I respectfully dissent.
The majority invalidates the Legislature’s decision to require mandatory lifetime sex offender registration for persons who engage in unlawful voluntary oral copulation with a minor who is 16 or 17 years of age, because those who engage in unlawful voluntary intercourse with a same-age minor are subject to discretionary sex offender registration. But as any teenager or adult knows, intercourse is distinct from oral copulation, involving a wholly different sexual act that, unlike oral copulation, may result in pregnancy and the birth of a child. Given this significant difference in the potential real-life consequences of the two acts, the Legislature reasonably could decide that different registration schemes for the two groups of offenders are appropriate as a matter of public policy. Thus, while both offenses involve voluntary sexual conduct with minors, the Legislature chose to leave the imposition of sex offender registration to judicial discretion in intercourse cases, evidently in recognition of the negative effects of lifetime registration when voluntary intercourse between individuals in an ongoing relationship results in the birth of a child. By disregarding this rational basis for differentiated treatment of the two offender groups, and nullifying a significant portion of the mandatory registration scheme as it pertains to oral copulation offenders, the majority intrudes into the Legislature’s domain and indulges its own notions about what constitutes good public policy.
*1210I.
As defendant explains in his briefing, he met his 16-year-old female victim in an Internet chat room. After chatting with the victim a number of times on the Internet and speaking to her by phone, defendant met her and her young friend at a beach. Defendant brought rum and orange juice, which the girls drank. The victim’s friend got drunk and sick. Before taking the girls home, defendant told the victim, “you owe me something.” The victim orally copulated him.
Defendant was convicted of violating Penal Code1 section 288a, subdivision (b)(1) (section 288a(b)(l)), a statute that, as relevant here, criminalizes voluntary oral copulation with a minor who is 16 or 17 years of age. Because of this conviction, he is subject to mandatory lifetime sex offender registration under section 290. (§ 290, subd. (a)(1)(A).)
This court has acknowledged repeatedly that section 290 serves “an important and proper remedial purpose” (People v. Castellanos (1999) 21 Cal.4th 785, 796 [88 Cal.Rptr.2d 346, 982 P.2d 211] (lead opn. of George, C. J.)) and furthers “vital public interests” (People v. Ansell (2001) 25 Cal.4th 868, 888-889 [108 Cal.Rptr.2d 145, 24 P.3d 1174]) by compelling registration of “sex offenders who require continued public surveillance.” (Maj. opn., ante, at p. 1208; see also In re Alva (2004) 33 Cal.4th 254, 279, fn. 12 [14 Cal.Rptr.3d 811, 92 P.3d 311].) “Given the general danger of recidivism presented by those convicted of criminal sexual misconduct, and the relatively minor burden registration represents, the Legislature may adopt a rule of general application for this class of offenders, and may guard against the demonstrated long-term risk of reoffense by imposing a permanent obligation on persons convicted of such crimes.” (Alva, at pp. 279-280.) It is settled, moreover, that the means chosen to achieve this regulatory goal are reasonable. (Ibid.)
In challenging the trial court’s imposition of lifetime registration, defendant does not challenge the legitimacy of section 290’s remedial purpose. Neither does he argue that requiring lifetime registration of section 288a(b)(l) offenders is not rationally related to that purpose. Rather, he makes the limited contention he was denied equal protection of the laws because persons who violate section 261.5, a statute that, as relevant here, criminalizes voluntary sexual intercourse with a minor who is 16 or 17 years of age, are not also subject to mandatory lifetime registration under section 290.2
*1211Our state constitutional guarantee of equal protection (Cal. Const., art. I, § 7) is substantially equivalent to that contained in the United States Constitution (U.S. Const., 14th Amend.), and our analysis of state and federal equal protection claims is substantially the same. (See Manduley v. Superior Court (2002) 27 Cal.4th 537, 571-572 [117 Cal.Rptr.2d 168, 41 P.3d 3]; Warden v. State Bar (1999) 21 Cal.4th 628, 648, fn. 12 [88 Cal.Rptr.2d 283, 982 P.2d 154].) The precise question here is whether these constitutional guarantees of equal protection are violated by the Legislature’s decision to require mandatory lifetime sex offender registration for persons who engage in voluntary oral copulation with a minor 16 or 17 years of age in violation of section 288a(b)(l), while at the same time providing for discretionary sex offender registration for those who engage in voluntary intercourse with a same-aged minor in violation of section 261.5, subdivision (c). (Compare § 290, subd. (a)(1)(A) [mandatory] with § 290, subd. (a)(2)(E) [discretionary].) If the two groups of criminal offenders are not “similarly situated” for this purpose (Cooley v. Superior Court (2000) 29 Cal.4th 228, 253 [127 Cal.Rptr.2d 177, 57 P.3d 654]; In re Eric J. (1979) 25 Cal.3d 522, 530 [159 Cal.Rptr. 317, 601 P.2d 549]), or if there is any reasonably conceivable state of facts that could provide a rational basis for the difference in treatment (Kasler v. Lockyer (2000) 23 Cal.4th 472, 481-482 [97 Cal.Rptr.2d 334, 2 P.3d 581]), then the Legislature’s decision comports with constitutional equal protection principles and must be upheld as valid.
