that "seek to change" a minor "patient['s]" sexual orientation. Cal. Bus. & Prof.Code §§ 865-865.1. A reasonable person would understand the statute to prohibit only mental health treatment, including psychotherapy, that aims to alter a minor patient's sexual orientation. Although Plaintiffs present various hypothetical situations to support their vagueness challenge, the Supreme Court has held that "speculation about possible vagueness in hypothetical situations not before the Court will not support a facial attack on a statute when it is surely valid in the vast majority of its intended applications." Hill, 530 U.S. at 733, 120 S.Ct. 2480 (internal quotation marks omitted).

Moreover, considering that SB 1172 regulates licensed mental health providers, who constitute "a select group of persons having specialized knowledge," the standard for clarity is lower. Weitzenhoff, 35 F.3d at 1289. Indeed, it is hard to understand how therapists who identify themselves as SOCE practitioners can credibly argue that they do not understand what the ban on SOCE prohibits.

Neither is the term "sexual orientation" vague. Its meaning is clear enough to a reasonable person and should be even more apparent to mental health providers. In fact, several provisions in the California Code — though not SB 1172 itself — provide a simple definition: "heterosexuality, homosexuality, or bisexuality." Cal. Educ. Code §§ 212.6, 66262.7;Cal. Gov't Code § 12926®; Cal.Penal Code §§ 422.56(h), 11410(b)(7). Moreover, courts have repeatedly rejected vagueness challenges that rest on the term "sexual orientation." E.g., United States v. Jenkins, 909 F.Supp.2d 758, 778-79 (E.D.Ky.2012); Hyman v. City of Louisville, 132 F.Supp.2d 528, 546 (W.D.Ky.2001), vacated on other grounds, 53 Fed.Appx. 740 (6th Cir.2002) (unpublished).

D. Overbreadth

We further hold that SB 1172 is not overbroad.11

Overbreadth doctrine permits the facial invalidation of laws that prohibit "a substantial amount of constitutionally protected speech." City of Houston v. Hill, 482 U.S. 451, 466, 107 S.Ct. 2502, 96 L.Ed.2d 398 (1987). "[T]he mere fact that one can conceive of some impermissible applications of a statute is not sufficient to render it susceptible to an overbreadth challenge." Members of City Council v. Taxpayers for Vincent, 466 U.S. 789, 800, 104 S.Ct. 2118, 80 L.Ed.2d 772 (1984). Rather, "particularly where conduct and not merely speech is involved, ... the overbreadth of a statute must not only be real, but substantial as well, judged in relation to the statute's plainly legitimate sweep." Broadrick v. Oklahoma, 413 U.S. 601, 615, 93 S.Ct. 2908, 37 L.Ed.2d 830 (1973).

Senate Bill 1172's plainly legitimate sweep includes the prohibition of SOCE techniques such as inducing vomiting or paralysis, administering electric shocks, and performing castrations. And, as explained above, it also includes SOCE techniques carried out solely through words. As with any ban on a particular medical treatment, there may be an incidental effect on speech. Any incidental effect, however, is small in comparison with the "plainly legitimate sweep" of the ban. Broadrick, 413 U.S. at 615, 93 S.Ct. 2908.

Thus, SB 1172 is not overbroad.

E. Parents' Fundamental Rights

The Pickup Plaintiffs also argue that SB 1172 infringes on their fundamental parental right to make important medical decisions for their children. The state does not dispute that parents have a fundamental right to raise their children as they see fit, but argues that Plaintiffs "cannot compel the State to permit licensed mental health [professionals] to engage in unsafe practices, and cannot dictate the prevailing standard of care in California based on their own views." Because Plaintiffs argue for an affirmative right to access SOCE therapy from licensed mental health providers, the precise question at issue is whether parents' fundamental rights include the right to choose for their children a particular type of provider for a particular medical or mental health treatment that the state has deemed harmful. See Washington v. Glucksberg, 521 U.S. 702, 720-21, 117 S.Ct. 2258, 138 L.Ed.2d 772 (1997) (holding that courts should precisely define purported substantive due process rights to direct and restrain exposition of the Due Process Clause).

