                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


UNITED STATES OF AMERICA ,               No. 11-50353
                Plaintiff-Appellee,
                                            D.C. No.
                 v.                      2:92-cr-00256-
                                             DDP-1
RODOLFO TRUJILLO , AKA El Negro,
AKA Alexander Quintana Ruiz,
             Defendant-Appellant.          OPINION


      Appeal from the United States District Court
         for the Central District of California
      Dean D. Pregerson, District Judge, Presiding

                Argued and Submitted
        January 8, 2013—Pasadena, California

                  Filed April 16, 2013

   Before: William C. Canby, Jr., Stephen Reinhardt,
      and Kim McLane Wardlaw, Circuit Judges.

               Opinion by Judge Canby
2                 UNITED STATES V . TRUJILLO

                           SUMMARY*


                           Criminal Law

    The panel vacated the district court’s order denying a
second motion pursuant to 18 U.S.C. § 3582(c)(2) for
reduction of a sentence imposed following the defendant’s
1993 conviction of conspiracy to possess and possessing with
intent to distribute cocaine.

    The panel held that 18 U.S.C. § 3582 contains no
jurisdictional bar to the district court’s entertaining a second
motion under § 3582(c)(2), and that any non-jurisdictional
challenges to the second motion were waived by the
government when it failed to object.

    The panel held that the district court erred in failing to
explain at all its rejection of the defendant’s arguments based
on the factors set forth in 18 U.S.C. § 3553(a).

    The panel held that an upward departure permitted in an
application note to amended U.S.S.G. § 2D1.1 did not violate
the Ex Post Facto Clause.


                            COUNSEL

Wendy T. Wu (argued), Assistant United States Attorney,
Cyber & Intellectual Property Crimes Section; Robert E.


  *
    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 . TRUJILLO                           3

Dugdale, Assistant United States Attorney, Chief, Criminal
Division, Los Angeles, California, for Plaintiff-Appellee.

Brianna J. Mircheff (argued), Deputy Federal Public
Defender, Los Angeles, California, for Defendant-Appellant.


                              OPINION

CANBY, Senior Circuit Judge:

    Rodolfo Trujillo was convicted in 1993 of conspiracy to
possess and of possessing with intent to distribute 2,915
kilograms of cocaine. He was sentenced to 360 months
imprisonment. Subsequently, the Sentencing Commission
amended the Sentencing Guidelines to lower the offense level
applicable to Trujillo, with an application note indicating that
upward departures from the new level might be warranted in
cases involving an excessive quantity of drugs. U.S.S.G.
§ 2D1.1 & Application Note 17.1 The amendment was made
retroactive.2




 1
   Amendment 505, effective Nov. 1, 1994, lowered to 38 the maximum
offense level for trafficking in a quantity greater than 150 kilograms.
U.S.S.G. § 2D1.1(a)(2), (c)(1). Its Application Note 19, which stated that
an upward departure might be warranted on the basis of drug quantity, has
been renumbered multiple times and now appears in the 2012 Guideline
Manual as Application Note 26(B) to Guideline 2D1.1. In this opinion we
refer to it by the number used in the two district court decisions denying
Trujillo’s § 3582(c)(2) motions: Application Note 17.

   2
     Amendment 536, effective Nov. 1, 1995, made Amendment 505
retroactive. U.S.S.G. § 1B1.10(a), (c).
4               UNITED STATES V . TRUJILLO

    Trujillo subsequently moved under 18 U.S.C.
§ 3582(c)(2) for a reduction of his sentence. The district
court denied the reduction, invoking the application note that
permitted an upward departure because of the excessive
quantity of drugs involved. Thirteen years later, Trujillo filed
a second § 3582(c)(2) motion for a reduction of his sentence,
arguing in part that favorable treatment was justified by
various factors under 18 U.S.C. § 3553(a), including his
family ties, his lack of other criminal history, his post-
sentencing rehabilitation, and the need to avoid unwarranted
sentencing disparities. The district court entertained the
successive motion without objection from the government,
but denied relief principally on the ground that Trujillo’s role
in the offense and the amount of drugs involved justified an
upward departure. The district court did not discuss the
§ 3553(a) factors urged by Trujillo. Trujillo now appeals.