A. The “Similarly Situated” Requirement
“ ‘ “Persons convicted of different crimes are not similarly situated for equal protection purposes.” [Citations.] “[I]t is one thing to hold, as did [People v. Olivas (1976) 17 Cal.3d 236 [131 Cal.Rptr. 55, 551 P.2d 375]] that persons convicted of the same crime cannot be treated differently. It is quite another to hold that persons convicted of different crimes must be treated equally.” [Citation.]’ [Citation.]” (People v. Barrera (1993) 14 Cal.App.4th 1555, 1565 [18 Cal.Rptr.2d 395].)
The majority generally acknowledges this precept, but finds it inapplicable because section 288a(b)(l) and section 261.5 “both concern sexual conduct with minors” and the “only difference between the two offenses is the nature of the sexual act.” (Maj. opn, ante, at p. 1200.) Notably, however, the majority is unable to cite to a single state or federal decision finding an equal protection violation concerning the direct consequences of conviction where, as here, the challenge involves classes of persons convicted of committing substantively distinct sexual offenses.
*1212Inexplicably, the majority concludes that persons engaging in oral copulation with minors are similarly situated to persons engaging in intercourse with minors, based on clearly inapposite judicial authorities addressing statutes that, for some persons but not for others, criminalized the same sexual conduct or made the same conduct subject to harsher punishment. In Lawrence v. Texas (2003) 539 U.S. 558 [156 L.Ed.2d 508, 123 S.Ct. 2472], for example, the United States Supreme Court held that a Texas statute making it a crime for two persons of the same sex—but not persons of the opposite sex—to consensually engage in certain intimate sexual conduct violates the due process clause of the federal Constitution. Although, as the majority indicates, Justice O’Connor would have resolved Lawrence under equal protection principles, Lawrence offered no occasion to address whether persons who are convicted for engaging in different criminal sexual conduct (e.g., oral copulation with a minor versus intercourse with a minor) are similarly situated for purposes of punishment or other consequences. In State v. Limon (2005) 280 Kan. 275 [122 P.3d 22], the Kansas Supreme Court found Lawrence controlling in finding a criminal statute violated constitutional equal protection guarantees because the punishment it authorized for unlawful voluntary sexual conduct between members of the opposite sex was far less harsh than the punishment it allowed for the same conduct between members of the same sex. In relying on these authorities to conclude that persons are similarly situated when they voluntarily engage in separate and distinct sex-based offenses, only one of which poses the risk of pregnancy and childbearing, the majority takes a rash jurisprudential leap.3
*1213B. The “Rational Relationship” Test
Even assuming that persons who engage in voluntary oral copulation in violation of section 288a(b)(l) are similarly situated to those who engage in voluntary intercourse in violation of section 261.5, the question remains whether the Legislature lacked a plausible rationale, based on any reasonably conceivable state of facts, for distinguishing between the two groups of offenders for registration purposes.
As the Attorney General suggests, it is reasonably conceivable that adults who violate section 261.5 are less likely to repeat their offense than adults who violate section 288a(b)(l). (See maj. opn., ante, at pp. 1203-1204.) Why is that reasonably conceivable? Because many minors, like many adults, can and do distinguish between “going all the way” and other sexual acts, especially when the conduct is voluntary. Viewing section 261.5 as a sex crime involving fewer potential minor victims (and adult offenders) than section 288a(b)(l), the Legislature could plausibly conceive that mandatory lifetime registration is not as critical in section 261.5 cases because the adults who commit this crime have less opportunity to do so.