Parents have a constitutionally protected right to make decisions regarding the care, custody, and control of their children, but that right is "not without limitations." Fields v. Palmdale Sch. Dist., 427 F.3d 1197, 1204 (9th Cir.2005). States may require school attendance and mandatory school uniforms, and they may impose curfew laws applicable only to minors. See id. at 1204-05 (collecting cases demonstrating the "wide variety of state actions that intrude upon the liberty interest of parents in controlling the upbringing and education of their children"). In the health arena, states may require the compulsory vaccination of children (subject to some exceptions), see Prince v. Massachusetts, 321 U.S. 158, 166, 64 S.Ct. 438, 88 L.Ed. 645 (1944), and states may intervene when a parent refuses necessary medical care for a child, see Jehovah's Witnesses v. King Cnty. Hosp., 278 F.Supp. 488, 504 (W.D.Wash.1967) (three judge panel) (per curiam), aff'd, 390 U.S. 598, 88 S.Ct. 1260, 20 L.Ed.2d 158 (1968) (per curiam). "[A] state is not without constitutional control over parental discretion in dealing with children when their physical or mental health is jeopardized." Parham v. J.R., 442 U.S. 584, 603, 99 S.Ct. 2493, 61 L.Ed.2d 101 (1979).

We are unaware of any case that specifically addresses whether a parent's fundamental rights encompass the right to choose for a child a particular type of provider for a particular treatment that the state has deemed harmful, but courts that have considered whether patients have the right to choose specific treatments for themselves have concluded that they do not. For example, we have held that "substantive due process rights do not extend to the choice of type of treatment or of a particular health care provider." NAAP, 228 F.3d at 1050. Thus, we concluded that "there is no fundamental right to choose a mental health professional with specific training." Id. The Seventh Circuit has also held that "a patient does not have a constitutional right to obtain a particular type of treatment or to obtain treatment from a particular provider if the government has reasonably prohibited that type of treatment or provider." Mitchell v. Clayton, 995 F.2d 772, 775 (7th Cir.1993). Moreover, courts have held that there is no substantive due process right to obtain drugs that the FDA has not approved, Carnohan v. United States, 616 F.2d 1120, 1122 (9th Cir.1980) (per curiam), even when those drugs are sought by terminally ill cancer patients, see Rutherford v. United States, 616 F.2d 455, 457 (10th Cir.1980) ("It is apparent in the context with which we are here concerned that the decision by the patient whether to have a treatment or not is a protected right, but his selection of a particular treatment, or at least a medication, is within the area of governmental interest in protecting public health."). Those cases cut against recognizing the right that Plaintiffs assert; it would be odd if parents had a substantive due process right to choose specific treatments for their children — treatments that reasonably have been deemed harmful by the state — but not for themselves. All the more anomalous because the Supreme Court has recognized that the state has greater power over children than over adults. Prince, 321 U.S. at 170, 64 S.Ct. 438 (stating that "the power of the state to control the conduct of children reaches beyond the scope of its authority over adults").

Further, our decision in Fields counsels against recognizing the right that Plaintiffs assert. In that case, parents of school children argued that a school violated their parental rights when it administered to students a survey that contained several questions about sex. Fields, 427 F.3d at 1203. We rejected that argument, holding that, although parents have the right to inform their children about sex when and as they choose, they do not have the right to "compel public schools to follow their own idiosyncratic views as to what information the schools may dispense." Id. at 1206. Similarly, here, to recognize the right Plaintiffs assert would be to compel the California legislature, in shaping its regulation of mental health providers, to accept Plaintiffs' personal views of what therapy is safe and effective for minors. The aforementioned cases lead us to conclude that the fundamental rights of parents do not include the right to choose a specific type of provider for a specific medical or mental health treatment that the state has reasonably deemed harmful.

Therefore, SB 1172 does not infringe on the fundamental rights of parents.

CONCLUSION

Senate Bill 1172 survives the constitutional challenges presented here. Accordingly, the order granting preliminary relief in Welch, No. 13-15023, is REVERSED, and the order denying preliminary relief in Pickup, No. 12-17681, is AFFIRMED. We remand both cases for further proceedings consistent with this opinion.