    We address three principal issues: First, the government
contends that the district court lacked jurisdiction to entertain
a second motion under § 3582(c)(2). We conclude that
§ 3582 contains no such jurisdictional bar. Any non-
jurisdictional challenges to a second motion were waived by
the government when it failed to object.

    Second, we conclude that the district court erred in failing
to explain at all its rejection of Trujillo’s arguments based on
the § 3553(a) sentencing factors. We accordingly vacate the
district court’s order and remand for further proceedings.

    Third, we reject Trujillo’s contention that the upward
departure under the amended Guideline’s application note
violated the Ex Post Facto Clause.
                UNITED STATES V . TRUJILLO                     5

                               I.

    On appeal, the government contends for the first time that
the district court lacked subject matter jurisdiction to consider
Trujillo’s second § 3582(c)(2) motion. See Ratanasen v.
State of Cal., Dep’t of Health Serv., 11 F.3d 1467, 1473 (9th
Cir. 1993) (jurisdictional questions are an exception to the
general rule that arguments not raised before district court are
waived on appeal). The government begins with the well-
established rule that a district court “may not modify a term
of imprisonment once it has been imposed.” 18 U.S.C.
§ 3582(c). In the absence of an exception to that rule, we
have held that the bar against modifications is jurisdictional.
See United States v. Aguilar-Reyes, 653 F.3d 1053, 1055 (9th
Cir. 2011). Section 3582(c)(2) provides such an exception,
but the government contends that Trujillo’s successive
motion did not meet that section’s requirements, thus leaving
the jurisdictional bar in place. Section 3582(c)(2) states:

        [I]n the case of a defendant who has been
        sentenced to a term of imprisonment based on
        a sentencing range that has subsequently been
        lowered by the Sentencing Commission
        pursuant to 28 U.S.C. 994(o), upon motion of
        the defendant . . . , the court may reduce the
        term of imprisonment, after considering the
        factors set forth in section 3553(a) to the
        extent that they are applicable, if such a
        reduction is consistent with applicable policy
        statements issued by the sentencing
        commission.

18 U.S.C. § 3582(c)(2). The statute in terms clearly does not
prohibit a second motion. The government contends,
6               UNITED STATES V . TRUJILLO

however, that Trujillo’s second motion does not qualify for
§ 3582(c)(2)’s exception because he was serving the sentence
imposed by the district court in response to his first motion
under that section, and the Sentencing Commission did not
lower the Guideline “subsequently” to that sentence.

    The government’s argument relies on a strained reading
of the statute, and a mischaracterization of the first motion
proceeding. The sentence that Trujillo is serving is the one
originally imposed upon him when he was convicted. That
sentence was not modified by the district court in response to
Trujillo’s first motion under § 3582(c)(2); the court simply
declined to “exercise its discretion to lower Trujillo’s
sentence below its current level.” To construe that ruling as
the occasion on which Trujillo was “sentenced to a term of
imprisonment” within the meaning of § 3582(c)(2) is neither
a reasonable interpretation of the statute nor a reasonable
description of what happened at the first motion hearing. See
Dillon v. United States, 130 S. Ct. 2683, 2691 (2010) (“[A]
district court proceeding under § 3582(c)(2) does not impose
a new sentence in the usual sense.”). Trujillo was, and is,
serving a sentence of imprisonment imposed upon him at the
time of his conviction, and the district court had jurisdiction
under § 3582(c)(2) to entertain his second motion because the
term of that sentence was “subsequently” lowered by the
Sentencing Commission.