Apart from this plausible rationale, the Legislature, in fact, had specific public policy reasons for subjecting section 261.5 offenders to discretionary, as opposed to mandatory, registration. In considering a 1997 bill that among other things would have amended section 290 to add section 261.5 to the list of offenses subject to mandatory lifetime registration,4 the Legislature expressly questioned whether extending the requirement to section 261.5 offenders might have negative repercussions when voluntary intercourse between individuals in a relationship results in the birth of a child.5 (Assem. Com. on Public Safety, Analysis of Assem. Bill No. 1303 (1997-1998 Reg. Sess.) as amended Apr. 16, 1997, p. 4 [“How many teen[] mothers would want the father of their child to plead guilty of statutory rape and be subject *1214to a life time registration requirement?”; “Will more cases go to trial instead of settle[] if a registration requirement is mandated?”].) Indeed, it is not difficult to imagine that lifetime sex offender registration of a parent may have the unfortunate effect of stigmatizing a child, especially when the child continues to live with the registering parent. At the same, moreover, the Legislature could plausibly conceive that recidivism was much less of a problem in these situations.
In light of such considerations, a legislative decision to preserve the distinction between intercourse offenders and oral copulation offenders—by continuing to provide for discretionary registration for the former—seems both perfectly sound and particularly appropriate for cases where the minor victim and the section 261.5 offender attempt to establish or maintain a familial relationship around a child resulting from the offense.6 In providing for a dual approach to registration, the Legislature certainly was well aware that the availability of judicial discretion in intercourse cases did not mean all section 261.5 offenders, including predatory offenders lacking any preexisting relationship with their victims, would avoid registration. It simply meant lifetime registration would not be mandatory for all section 261.5 offenders, including those whose poor judgment resulted in a girlfriend’s pregnancy or their own pregnancy.
Seizing on the People’s concession that persons who engage in sexual intercourse often also engage in oral copulation, the majority concludes that, therefore, the “effect of the father’s mandatory registration on the mother and child does not depend on whether the registration is imposed for the act of sexual intercourse or the act of oral copulation.” (Maj. opn., ante, at p. 1205.) While this sort of consideration might properly be raised in a case where a defendant faces mandatory lifetime registration after having committed both oral copulation and intercourse resulting in impregnation, it is, as far as this case and this defendant are concerned, entirely hypothetical and inappropriately asserted. (See People v. Garcia (1999) 21 Cal.4th 1, 11 [87 Cal.Rptr.2d 114, 980 P.2d 829] [defendant lacks standing to assert the equal protection claims of hypothetical felons]; People v. Superior Court (Manuel G.) (2002) 104 Cal.App.4th 915, 934 [128 Cal.Rptr.2d 794] [defendant must show that *1215his rights are affected injuriously by the law he attacks and that he is actually aggrieved by its operation].)
In a related vein, it was suggested at oral argument on this matter that the Legislature could have addressed the special public policy concerns regarding pregnancy and familial issues by expressly limiting the availability of discretionary registration to only those section 261.5 cases involving impregnated victims. While that may have been one way to handle the matter, “ ‘[t]he equal protection clause is not an authorization for the courts to second-guess the Legislature on the best way to deal with aspects of a problem. It protects classes of people from arbitrary discrimination.’ ” (Jasperson v. Jessica’s Nail Clinic (1989) 216 Cal.App.3d 1099, 1110 [265 Cal.Rptr. 301].)
