FOR PUBLICATION
  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                   No. 08-30050
                Plaintiff-Appellee,
               v.                             D.C. No.
                                           CR-06-00091-LRS
ROBERT LEWIS NORWOOD,
                                              OPINION
             Defendant-Appellant.
                                      
    On Remand From The United States Supreme Court

                   Filed February 17, 2010

   Before: Thomas M. Reavley* Richard C. Tallman, and
            Milan D. Smith, Jr., Circuit Judges.

           Opinion by Judge Milan D. Smith, Jr.




  *The Honorable Thomas M. Reavley, Senior United States Circuit
Judge for the Fifth Circuit, sitting by designation.

                             2501
2504              UNITED STATES v. NORWOOD




                         COUNSEL

Robert J. Pfister and Andrew B. Brettler, Simpson Thacher &
Bartlett LLP, Los Angeles, California, for the defendant-
appellant.

James A. McDevitt and K. Jill Bolton, United States Attor-
ney, Spokane, Washington, for the plaintiff-appellee.


                         OPINION

MILAN D. SMITH, JR., Circuit Judge:

   In this appeal, Defendant-Appellant Robert L. Norwood
challenges his jury conviction for possession of cocaine base
with intent to distribute in violation of 21 U.S.C. § 841(a)(1)
and possession of a firearm in furtherance of a drug traffick-
ing crime in violation of 18 U.S.C. § 924(c)(1)(A). Norwood
claims violation of his Sixth Amendment right to confront his
accuser and violation of his due process rights both in trial
and at sentencing. Norwood also claims that the evidence was
insufficient to convict him for possession of a firearm in fur-
therance of a drug trafficking crime.

   We affirmed Norwood’s conviction and sentence in United
States v. Norwood, 

(9th Cir. 2009). The matter
is again before us on remand from the United States Supreme
Court. The Court vacated our earlier opinion and remanded
for reconsideration of Norwood’s Confrontation Clause claim
in light of Melendez-Diaz v. Massachusetts, 

(2009). We again affirm Norwood’s conviction and sentence.
                   UNITED STATES v. NORWOOD                 2505
   FACTUAL AND PROCEDURAL BACKGROUND

   In April of 2006, police responded to a domestic violence
call in Spokane, Washington. Upon entering the home, the
police encountered Norwood in the bedroom lying on his bed.
They smelled marijuana, and asked Norwood to step outside.
In response to police questioning, Norwood admitted he had
“just smoked a joint,” but denied having any other drugs in
the bedroom. The officers then arrested Norwood, and while
searching him discovered 0.86 grams of crack cocaine and
over $2500 dollars in his pockets.

   After obtaining a warrant, the police searched Norwood’s
home and vehicle. In the car, police found $7000 in cash, sep-
arated into $1000 tightly wrapped bundles. In the bedroom,
the police discovered two baggies containing a total of 7.7
grams of cocaine base and a digital scale dusted with drug
residue underneath the dresser next to the bed. Police also
found a wood box containing several “marijuana blunts,” or
butts of marijuana joints. In the closet, police found 42.4
grams of harvested marijuana in an ice cream box. Between
the mattress and the box spring of the bed, police found a 25
caliber semiautomatic handgun. The police did not find any
other drug paraphernalia.

   On August 2, 2007, Norwood was indicted in federal dis-
trict court on three counts: (1) being a felon in possession of
a firearm in violation of 18 U.S.C. §§ 922(g)(1) and 924(e);
(2) possessing cocaine with the intent to distribute in violation
of 21 U.S.C. §§ 841(a)(1), 841(b)(1)(B), and 18 U.S.C. § 2;
and (3) possessing a firearm in furtherance of a drug traffick-
ing crime in violation of 18 U.S.C. § 924(c)(1). The govern-
ment eventually dismissed the first count and proceeded to
trial on the second and third counts. Norwood made a Federal
Rule of Criminal Procedure 29 motion to dismiss at the close
of the government’s case, another at the close of the defen-
dant’s case, and still a third following trial, each of which was
denied.
2506              UNITED STATES v. NORWOOD
   As part of its case-in-chief, the government presented an
affidavit prepared by Jodi Arndt, an employee at the Wash-
ington Department of Employment Security, which certified
that “a diligent search of the department’s files failed to dis-
close any record of wages reported for [Norwood] from Janu-
ary 1, 2004 through March 31, 2007.” Although Arndt did not
appear in person to testify, the court admitted her affidavit as
circumstantial evidence that Norwood had no legal source for
the large amounts of cash that were found on his person and
in his car.