    Our conclusion that § 3582(c)(2) does not impose or
result in a jurisdictional bar to a second motion is buttressed
by the Supreme Court’s instruction that we construe statutory
limitations as non-jurisdictional in the absence of clear
directions from Congress. “If the Legislature clearly states
that a threshold limitation on a statute’s scope shall count as
jurisdictional, then courts and litigants will be duly instructed
                UNITED STATES V . TRUJILLO                   7

. . . . But when Congress does not rank a statutory limitation
on coverage as jurisdictional, courts should treat the
restriction as nonjurisdictional in character.” Arbaugh v.
Y&H Corp., 546 U.S. 500, 515–16 (2006) (internal citations
and footnote omitted). The label “jurisdictional” is properly
reserved for designating the types of cases and individuals
within a court’s reach. Kontrick v. Ryan, 540 U.S. 443, 455
(2004). It is ordinarily not the correct classification for
“claim-processing rules” such as temporal or, as here,
numerical limitations on motions addressed to the same
tribunal. See id. at 455–56; Joshi v. Ashcroft, 389 F.3d 732,
734–35 (7th Cir. 2004) (holding that a limitation on the
number of motions to reopen or reconsider does not create a
jurisdictional bar); cf. Socop-Gonzalez v. INS, 272 F.3d 1176,
1192–93 (9th Cir. 2001) (en banc) (holding that a 90-day
filing deadline for motions to reopen or reconsider did not
create a jurisdictional bar). “[T]he emergent distinction . . .
is between those [limits] that govern the transition from one
court (or other tribunal) to another, which are jurisdictional,
and other [limits], which are not.” Joshi, 389 F.3d at 734.

    Our sister Circuits have divided on the question whether
a district court lacks jurisdiction to entertain a second
§ 3582(c)(2) motion. The Seventh and Fourth Circuits have
precluded second motions in terms suggesting a lack of
jurisdiction. United States v. Redd, 630 F.3d 649, 651 (7th
Cir. 2011); United States v. Goodwyn, 596 F.3d 233, 236 (4th
Cir. 2010); see also United States v. Randall, 666 F.3d 1238,
1242–43 & n.6 (10th Cir. 2011) (upholding denial of
untimely motion for reconsideration of order denying
§ 3582(c)(2) relief, but under abuse of discretion standard).

    The Third Circuit, however, upheld a district court’s
entertainment of a second § 3582(c)(2) motion in a case
8               UNITED STATES V . TRUJILLO

closely parallel to ours. United States v. Weatherspoon,
696 F.3d 416 (3rd Cir. 2012), cert. denied, 133 S. Ct. 1301
(2013). In Weatherspoon, as here, the government failed to
object to a district court’s entertainment of a second
§ 3582(c)(2) motion and challenged it for the first time on
appeal as a jurisdictional defect. The Third Circuit referred
to the contrary circuit authority, and stated:

       Though our sister circuits may be right that such
       silence [of Congress in failing specifically to
       authorize successive motions], when read in light
       of the statute’s purpose of restricting a district
       court’s authority to revisit a criminal sentence,
       means that a defendant is only entitled to one bite
       at the apple, it does not follow that this restriction
       goes to the subject matter jurisdiction of the
       district court. After all, a rule derived from
       congressional silence does not support an
       inference that Congress has “clearly stated” its
       intent to limit a district court’s jurisdiction to one
       § 3582(c)(2) motion. See . . . Animal Sci. Prods.,
       Inc., 654 F.3d [462,] 468 [3rd Cir. 2011]
       (applying the Arbaugh “clearly states” test).

Id. at 421. We agree with this jurisdictional analysis and
reject any contrary views that may have been adopted in
whole or in part by other circuits.

    Holding as we do that the district court had jurisdiction to
entertain Trujillo’s second motion under § 3582(c)(2), we
need not address the validity or applicability of non-
jurisdictional restrictions of such motions urged by the
government, including law of the case or waiver by Trujillo
in not appealing the denial of his first motion. Those non-
                   UNITED STATES V . TRUJILLO                             9

jurisdictional challenges were waived by the government’s
failure to object in the district court. See Slaven v. Am.
Trading Transp. Co., 146 F.3d 1066, 1069 (9th Cir. 1998).