In applying the rational basis test to reject an analogous argument regarding a legislative classification, the United States Supreme Court explained: “Even if the classification involved here is to some extent both underinclusive and overinclusive, and hence the line drawn by Congress imperfect, it is nevertheless the rule that in a case like this ‘perfection is by no means required.’ [Citations.] The provision ‘does not offend the Constitution simply because the classification “is not made with mathematical nicety ....”’ [Citations.] ...[][]... Whether we, or the District Court, think Congress was unwise in not choosing a means more precisely related to its primary purpose is irrelevant.” (Vance v. Bradley (1979) 440 U.S. 93, 108-109 [59 L.Ed.2d 171, 99 S.Ct. 939], fn. omitted.) As one California court aptly observed in quoting the high court on this very point, the fact that a classification “sweeps more broadly than necessary to achieve the legislative purpose, or that other offenses could have been included [in the classification] that would have furthered the legislative purpose, does not undermine [the] conclusion that the classification adopted by the Legislature bears a fair relationship to a legitimate public purpose.” (People v. Conley (2004) 116 Cal.App.4th 566, 576 [10 Cal.Rptr.3d 477].)
By limiting himself to an equal protection challenge, defendant essentially concedes there is an otherwise proper rational basis for requiring mandatory lifetime sex offender registration of section 288a (b)(1) offenders such as himself. Consequently, the issue before us is not—as the majority erroneously suggests—the public policy debate over whether “judicial discretion is a sufficient safeguard to protect against repeat offenders who engage in sexual intercourse but not with offenders who engage in oral copulation.” (Maj. opn., ante, at p. 1204.) Rather, the issue is whether the two offender groups are similarly situated, and if so, whether there is any reasonably conceivable state of facts that could provide a rational basis for the Legislature’s dual approach to registration. (Kasler v. Lockyer, supra, 23 Cal.4th at pp. 481-482.)
*1216As indicated, even assuming, generously, that the two offender groups are similarly situated, the bottom line is that the Legislature had plausible rationales—based on reasonably conceivable facts related to (1) conceivably lower incident and recidivism rates for voluntary intercourse crimes and (2) the potential for pregnancy and childbearing in voluntary intercourse cases—for authorizing discretionary imposition of sex offender registration for section 261.5 offenders while mandating lifetime registration for section 288a(b)(l) offenders. Under these circumstances, no violation of equal protection principles appears.
II.
If it were up to me, I might agree that discretionary registration would be just as appropriate in certain voluntary oral copulation cases as it is in voluntary intercourse cases. But judicial authority to second-guess the legislative determinations of the Legislature is “extremely limited,” and it is well settled that “ ‘the legislative branch is entitled to deference from the courts because of the constitutional separation of powers.’ ” (Connecticut Indemnity Co. v. Superior Court (2000) 23 Cal.4th 807, 814 [98 Cal.Rptr.2d 221, 3 P.3d 868]; see Cal. Const., art. Ill, § 3.) In choosing to nullify the Legislature’s policy judgment requiring lifetime sex offender registration for section 288a(b)(l) offenders, the majority shows a startling disregard for the legislative prerogative to distinguish between classes of offenders whose crimes involve substantially different conduct and pose differing real-life consequences.
Although this court should not shirk its duty to declare a statute invalid when its “ ‘unconstitutionality clearly, positively and unmistakably appears’ ” (In re Dennis M. (1969) 70 Cal.2d 444, 453 [75 Cal.Rptr. 1, 450 P.2d 296]), the separation of powers doctrine bars us from positioning ourselves as a superlegislature willing to second-guess the plausible reasons supporting nonuniform statutory consequences for persons convicted of separate crimes that raise separate public policy concerns. Given the important and vital public purpose of section 290’s mandatory lifetime sex offender registration provisions, and the rational basis underlying its alternative provision for discretionary registration for violators of section 261.5, I see no legitimate basis for the majority’s disturbance of the legislative scheme.
The majority opinion is sure to prompt a spate of equal protection challenges by defendants arguing their crimes cannot be subject to punishment or any other consequence perceived as more severe than that authorized for other distinct but seemingly comparable crimes. At the very least, we may expect challenges regarding the differing sentences and registration consequences authorized for other section 288a offenders and other section 261.5 offenders. (See maj. opn., ante, at pp. 1195-1196.) Today’s decision offers little choice but to overrule legislative values in such cases.
*1217III.
Defendant admits he came upon the minor victim in an Internet chat room, that they then met at a beach away from her parents, and that there he engaged her in oral copulation after furnishing her with alcohol.
In proper deference to the legislative determination that significant public safety concerns for minors justify mandatory lifetime registration for this type of high-risk sex offender, I would reverse the judgment of the Court of Appeal, and remand the matter to that court with directions to affirm the trial court judgment.