   During closing argument, Norwood’s counsel argued to the
jury that the drugs found in Norwood’s apartment were for
personal use, and suggested that Norwood had been smoking
the crack through the marijuana blunts that were found on the
scene, but which had not been seized or tested. The prosecutor
responded to the defense’s comments as follows: “When we
talk about those blunts, yeah, it would have been real nice if
the police got those. The police didn’t get those, but they
admitted that, but you know what, the defendant didn’t tell
them that he was smoking the marijuana with the crack
cocaine.” The defense immediately objected and moved for a
mistrial on the basis that Norwood’s right to silence had been
violated. The district court sustained the objection and
directed the jury not to consider the prosecution’s comment.
The court denied the motion for a mistrial.

  On October 31, 2007, the jury returned a verdict of guilty
on both counts. The district court sentenced Norwood to 120
months in prison for Count 2 and 60 months for Count 3, to
run consecutively. Norwood appealed to this court.

                STANDARD OF REVIEW

   Norwood alleges that his Sixth Amendment right to con-
front his accusers was violated when the district court admit-
ted into evidence a written affidavit without requiring the
affiant to testify on the stand. We review admission of a
                  UNITED STATES v. NORWOOD                 2507
declarant’s out-of-court statements de novo to test for possible
violations of the Confrontation Clause. Lilly v. Virginia, 

, 137 (1999). If a constitutional violation has
occurred, we then review for harmless error. Chapman v. Cal-
ifornia, 

, 21-22 (1967).

   Norwood also alleges that the prosecution’s reference to the
fact that he had not spoken with police officers regarding pos-
sible use of cocaine in the marijuana blunts violated his due
process rights. We review a claim that the prosecution’s com-
ment has violated the defendant’s right to silence de novo.
United States v. Bushyhead, 

, 911 (9th Cir.
2001). If the prosecution’s comment is determined to be
improper, we then apply harmless error review. 

argues that the evidence was insufficient
to convict him on the count of possession of a firearm in fur-
therance of a drug trafficking crime. When the defendant has
moved for a judgment of acquittal after the close of evidence,
this court reviews denial of the motion de novo. United States
v. Rios, 

, 1011 (9th Cir. 2006). We will not
overrule a conviction if “ ‘after viewing the evidence in the
light most favorable to the prosecution, any rational trier of
fact could have found the essential elements of the crime
beyond a reasonable doubt.’ ” 

v. Vir-
ginia, 

, 319 (1979)).

                        DISCUSSION

A.   Claimed Violation of Norwood’s Sixth Amendment
     Rights

   [1] The Sixth Amendment of the U.S. Constitution guaran-
tees an accused the right “to be confronted with the witnesses
against him.” U.S. CONST. amend. VI. The Supreme Court has
interpreted this right to apply to out-of-court statements as
well as in-court testimony. Crawford v. Washington, 

, 50-51 (2004). As the Court summarized in Crawford,
2508                UNITED STATES v. NORWOOD
“[t]estimonial statements of witnesses absent from trial have
been admitted only where the declarant is unavailable, and
only where the defendant has had a prior opportunity to cross-
examine.” 

   [2] The Supreme Court has yet to define the full extent to
which rights under the Confrontation Clause are applicable to
testimonial and nontestimonial statements. However, in
Melendez-Diaz, the Court provided additional guidance, con-
cluding that “certificates of analysis” verifying the identity of
a contraband chemical substance are testimonial under Craw-

, 2532. Quoting Crawford, the Court
explained that the “certificates of analysis” (which are “quite
plainly affidavits”) are “incontrovertibly a solemn declaration
or affirmation made for the purpose of establishing or proving
some fact” and “functionally identical to live, in-court testi-
mony.” 

marks omitted). Accordingly,
Melendez-Diaz held that such affidavits are inadmissible
unless the affiant testifies at trial, or is unavailable at trial but
had earlier been available for cross-examination. 

case, the government concedes that under Melendez-
Diaz, Washington Department of Employment Security
Assistant Records Officer Jodi Arndt’s affidavit, prepared for
use at Norwood’s trial to prove the absence of any record of
Norwood having legitimate employment, should not have
been admitted without Arndt presenting herself at trial for
examination.