                                    II.

    We proceed to the merits of Trujillo’s appeal.3 In
Trujillo’s second § 3582(c)(2) motion, he asked for a
sentence reduction based on United States v. Booker,
543 U.S. 220 (2005), Amendments 505 and 536 to the U.S.
Sentencing Guidelines (the basis of his first § 3582(c)(2)
motion), and the § 3553(a) factors. The district court
correctly noted that Booker did not lower the Sentencing
Guidelines, but rather made them advisory; it was also a
decision of the Supreme Court and not, as § 3582(c)(2)
requires, a reduction enacted by the Sentencing Commission.
See Dillon v. United States, 130 S. Ct. 2683, 2693 (2010).
The court then explained that it would not effectively reverse
the previous district court’s denial of Trujillo’s § 3582(c)(2)
motion based on Amendments 505 and 536. The court cited
Application Note 17 to U.S.S.G. § 2D1.1, which allowed for
an upward departure based on drug quantity in extraordinary
cases. The court explained:

         Defendant’s conviction involved more than
         2,800 kilograms of cocaine, an amount well
         above ten times the 150 kilogram minimum in

    3
      W e have jurisdiction under 28 U.S.C. § 1291 to review the
discretionary denial of a § 3582(c)(2) sentence reduction motion. United
States v. Colson, 573 F.3d 915, 916 (9th Cir. 2009). W e review for abuse
of discretion, which occurs if the district court does not apply the correct
law or predicates its decision on a clearly erroneous factual finding.
United States v. Chaney, 581 F.3d 1123, 1125 (9th Cir. 2009). W e review
de novo any underlying questions of law. Id.
10              UNITED STATES V . TRUJILLO

       Amendment 505’s amended drug quantity
       table . . . . In addition, Defendant was one of
       the masterminds behind the . . . distribution of
       the cocain[e] at issue. In light of these facts,
       the court has consider[ed] Defendant’s
       sentence under the new guidelines pursuant to
       Amendment 505 and concludes that here—
       where more than 10 times the maximum drug
       quantity established by offense level 38 was
       in Defendant’s possession—an upward
       departure is warranted. Accordingly, the
       court declines to . . . resentence Defendant.

The order did not discuss any of the § 3553(a) factors that
Trujillo argued in support of a lower sentence. Trujillo’s
presentation about the § 3553(a) factors comprised eight
pages of argument and an additional 39 pages of addenda
consisting of health records and certificates of achievement
from inmate programs. Congress enacted 18 U.S.C.
§ 3553(a) in order to ensure that judges impose sentences
“sufficient, but not greater than necessary, to comply with the
purposes” of imprisonment, such as deterrence, punishment,
and public safety. 18 U.S.C. § 3553(a), (a)(2); see Pepper v.
United States, 131 S. Ct. 1229, 1242 (2011). The factors
include: the nature and circumstances of the offense and the
history and characteristics of the defendant; the purposes of
sentencing; the kinds of sentences available; the sentences
and ranges established by the Sentencing Guidelines; relevant
policy statements issued by the Sentencing Commission; the
need to avoid unwarranted sentencing disparities among
similarly situated defendants; and the need to provide
restitution to victims. 18 U.S.C. § 3553(a). Accordingly, the
Supreme Court has consistently instructed that “the
punishment should fit the offender and not merely the crime,”
                UNITED STATES V . TRUJILLO                  11

and thus judges should use “the fullest information possible
concerning the defendant’s life and characteristics” to
determine the appropriate sentence. Pepper, 131 S. Ct. at
1235, 1240 (quoting Williams v. New York, 337 U.S. 241,
246–47 (1949)); Gall v. United States, 552 U.S. 38, 49–50
(2007) (“[A]fter giving both parties an opportunity to argue
for whatever sentence they deem appropriate, the district
judge should then consider all of the § 3553(a) factors to
determine whether they support the sentence requested by a
party.”); accord United States v. Ringgold, 571 F.3d 948, 950
(9th Cir. 2009).