Unless otherwise stated, all further statutory citations are to the Penal Code.
In making this contention, defendant argues that, had he engaged in sexual intercourse with the minor victim instead of oral copulation, he would not have been required to register. This argument rests on speculation and conjecture that the victim would have voluntarily engaged in *1211intercourse with him. Indeed, had defendant actually attempted to press the victim for intercourse, she might very well have refused. Of course, any intercourse occurring after such a refusal would have been forcible and subject to mandatory lifetime sex offender registration. (§ 290, subd. (a)(1)(A).)
The majority’s other authorities are similarly inapposite. (See maj. opn., ante, at p. 1199.) Unlike the situation in Newland v. Board of Governors (1977) 19 Cal.3d 705 [139 Cal.Rptr. 620, 566 P.2d 254], this case does not concern a civil law or rule that inexplicably and categorically favors persons convicted of felony sex crimes over persons convicted of misdemeanor sex crimes. (See also Rinaldi v. Yeager (1966) 384 U.S. 305 [16 L.Ed.2d 577, 86 S.Ct. 1497] [state law that required an unsuccessful appellant to repay the cost of a transcript used in preparation of the unsuccessful appeal which applied only to incarcerated appellants but not to those given a suspended sentence, placed on probation, or sentenced only to pay a fine, violated equal protection]; Cooley v. Superior Court, supra, 29 Cal.4th 228 [although the Lanterman-PetrisShort Act and the Sexually Violent Predators Act are both civil commitment statutes, habeas corpus proceedings under the former and probable cause hearings under the latter are not functional equivalents, so persons utilizing these procedural protections are not similarly situated]; In re Eric J., supra, 25 Cal.3d 522 [adults convicted in the criminal courts and youths adjudged wards of the juvenile courts not similarly situated with respect to their interest in liberty]; People v. Nguyen (1997) 54 Cal.App.4th 705, 713,717 [63 Cal.Rptr.2d 173] [rejecting an equal protection challenge to statutes providing that a petty thief who had two prior serious felony convictions, including or in addition to a prior theft-related conviction resulting in confinement, is subject to punishment under the three strikes law (potentially resulting in a term of 25 years to life), while at the same time providing that a petty thief who had two prior serious felony convictions but no prior theft-related conviction is subject only to misdemeanor punishment].)
The legislative history discloses the author of the 1997 bill had sought to add section 261.5 to the list of offenses subject to mandatory lifetime registration in light of the Jacob Wetterling Crimes Against Children and Sexually Violent Offender Registration Act of 1994 (the Jacob Wetterling Act) (42 U.S.C. § 14071), which conditions a state’s receipt of federal funding for drug control on compliance with the act. In considering the bill, the Legislature debated whether mandatory lifetime registration for section 261.5 offenders was necessary to maintain anti-drug funding under that act. (Assem. Com. on Public Safety, Analysis of Assem. Bill No. 1303 (1997-1998 Reg. Sess.) as amended Apr. 16, 1997, pp. 2-3.)
Neither the majority nor the parties address whether judicial elimination of mandatory registration for section 288a (b)(1) offenders causes California to be out of compliance with the Jacob Wetterling Act.
This legislative history undermines defendant’s bald statement that the only logical explanation for the Legislature’s disparate treatment of section 288a (b)(1) offenders and section 261.5 offenders is “antipathy against sexual acts historically associated with homosexuals, as opposed to the heterosexual norm of penile-vaginal intercourse.”
This is not an insignificant percentage of the total number of intercourse cases. Statistics defendant cites indicate that in 30 percent of the cases where teen mothers become pregnant by males over the age of 21, there is a relationship between the parents at the time the child is bom that would be fiscally and socially beneficial for the state to encourage. (See Napa County, District Attorney Web Page, Statutory Rape <http://www.co.napa.ca.us/GOV/ Departments/DeptPage.asp?DID=22400&LID=280> [as of Mar. 6, 2006] [“In 70% of the cases of teen mothers becoming pregnant by males over 21, the relationships end before the birth. The teens have to seek financial aid from the state. These teen families cost the state between $5 to $7 billion each year. It costs more than $10,000 for each teen pregnancy, childbirth, and medical care throughout the first year.”].)