   [3] In light of the government’s concession that admission
of Arndt’s affidavit violated Norwood’s Sixth Amendment
rights, we must remand for a new trial unless the government
demonstrates beyond a reasonable doubt that admission of the
evidence was harmless. 

.

     Whether such an error is harmless in a particular
     case depends upon a host of factors . . . includ[ing]
     the importance of the witness’ testimony in the pros-
                   UNITED STATES v. NORWOOD                 2509
    ecution’s case, whether the testimony was cumula-
    tive, the presence or absence of evidence
    corroborating or contradicting the testimony of the
    witness on material points, the extent of cross-
    examination otherwise permitted, and, of course, the
    overall strength of the prosecution’s case.

Delaware v. Van Arsdall, 

, 684 (1986).

   Under the circumstances of this case, the government has
met its burden. Unlike the affidavit in Melendez-Diaz, the
affidavit in this case was not offered to prove an element of
the offense, nor was it the sole evidence of any relevant fact.
Rather, the testimony provided by the disputed affidavit was
not particularly important to the case, and was cumulative.

   Specifically, the affidavit was offered to prove the lack of
any record that Norwood had legitimate employment that
might explain his possession of $7,000 in cash stored in sepa-
rate rolls of $1,000, bundled in duct tape, in the center console
of his vehicle, and another $2,531 in cash on his person.

   The amount of cash and Norwood’s method of storing it
strongly suggest that the money did not derive from a legiti-
mate source. Further, the jury heard evidence from Nor-
wood’s girlfriend that he rarely left the house during the day,
did not receive paychecks from any regular employment, and
that his only job involved occasional cleaning of rental units.
Thus, Norwood’s girlfriend’s testimony established the same
fact as the disputed affidavit—that Norwood did not have any
sort of job that would have led to employment records with
the state—making the affidavit merely cumulative. Thus,
although the government relied on the affidavit in arguing to
the jury that the cash could not have derived from a legitimate
source, the government could have made precisely the same
argument based on the testimony of Norwood’s girlfriend.
Accordingly, the district court’s admission of the affidavit,
and the government’s reliance on it, were harmless.
2510              UNITED STATES v. NORWOOD
   Other physical evidence suggested that Norwood was in the
drug distribution business. The smell of marijuana greeted the
officers when they arrived at Norwood’s house in response to
the domestic disturbance call. Norwood admitted to smoking
marijuana, and the police found two bags of marijuana in the
house. When the police found him, Norwood was lying on his
bed in his home. A loaded 25-caliber handgun was found
under his mattress. A tray bearing Norwood’s fingerprints
was found under the nightstand next to Norwood’s side of the
bed. On that tray were an electronic scale with traces of
cocaine on it, as well as baggies of crack cocaine. Bundles of
crack cocaine were also found on Norwood’s person when he
was searched incident to his arrest.

   [4] In sum, disregarding the affidavit entirely, the evidence
against Norwood on the elements of the offense of possession
of cocaine base with intent to distribute was sufficient to
establish his guilt beyond any reasonable doubt. Cf. United
States v. Larson, 

, 1108 (9th Cir. 2007) (en
banc) (concluding that a Confrontation Clause error was
harmless beyond any reasonable doubt where other evidence
established defendant’s participation in drug conspiracy).

B.     Claimed Violation of Norwood’s Due Process Rights
       at Trial and Sentencing

   Norwood charges that his due process rights were violated
both at trial and at sentencing. First, he argues that comments
made by the prosecution during closing arguments violated
his Fifth Amendment right to silence. Second, he argues that
the allegedly arbitrary sentencing distinction between crack
and powder cocaine violates the Due Process Clause of the
Fifth Amendment as well as the Eighth Amendment prohibi-
tion against cruel and unusual punishment. We address these
arguments in turn.