    A district court is required to “consider” the § 3553(a)
factors both in the initial imposition of a sentence and in any
subsequent reduction of a sentence after the modification of
a guidelines range by the Sentencing Commission. See
18 U.S.C. § 3582(a) (upon imposition of term of
imprisonment, sentencing court “shall consider the factors set
forth in section 3553(a) to the extent that they are
applicable”); 18 U.S.C. § 3582(c)(2) (court “may reduce the
term of imprisonment, after considering the factors set forth
in section 3553(a) to the extent they are applicable”). The
district court’s duty to consider the § 3553(a) factors
necessarily entails a duty to provide a sufficient explanation
of the sentencing decision to permit meaningful appellate
review. United States v. Carty, 520 F.3d 984, 992 (9th Cir.
2008) (en banc). We have held that there is no mechanical
requirement that a sentencing court discuss every factor; even
where a judge never mentions “§ 3553(a),” it may be clear
from the court’s experience and consideration of the record
that the factors were properly taken into account. Id. at
995–96; see Rita v. United States, 551 U.S. 338, 356–57
(2007) (“[W]hen a judge decides simply to apply the
12              UNITED STATES V . TRUJILLO

Guidelines to a particular case, doing so will not necessarily
require lengthy explanation.”).

      The Supreme Court has instructed, however, that
“[w]here the defendant or prosecutor presents nonfrivolous
reasons for imposing a different sentence . . . the judge will
normally go further and explain why he has rejected those
arguments. Sometimes the circumstances will call for a brief
explanation; sometimes they will call for a lengthier
explanation.” Rita, 551 U.S. at 357. Our en banc court, too,
has made clear that “when a party raises a specific,
nonfrivolous argument tethered to a relevant § 3553(a) factor
. . . then the judge should normally explain why he accepts or
rejects the party’s position.” Carty, 520 F.3d at 992–93; see
United States v. Stoterau, 524 F.3d 988, 999 (9th Cir. 2008).
Here, Trujillo presented fairly extensive arguments and
evidence concerning the “characteristics of the defendant,”
pursuant to 18 U.S.C. § 3553(a)(1): in addition to citing his
lack of a prior criminal record, he presented evidence of: his
educational history including graduation from technical
school as a mechanical electrician; the support of his siblings
and two children; his considerable involvement in
constructive prison activities; his post-sentencing
rehabilitation; and his failing health. He also argued that the
judge should consider unwarranted sentencing disparities
pursuant to § 3553(a)(6). Trujillo cited United States v.
Zakharov, 468 F.3d 1171 (9th Cir. 2006), a case in which a
defendant convicted of possession and conspiracy to possess
with intent to distribute 9,200 kilograms of cocaine was
sentenced to 240 months imprisonment with five years
supervised release—notably, after both the enactment of the
Guidelines amendment that lowered the maximum offense
level for drug distribution to 38 and the application note that
permitted judges to depart upward if the amount distributed
                 UNITED STATES V . TRUJILLO                      13

was greater than ten times the maximum amount listed for
that offense level (150 kilograms of cocaine). Id. at 1175.
Trujillo also cited United States v. Perlaza, 439 F.3d 1149,
1155, 1158 (9th Cir. 2006) where nine defendants were all
sentenced to 200 months or below for smuggling about 2000
kilograms of cocaine.4 (Trujillo’s sentence was 360 months
for 2,915 kilograms).

