                     FOR PUBLICATION

   UNITED STATES COURT OF APPEALS
        FOR THE NINTH CIRCUIT


 UNITED STATES OF AMERICA,                         No. 19-50014
                Plaintiff-Appellant,
                                                     D.C. No.
                      v.                          2:18-cr-00379-
                                                     ODW-1
 FRANCISCA RODRIGUEZ-GAMBOA,
              Defendant-Appellee.                    OPINION

        Appeal from the United States District Court
           for the Central District of California
        Otis D. Wright II, District Judge, Presiding

              Argued and Submitted July 8, 2020
                    Pasadena, California

                     Filed August 27, 2020

 Before: Kim McLane Wardlaw and Andrew D. Hurwitz,
 Circuit Judges, and Joseph F. Bataillon, * District Judge.

                   Opinion by Judge Hurwitz




     *
       The Honorable Joseph F. Bataillon, United States District Judge
for the District of Nebraska, sitting by designation.
2          UNITED STATES V. RODRIGUEZ-GAMBOA

                          SUMMARY **


                          Criminal Law

    The panel reversed the district court’s dismissal of an
information charging illegal reentry in violation of 8 U.S.C.
§ 1326, and remanded for further proceedings, in a case in
which the defendant was previously removed because of an
“aggravated felony” conviction—possession for sale of
methamphetamine in violation of California Health & Safety
Code § 11378.

    The defendant sought dismissal of the information on the
ground that Section 11378 is categorically overbroad
because the definition of methamphetamine under California
law includes optical and geometric isomers, while the
federal comparator statute covers only the optical isomer.
On limited remand, the district court held an evidentiary
hearing at which it heard unrebutted expert testimony, and
concluded that there is no such thing as a geometric isomer
of methamphetamine.

    The panel held that the district court’s factual finding
that geometric isomers of methamphetamine do not exist,
which it reviewed for clear error, finds overwhelming
support in the record; and rejected the argument that the
California statute’s facial inclusion of “geometrical” isomers
of methamphetamine reflects a legislative determination that
such isomers actually exist.



    **
       This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
          UNITED STATES V. RODRIGUEZ-GAMBOA                   3

    The panel addressed the legal issue whether the factual
impossibility of a state statute being applied more broadly
than a federal comparator means there is a categorical match
between the two, even if the state statute is textually
overbroad. Finding Gonzales v. Duenas-Alvarez, 549 U.S.
183 (2007), most instructive, the panel wrote that, based on
the evidentiary record, there is simply no “realistic
probability”—nor even a theoretical one—of the defendant
facing liability under California law for the possession of
geometric isomers of methamphetamine.                The panel
explained that the purpose of the categorical approach is to
ascertain whether the defendant was necessarily convicted in
state court of conduct that would also violate the relevant
federal law, and wrote that if there is no realistic probability
that this is not the case, the goal of the inquiry is surely
satisfied. The panel concluded that because geometric
isomers of methamphetamine are impossible, there is no
realistic probability that the defendant’s California
methamphetamine statute of conviction will be used to
prosecute someone in connection with geometric isomers of
methamphetamine.


                         COUNSEL

L. Ashley Aull (argued), Chief, Criminal Appeals Section;
Brandon D. Fox, Chief, Criminal Division; Nicola T. Hanna,
United States Attorney; United States Attorney’s Office, Los
Angeles, California; for Plaintiff-Appellant.

David Menninger (argued), Deputy Federal Public
Defender; Office of the Federal Public Defender, Los
Angeles, California; for Defendant-Appellee.
4          UNITED STATES V. RODRIGUEZ-GAMBOA

                             OPINION

HURWITZ, Circuit Judge:

    This appeal requires us to delve once again into the
mysteries of the “categorical approach” to determine
whether a conviction under state law qualifies as a generic
federal offense. See Taylor v. United States, 495 U.S. 575,
602 (1990). The two statutes at issue today both prohibit the
possession of methamphetamine for sale. California law
prohibits the possession for sale of both the geometric and
optical isomers of methamphetamine. Cal. Health & Safety
Code §§ 11033, 11055(d)(2), 11378. 1 The relevant federal
law,     however,     outlaws,      possession       only    of
methamphetamine’s optical isomers. 21 U.S.C. §§ 802(14),
812(c), Schedule II(c), Schedule III(a)(3). Because the state
law’s “greater breadth is evident from its text,” our
traditional jurisprudence would suggest that it is not a
categorical match to the federal law. United States v. Grisel,
488 F.3d 844, 850 (9th Cir. 2007) (en banc), abrogated on
other grounds by United States v. Stitt, 139 S. Ct. 399 (2018).

    But we face an unusual situation today. At our request,
the district court conducted an evidentiary hearing and, after
hearing unrebutted expert testimony, concluded that there is
no such thing as a geometric isomer of methamphetamine.
The Supreme Court has pointedly instructed that the
categorical approach should not be applied in a legal vacuum
and that a finding of overbreadth “requires a realistic
probability, not a theoretical possibility, that the State would
apply its statute to conduct that falls outside the generic

    1
      The California statute refers to “geometrical” isomers. Cal. Health
& Safety Code § 11033. As do the parties and the district court, we use
the terms “geometric” and “geometrical” interchangeably.
          UNITED STATES V. RODRIGUEZ-GAMBOA                   5

definition of a crime.” Gonzales v. Duenas-Alvarez,
549 U.S. 183, 193 (2007). Because there is no such
possibility here, we opt for scientific reality over abstract
legal doctrine and reverse the district court’s dismissal of the
information charging Rodriguez with illegal reentry under
8 U.S.C. § 1326.

                               I.

    We described the facts and procedural history of this
case in a prior opinion, United States v. Rodriguez-Gamboa,
946 F.3d 548 (9th Cir. 2019), and therefore recount them
more briefly here. In 2017, Francisca Rodriguez-Gamboa, a
native and citizen of Mexico, was removed because of an
“aggravated felony” conviction—possession for sale of
methamphetamine in violation of California Health & Safety
Code § 11378.

    Rodriguez later reentered the United States without
inspection. In 2018, she was charged in a criminal complaint
with illegal reentry in violation of 8 U.S.C. § 1326.
Although she initially waived indictment and pleaded guilty,
Rodriguez moved to withdraw her plea and dismiss the
information after we issued our opinion in Lorenzo v.
Sessions, holding that possession of methamphetamine for
sale under California Health & Safety Code § 11378 “does
not qualify as a controlled substance offense under 8 U.S.C.
§ 1227(a)(2)(B)(i).” 902 F.3d 930, 933 (9th Cir. 2018).
Lorenzo found the California statute categorically overbroad
because the definition of certain controlled substances,
including methamphetamine, under California law includes
both optical and geometric isomers, Cal. Health & Safety
Code §§ 11033, 11055(d)(2), while the comparator federal
statute, the Controlled Substances Act (“CSA”), 21 U.S.C.
§§ 802(14), 812(c), Schedule II(c), Schedule III(a)(3),
covers only the optical isomer. 902 F.3d at 935–36.
6         UNITED STATES V. RODRIGUEZ-GAMBOA

    In opposition to Rodriguez’s motion, the government
argued that the California statute’s apparent overbreadth was
illusory because geometric isomers of methamphetamine do
not exist.      The government submitted two expert
declarations in support of that position. The district court
noted that geometric isomers of methamphetamine may not
exist but held that it was bound by Lorenzo. The court
therefore allowed Rodriguez to withdraw her plea and
entered an order dismissing the information.

    After the district court entered its order, the opinion in
Lorenzo was withdrawn, Lorenzo v. Whitaker, 913 F.3d 930
(9th Cir. 2019) (order), and replaced with a non-precedential
memorandum disposition, Lorenzo v. Whitaker, 752 F.
App’x 482 (9th Cir. 2019). The memorandum disposition
reached the same result as the opinion, but pretermitted the
government’s argument that “the facial overbreadth in
California law is of no significance because geometric
isomers of methamphetamine do not in fact exist” because it
was raised for the first time in a petition for panel rehearing.
Id. at 485. The panel, however “d[id] not foreclose the
government from presenting its new argument or new
evidence in another case.” Id.