  The Fifth Amendment protects a defendant’s right to
remain silent by assuring that “silence will carry no penalty,”
                  UNITED STATES v. NORWOOD                 2511
and that the prosecution cannot use a defendant’s silence to
imply guilt. Doyle v. Ohio, 

, 618 (1976). As
acknowledged by this court, “[t]he privilege against self-
incrimination prevents the government’s use at trial of evi-
dence of a defendant’s silence — not merely the silence itself,
but the circumstances of that silence as well.” 

.

   [5] However, where “the prosecutor’s reference to the
defendant’s opportunity to testify is a fair response to a claim
made by defendant or his counsel,” there is no Fifth Amend-
ment violation. United States v. Robinson, 

, 32
(1988). In Robinson, the defense counsel argued several times
in his closing argument that the government had denied Rob-
inson the opportunity to explain his actions. 

The
prosecutor responded by indicating that Robinson could have
explained himself by testifying. The Supreme Court ruled that
Robinson’s Fifth Amendment Rights were not thereby
infringed because this response did not “treat the defendant’s
silence as substantive evidence of guilt,” but rather answered
the defense’s claim that Robinson’s trial was unfair. 

32.

   [6] Similarly, in this case, the prosecutor merely responded
to Norwood’s implication of investigative misconduct.
Defense counsel implied that there was no evidence that Nor-
wood had used crack cocaine only because the police had
failed to test the box of marijuana blunts. The prosecutor’s
comment was made to defend the police officers’ decision not
to test the marijuana blunts, not to suggest that Norwood’s
silence was substantive evidence of his guilt.

  [7] We will not reverse a lower court’s conviction “ ‘when
a prosecutorial comment is a single, isolated incident, does
not stress an inference of guilt from silence as the basis for
conviction, and is followed by a curative instruction.’ ”
United States v. Smith, 

, 769 (9th Cir. 2002)
(quoting United States v. Tarazon, 

, 1051 (9th
2512               UNITED STATES v. NORWOOD
Cir. 1993)); see also United States v. Foster, 

,
468 (9th Cir. 1993) (recognizing that “there is no Doyle viola-
tion if the district court promptly sustains a timely objection
to a question concerning post-arrest silence, and gives a cura-
tive jury instruction”). In this case, the prosecution’s allegedly
violative comment was a single incident in closing argument,
and as indicated above, served primarily to refute an implied
claim of investigative carelessness. The district court immedi-
ately sustained Norwood’s objection to the comment and pro-
vided a curative instruction. If any error existed on this
record, it was harmless. Based on these facts, we affirm Nor-
wood’s conviction.

   The Fifth Amendment also guarantees a defendant the right
to due process at sentencing. Norwood argues that his sen-
tence, authorized by 21 U.S.C. § 841(b), is cruel and unusual
in violation of the Eighth Amendment and based on an arbi-
trary distinction that violates the Due Process Clause of the
Fifth Amendment. See Chapman v. United States, 

, 465 (1991). Norwood acknowledges that we have previ-
ously addressed this issue in United States v. Harding, 

(9th Cir. 1992). However, he raises the issue in this
appeal because “[n]o issue in the world of federal sentencing
has sparked more controversy or engendered more criticism
than the punishment scheme for crack and powder cocaine.”
Steven L. Chanenson & Douglas A. Berman, Federal
Cocaine Sentencing in Transition, 19 FED. SENT. R. 291 291
(2007).

   [8] Under our precedents, Norwood must show that there
is not even a debatable basis for the distinction between crack
and powder cocaine in order to successfully challenge Con-
gress’ statutory distinction between these two forms of
cocaine base. 

(citing United States
v. Carolene Prods. Co., 

, 154 (1938)). He has
failed to do so.

  In his brief, Norwood cites a series of Special Reports to
Congress provided by the Sentencing Commission for the past
                   UNITED STATES v. NORWOOD                   2513
thirteen years. Although these reports indicate that some of
the alleged differences between crack and powder cocaine
cited by Congress in 1986 have been scientifically disproven,
the reports still suggest that the two forms have distinctive
qualities and that there are reasons for treating the two forms
differently. See United States Sentencing Commission, 2007
REPORT TO CONGRESS: COCAINE AND FEDERAL SENTENCING
POLICY (May 2007).