    In Pepper and Gall, the Supreme Court made clear that
postsentencing or post-offense rehabilitation—particularly in
light of its tendency to reveal a defendant’s likelihood of
future criminal conduct—was a critical factor to consider in
the imposition of a sentence. See Pepper, 131 S. Ct. at
1242–43 (citing 18 U.S.C. § 3553(a)(2)(B)–(C)); Gall,
552 U.S. at 59 (same). In Kimbrough v. United States,
552 U.S. 85, 91 (2007), the Court also emphasized that
unwarranted disparities between offenders—and the concern
that such disparities would result in imposing sentences
“greater than necessary” to achieve the objectives of
sentencing—was an important factor for district courts to
consider.

    Regardless of the ultimate force of Trujillo’s arguments,
they are not frivolous. The district court did not address any
of them, even to dismiss them in shorthand. This total
omission goes against the explicit policy considerations in
Rita, where the Supreme Court explained that while a district
judge need not enumerate every factor supporting a particular
sentence, “[A] statement of reasons is important. The
sentencing judge should set forth enough to satisfy the


  4
    The convictions of all but one of the defendants in Perlaza were
reversed on jurisdictional grounds unrelated to the length of their
sentences.
14                 UNITED STATES V . TRUJILLO

appellate court that he has considered the parties’ arguments
and has a reasoned basis for exercising his own legal
decisionmaking authority.” 551 U.S. at 356.

    The government asserts that the district court’s
explanation was adequate because its order began, “Having
reviewed the papers submitted to the court . . . ,” thereby
suggesting that the record had been adequately and
thoroughly considered. We find this argument unpersuasive.
First, the Rita instruction is concerned with explanation, not
merely consideration. Underlying this emphasis is a concern
that appellate courts and the public have an adequate basis for
concluding that sentencing occurred in a reasonable fashion.
551 U.S. at 357. It is true that, in Carty, we relied in part on
the district judge’s statement that he had “reviewed the
papers,” and because the papers had discussed the § 3553(a)
factors, we assumed that the judge had considered them. Id.
at 996. But we made this observation after considerable
discussion of other elements supporting our conclusion that
the sentencing judge, who had held an extensive sentencing
hearing dealing with the § 3553(a) factors, had set forth a
sufficient explanation of the sentence.5 See id. at 990. We do
not interpret Carty to stand for the proposition that a mere
statement that the judge had read the papers is, by itself and
automatically, sufficient as an explanation of the judge’s
treatment of the § 3553(a) factors. To draw such a conclusion
from Carty would deprive of all force the language in Rita
and Carty itself stating that a sentencing judge presented with
nonfrivolous arguments on § 3553(a) factors should


 5
  Carty also placed considerable emphasis on the fact that Carty’s case
was a simple one and that the sentence imposed was within the
Guidelines. Carty, 520 F.3d at 995. The denial of Trujillo’s § 3582(c)(2)
motion resulted in a sentence above the amended Guideline.
                UNITED STATES V . TRUJILLO                   15

ordinarily explain why he rejects them. Rita, 551 U.S. at
357–58; Carty, 520 F.3d at 992–93.

    The government is correct in noting that the district court
discussed the quantity of drugs involved and Trujillo’s role,
both appropriate considerations under § 3553(a)(1). But Rita
and this Court instruct that, “[w]here the defendant or
prosecutor presents nonfrivolous reasons for imposing a
different sentence,” a sentencing judge “will normally go
further and explain why he has rejected those arguments.”
Rita, 551 U.S. at 357; accord Carty, 520 F.3d at 992–93;
Stoterau, 524 F.3d at 999–1000. Trujillo presented
nonfrivolous arguments, and the district court did not at all
explain the reasons for rejecting them; this was legal error.
We vacate the district court’s order and remand to the district
court for proceedings not inconsistent with this opinion.

                              III.