    In our prior opinion in this case, we held that the district
court did not abuse its discretion in permitting Rodriguez to
withdraw her guilty plea. Rodriguez-Gamboa, 946 F.3d
at 551.     However, we vacated the dismissal of the
information, noting that the opinion on which the district
court had relied had been replaced by a memorandum
disposition that left the government free to raise an argument
in a future case that geometric isomers of methamphetamine
do not exist. Id. at 552. We remanded to the district court
for the limited purpose of addressing that issue. Id. at 552–
53.
          UNITED STATES V. RODRIGUEZ-GAMBOA                   7

    On remand, the district court held an evidentiary hearing
at which the government presented testimony and
declarations from three experts in organic chemistry:
Dr. Travis Williams, professor of chemistry at the
University of Southern California, Dr. Brian Stoltz,
professor of chemistry at the California Institute of
Technology, and Dr. Daniel Willenbring, a drug science
specialist with the Drug Enforcement Administration. All
stated that there are no geometric isomers of
methamphetamine. Rodriguez presented no rebuttal experts.
Accepting the experts’ testimony, the district court
concluded that, because methamphetamine “lacks [certain]
structural     features,”      “geometric    isomers”      of
methamphetamine “are impossible.” We then reassumed
jurisdiction over this appeal.

                              II.

    The district court’s factual finding that geometric
isomers of methamphetamine do not exist, which we review
for clear error, see United States v. Hinkson, 585 F.3d 1247,
1259–60 (9th Cir. 2009) (en banc), finds overwhelming
support in the record. It is grounded in unrebutted expert
testimony that because of the chemical structure of the
methamphetamine molecule, methamphetamine cannot
“possibly have geometric isomers.”

    Rodriguez’s attempt to poke holes in the district court’s
factual finding fails. She argues that the district court should
have interpreted the term “geometrical” isomer in California
Health & Safety Code § 11033 as synonymous with a
diastereomeric isomer, pointing to the parenthetical that
follows the term “geometrical” in the California statute—
“geometrical (diastereomeric) isomers.” Rodriguez then
cites the testimony of one expert that deuterium-labelled
methamphetamine can have diastereomers.                But, the
8          UNITED STATES V. RODRIGUEZ-GAMBOA

unrebutted expert testimony was that although geometric
isomers are a subtype of diastereomers, not all diastereomers
are geometric. And, consistent with that testimony, the
district court held that deuterium-labeled methamphetamine
does not contain geometric isomers. 2

    We also reject the argument that the California statute’s
facial    inclusion     of    “geometrical”      isomers    of
methamphetamine reflects a legislative determination that
such isomers actually exist. Section 11378 prohibits
possession for sale of a number of controlled substances and
their “isomers.” Cal. Health & Safety Code §§ 11055(d)(2)–
(4), (e), 11378. The term “isomer” is in turn defined in
California Health & Safety Code § 11033 as “includ[ing]
optical and geometrical (diastereomeric) isomers.” That
catch-all definition applies to all controlled substances with
isomers, “except as otherwise defined,” id., and is thus
plainly designed not as a legislative finding that
methamphetamine has a geometrical isomer, but rather to
ensure that all isomers of the banned substances are covered.

                                 III.

    Having resolved all other issues relevant to this appeal in
our prior opinion, Rodriguez-Gamboa, 946 F.3d at 551–53,
we now must confront the legal import of the district court’s
factual finding. The ultimate legal issue is whether the
factual impossibility of a state statute being applied more

    2
      For the same reasons, we also reject Rodriguez’s argument that the
term “geometrical” in California Health & Safety Code § 11033 is
defined by the parenthetical “(diastereomeric).” Because all geometrical
isomers are diastereomeric, the parenthetical term is simply descriptive
and does not suggest that all diastereomeric isomers are geometric. See
Tyler v. Cain, 533 U.S. 656, 662 (2001) (“We do not . . . construe the
meaning of statutory terms in a vacuum.”).
          UNITED STATES V. RODRIGUEZ-GAMBOA                   9

broadly than a federal comparator means there is a
categorical match between the two, even if the state statute
is textually overbroad.