   [9] As Norwood himself seems to acknowledge, in a case
such as this it is the role of Congress to alter the relevant stat-
utes, and we remain bound by the statutes currently in effect
so long as Congress has a debatable rationale for preserving
its rational-basis distinction. Norwood has also failed to pro-
vide any persuasive rationale for why his sentence should be
considered cruel and unusual under the Eighth Amendment.
Accordingly, we affirm Norwood’s sentence.

C.   Sufficiency of the Evidence

  The standard of review for sufficiency of the evidence to
support a criminal conviction is well established. The
Supreme Court has long advised that a reviewing court is not
required to determine

     whether it believes that the evidence at trial estab-
     lished guilt beyond a reasonable doubt. Instead, the
     relevant question is whether, after viewing the evi-
     dence in the light most favorable to the prosecution,
     any rational trier of fact could have found the essen-
     tial elements of the crime beyond a reasonable
     doubt.

(internal citation omitted).

   To obtain a conviction under § 924(c)(1), the government
must show that the defendant’s possession of the firearm was
“in furtherance” of his drug crime. United States v. Lopez,
2514               UNITED STATES v. NORWOOD

, 1115 (9th Cir. 2007). As we noted in 

, § 924(c)(1) was amended in 1998 to
employ the provision that the firearm be possessed “in fur-
therance of” the drug trafficking crime. This amendment
superceded the previous standard that the offender “use or
carry” a firearm “during and in relation to any . . . drug traf-
ficking crime.” 18 U.S.C. § 924(c)(1) (1994), amended by 18
U.S.C. § 924(c)(1) (Supp. IV 1998). The amendment sought
to broaden the scope of § 924(c)(1) to include more conduct
than actually using or carrying the weapon during the course
of the drug trafficking offense. H.R. REP. NO. 105-344, at 6
(1997). See also 

-14 (detailing the rea-
sons behind the alteration, including Congress’s disapproval
of Bailey v. United States, 

(1995) (defining
“use” to require active employment of a firearm)).

   [10] However, “mere possession of a firearm by an indi-
vidual convicted of a drug crime is not sufficient for a rational
trier of fact to convict” under § 924(c)(1). 

. A conviction is only supported by sufficient evidence
when the facts “reveal a nexus between the guns discovered
and the underlying offense.” United States v. Krouse, 

, 968 (2004). To prove this nexus, the government
must “illustrate through specific facts, which tie the defendant
to the firearm, that the firearm was possessed to advance or
promote the criminal activity.” 

(quoting H.R. REP.
NO. 105-334, at 12 (1997)). Expert testimony indicating that
drug traffickers “generally use firearms to further their drug
crimes” is not sufficient. 

.

   In cases where the underlying drug offense is possession
with intent to distribute, the government has provided ade-
quate evidence of a nexus between the firearm and the drug
crime by showing that the firearm is in the same room and
“within easy reach” of a “substantial quantity of drugs and
drug trafficking paraphernalia.” 

; see
also 

(“Because Lopez’s drug crime
was possession of cocaine with intent to distribute, evidence
                   UNITED STATES v. NORWOOD                 2515
establishing the ready accessibility of the gun while he was in
possession of a distributable amount of cocaine satisfied the
‘in furtherance’ requirement.”). In this case, while the quan-
tity of drugs is smaller and the circumstances establishing a
nexus are not as clear as those in Krouse or Lopez, we cannot
say that “[no] rational trier of fact could have found the essen-
tial elements of the crime beyond a reasonable doubt.” Jack-

.

   [11] The gun at issue in this case was found by the police
only a few feet from evidence that the jury found sufficient
to establish Norwood’s possession of cocaine with intent to
distribute conviction. Specifically, the police found a digital
scale, on which drug residue and Norwood’s fingerprints were
found, and 7.7 grams of cocaine packaged in two “eight ball”
sizes, which both parties stipulated is a commercial amount
that could be sold on the street. In addition, the police first
discovered Norwood lying on top of the mattress where the
gun was hidden, with over $2500 dollars in his pocket, along
with a smaller amount of cocaine, which witnesses testified
could still be considered a commercial amount. Given this
evidence, we affirm the district court’s ruling that “a reason-
able jury could infer that [Norwood] possessed the firearm in
furtherance of the trafficking of crack, specifically to protect
himself and his business.” Order Den. Mot. For J. of Acquit-
tal, United States v. Norwood, No. 06-091, (E.D. Wash.
2007).

  AFFIRMED.