    Finally, Trujillo argues that the district court, in
employing an upward departure pursuant to Application Note
17, violated the Ex Post Facto Clause, U.S. Const. Art. I, § 9,
cl. 3. For a court to violate the Ex Post Facto Clause in its
enforcement of a new law, “the law must be retrospective,
that is, it must apply to events occurring before its enactment;
and second, it must disadvantage the offender affected by it.”
Hamilton v. United States, 67 F.3d 761, 764 (9th Cir. 1995)
(quoting Miller v. Florida, 482 U.S. 423, 430 (1987))
(internal quotation marks omitted).

    The district court did not explicitly address Trujillo’s
argument. In any case, the argument fails. Although the
revision of the sentencing guidelines and the addition of the
application note were clearly retrospective, they did not
16              UNITED STATES V . TRUJILLO

disadvantage Trujillo: the permission for upward departure
merely caused him to retain the same sentence that he had
been given before the law was revised. See U.S.S.G.
§ 2D1.1, Application Note 17.

    This case is not like Hamilton, which involved a
defendant who was originally sentenced as a career offender
under the 1988 Guidelines, in part because his offense of
conviction was determined to be a “crime of violence.” The
Sentencing Commission thereafter amended the applicable
Guideline to specify that Hamilton’s offense of conviction,
possession of a firearm by a felon, did not qualify as a crime
of violence. The amendment was retroactive. When
Hamilton moved to modify his sentence to take account of the
Guideline amendment, the district court gave him the benefit
of the amendment, but then applied the 1993 Guidelines that
resulted in a larger sentence than he would have been subject
to under the original 1988 Guidelines, as amended only by
the retroactive amendment by the Sentencing Commission.
We held that application of the new, disadvantageous 1993
Guidelines violated the Ex Post Facto clause, even though the
new sentence did not exceed the original one. Hamilton,
67 F.3d at 764–65.

    This case differs from Hamilton in two important
particulars. First, Trujillo was not subjected to a new and
more severe sentence under a new set of Guidelines unrelated
to the retroactive amendment applicable to his case. Instead,
Trujillo seeks to take advantage of one portion of a single
amendment to the Guideline under which he was sentenced,
and to disregard a condition that was added to the Application
Note to that very Guideline as part of the same amendment.
We agree with the government that Trujillo is not entitled to
select only the favorable portion of an amendment to a single
                UNITED STATES V . TRUJILLO                   17

Guideline and to disregard the unfavorable portion, so long as
his overall sentence is not increased beyond that originally
imposed.

    Second, the amendment in Trujillo’s case, taken as a
whole and applied to his original sentence, did not render the
term of that sentence necessarily erroneous. The Guidelines
as amended still permitted the sentence Trujillo originally
received. Thus, the assessment of prejudice resulting from
the district court’s denial of relief to Trujillo is based on
whether his sentence after that denial exceeded his original
sentence, which it did not.

    In Hamilton, in contrast, the retroactive amendment
providing that Hamilton’s offense of conviction was not a
crime of violence rendered his sentence erroneous. We
therefore compared his new sentence of 77 months to the
12–18 month sentence he would have been required to
receive had the retroactive amendment been in effect at his
original sentencing. Hamilton, 67 F.3d at 765. He was
accordingly disadvantaged by the application of the new set
of Guidelines, in violation of the Ex Post Facto clause.
Because Trujillo’s original sentence was not rendered legally
erroneous by the Sentencing Commission’s retroactive
amendment, we compare his current sentence to his original
sentence of 360 months to determine whether Application
Note 17 “disadvantaged” him. Because the district court’s
denial of relief under § 3582(c)(2) did not result in a sentence
that was longer than the one originally imposed, there was no
Ex Post Facto Clause violation.
18              UNITED STATES V . TRUJILLO

                             IV.

    To sum up: The district court had jurisdiction to entertain
Trujillo’s second motion to modify his sentence under
§ 3582(c)(2). Its denial of relief did not violate the Ex Post
Facto Clause. Because the district court did not explain in
any way its reasons for rejecting Trujillo’s arguments
regarding the § 3553 factors, however, we vacate the district
court’s order and remand for further proceedings.

     VACATED and REMANDED.