    “Under the categorical approach, we compare the
elements of the crime to the generic” federal offense.
Hernandez-Gonzalez v. Holder, 778 F.3d 793, 801 (9th Cir.
2015) (cleaned up). A conviction under a state statute is a
categorical match only “if the state statute—regardless of its
‘exact definition or label’—‘substantially corresponds’ to or
is narrower than” the generic federal offense. Quarles v.
United States, 139 S. Ct. 1872, 1877 (2019) (quoting Taylor,
495 U.S. at 599, 602). If the state statute regulates more
conduct than the federal offense, it is overbroad, and a
defendant convicted under the state statute is not removable
for having committed an aggravated felony. See Rendon v.
Holder, 764 F.3d 1077, 1083 (9th Cir. 2014).

    As we recognized in our prior opinion, Rodriguez-
Gamboa, 946 F.3d at 551–52, California law prohibits the
possession for sale of methamphetamine or its “optical and
geometrical” isomers, Cal. Health & Safety Code §§ 11033,
11055(d)(2), 11378, while the CSA mentions only
methamphetamine’s “optical isomer[s],” 21 U.S.C.
§§ 802(14), 812(c) Schedule II(c), Schedule III(a)(3). Thus,
the California statute textually appears to criminalize more
conduct than the federal one.

    Rodriguez argues that this ends the analysis. Her
argument finds some support in the language of our prior
opinions, such as Grisel, in which we held that Oregon
second-degree burglary was not a burglary offense under the
Armed Career Criminal Act because “[t]he text of the statute
expressly includes in its definition that which the Supreme
Court expressly excluded from the generic, federal
definition,” such as burglary of a booth, vehicle, and aircraft.
10        UNITED STATES V. RODRIGUEZ-GAMBOA

488 F.3d at 850. We stated that if “a state statute explicitly
defines a crime more broadly than the generic definition, no
‘legal imagination’ is required to hold that a realistic
probability exists that the state will apply its statute to
conduct that falls outside the generic definition of the crime”
and a statute’s overbreadth “is evident from its text.” Id.
(quoting Duenas-Alvarez, 549 U.S. at 193).

    But, the overbroad portion of the state statute at issue in
Grisel did not criminalize conduct that could not possibly
occur. Burglary of a booth, vehicle, or aircraft is possible,
albeit perhaps unlikely. Our cases applying Grisel similarly
have involved state laws forbidding conduct that was
factually possible, even if unlikely to be the subject of a
charge. See, e.g., Barrera-Lima v. Sessions, 901 F.3d 1108,
1120 & n.11 (9th Cir. 2018) (finding Washington’s indecent
exposure statute overbroad because it included acts such as
“flashing a passerby for shock value” and “mooning
someone out a window” (cleaned up)); United States v.
Brown, 879 F.3d 1043, 1048 & n.2, 1049–50 (9th Cir. 2018)
(finding Washington state drug conspiracy statute overbroad
because it included a conspiracy where the “only alleged
coconspirator is a federal agent or informant”); United States
v. Jennings, 515 F.3d 980, 989 n.9 (9th Cir. 2008) (finding
Washington statute overbroad because it “explicitly
encompasses conduct that does not present a potential risk
of harm to others”).

    Grisel thus simply stands for the proposition that “[a]s
long as the application of the statute’s express text in the
nongeneric manner is not a logical impossibility, the relative
likelihood of application to nongeneric conduct is
immaterial.” Lopez-Aguilar v. Barr, 948 F.3d 1143, 1147
(9th Cir. 2020) (citing United States v. Valdivia-Flores,
876 F.3d 1201, 1208 (9th Cir. 2017)); see Robles-Urrea v.
          UNITED STATES V. RODRIGUEZ-GAMBOA                  11

Holder, 678 F.3d 702, 707 (9th Cir. 2012) (“In order to hold
that the statute of conviction is overbroad, we must
determine that there is a realistic probability of its
application to conduct that falls beyond the scope of the
generic federal offense.” (cleaned up)). It does not aid us in
applying the categorical approach when there is no
possibility of application of the state statute to nongeneric
conduct.

    In addressing the scenario today before us, we find
Duenas-Alvarez most instructive. In that case, the Supreme
Court stated that “to find that a state statute creates a crime
outside the generic definition of a listed crime in a federal
statute” requires “a realistic probability, not a theoretical
possibility, that the State would apply its statute to conduct
that falls outside the generic definition of a crime.” Duenas-
Alvarez, 549 U.S. at 193. Here, based on the evidentiary
record before us, there is simply no “realistic probability”—
nor even a theoretical one—of Rodriguez facing criminal
liability under California law for the possession of geometric
isomers of methamphetamine.

    To be sure, as Rodriguez notes, Duenas-Alvarez
involved a state statute that facially was a categorical match
to the federal generic crime, but which the petitioner argued
had been applied in an overbroad manner. See id. at 190–
91, 193. But we read the teaching of Duenas-Alvarez more
broadly. The purpose of the categorical approach is to
ascertain whether the defendant was necessarily convicted in
state court of conduct that would also violate the relevant
federal law. If there is no “realistic probability” that this is
not the case, id. at 193, the goal of the inquiry is surely
satisfied.

   Indeed, the Court has implied as much in Moncrieffe v.
Holder, 569 U.S. 184 (2013). There, the government
12        UNITED STATES V. RODRIGUEZ-GAMBOA

expressed concern that the Court’s eventual holding would
suggest that many state statutes prohibiting possession of
firearms were categorically overbroad, because they did not
except antiques, while the corresponding federal generic
crime did. Id. at 205–06. The Court rejected this textual
argument, reiterating that “Duenas-Alvarez requires that
there be ‘a realistic probability, not a theoretical possibility,
that the State would apply its statute to conduct that falls
outside the generic definition of a crime.’” Id. (quoting
Duenas-Alvarez, 549 U.S. at 193). Indeed, it explained
further that, “to defeat the categorical approach in this
manner, a noncitizen would have to demonstrate the State
actually prosecutes the relevant offense in cases involving
antique firearms.” Id. at 206; see also Dominguez v. Barr,
No. 18-72731, 2020 WL 4187377, at *9 (9th Cir. July 21,
2020) (concluding that the “inclusion” of an additional word
“in Oregon’s definition of manufacture does not criminalize
any conduct beyond the reach of the Controlled Substances
Act’s definition” and therefore “[t]here is not a realistic
probability that Oregon prosecutes conduct . . . that is not
covered by the Controlled Substances Act[]”). Because
geometric isomers of methamphetamine are impossible,
there exists “no realistic probability” that Rodriguez’s
California methamphetamine statute of conviction will be
used to prosecute someone in connection with geometric
isomers of methamphetamine. See Moncrieffe, 569 U.S.
at 206 (citation omitted).

    Rodriguez also argues that because the categorical
approach was designed in part to avoid fact-specific
inquiries about how a given defendant committed a state
crime, the evidentiary hearing we ordered in this case is
            UNITED STATES V. RODRIGUEZ-GAMBOA                           13

irrelevant. 3 But the inquiry we asked the district court to
conduct is quite different than looking into the facts of a
crime. We did not ask the court to determine what type of
isomers of methamphetamine Rodriguez’s conviction
actually involved, but rather whether it was physically
possible for anyone to possess a geometric isomer of
methamphetamine. The practical concerns with fact-
specific evidentiary hearings about the defendant’s state
conviction that underly the categorical approach 4 are not
present when the inquiry is a purely scientific one about the
statute of conviction. 5

    3
       See, e.g., Mathis v. United States, 136 S. Ct. 2243, 2252 (2016)
(stating that under the categorical approach, the Court has “avoided any
inquiry into the underlying facts of the defendant’s particular offense”
(cleaned up)); Sykes v. United States, 564 U.S. 1, 7 (2011) (“[W]hile
there may be little doubt that the circumstances of the flight in Sykes’
own case were violent, the question is whether § 35-44-3-3 of the Indiana
Code, as a categorical matter, is a violent felony.”), overruled on other
grounds by Johnson v. United States, 579 U.S. 591 (2015).
    4
      See Taylor, 495 U.S. at 601 (“Would the Government be permitted
to introduce the trial transcript before the sentencing court, or if no
transcript is available, present the testimony of witnesses? Could the
defense present witnesses of its own and argue that the jury might have
returned a guilty verdict on some theory that did not require a finding
that the defendant committed generic burglary?”); United States v.
Sherbondy, 865 F.2d 996, 1008 (9th Cir. 1988) (“The problems with such
hearings are evident. Witnesses would often be describing events years
past. Such testimony is highly unreliable.”).
    5
      Nor are we concerned that our holding today will result in “never-
ending evidentiary hearings on organic chemistry clogging our District
Courts.” Because we hold, as a matter of law, that California’s definition
of methamphetamine is a categorical match to the definition under the
federal CSA, district courts confronting the issue in the future need not
repeat what occurred in this case. See Hart v. Massanari, 266 F.3d 1155,
1175 (9th Cir. 2001) (“A district court bound by circuit authority . . . has
14          UNITED STATES V. RODRIGUEZ-GAMBOA

                                   IV.

     Contrary to Rodriguez’s assertions, we do not today
create a split with the Seventh Circuit. In United States v.
De La Torre, that court addressed whether an Indiana statute
outlawing methamphetamine and its “isomers” was broader
than the generic federal definition, which, as we have noted,
only extends to the optical isomer of methamphetamine.
940 F.3d 938, 951 (7th Cir. 2019) (citations omitted). In that
case, the panel declined to consider declarations from
government experts about whether geometric isomers of
methamphetamine exist because they were presented for the
first time on appeal and crafted for other cases. Id. at 952.
Pointedly, the court noted that its “opinion takes no position
on the scientific merits, nor should it be read as limiting the
government’s ability to present such an argument in future
proceedings.” Id. at 952 n.5.

    In United States v. Ruth, the Seventh Circuit recently
addressed whether an Illinois statute outlawing cocaine and
“its optical, positional, and geometric isomers” was broader
than a federal law which only regulated its “optical and
geometric isomers.” No. 20-1034, 2020 WL 4045885, at *4
(7th Cir. July 20, 2020) (citations omitted). Although the
court found the state statute overbroad, it expressly noted
that the government had not presented evidence that the
apparent overbreadth consisted entirely of impossible
conduct. Id. at *5. More significantly, the court explicitly
“left the door ajar for future science based arguments” and

no choice but to follow it, even if convinced that such authority was
wrongly decided.”). Of course, even for a state statute that is otherwise
a categorical match, an offender may always show overbreadth by
“point[ing] to his own case or other cases in which the state courts in fact
did apply the statute in the special (nongeneric) manner for which he
argues.” Duenas-Alvarez, 549 U.S. at 193.
          UNITED STATES V. RODRIGUEZ-GAMBOA                   15

said that “[t]here may be an occasion where a state statute
covers unquestionably nonexistent conduct, but we do not
need to predetermine how that analysis will look.” Id.

    In this case, the district court held an evidentiary hearing,
heard the testimony of expert witnesses, and concluded that
geometric isomers of methamphetamine do not chemically
exist. Because we know as a scientific fact that dragons have
never existed, we would not find overbroad a state statute
criminalizing the possession of dangerous animals, defined
to include dragons, if the relevant federal comparator
outlawed possession of the same animals but did not include
dragons. We see no reason to reach a different result here.

                               V.

    We reverse the dismissal of the information and remand
for further proceedings.

    REVERSED AND REMANDED.
