with whom ■ Circuit Judges O’SCANNLAIN, T.G. NELSON, and GRABER join, Dissenting.
Today the majority reaches a claim that should not be reached' — whether the Nevada Supreme Court could or did cure the “depravity of mind” aspect of the “torture, depravity of mind and mutilation” aggravating circumstance — and holds, without warrant, that a state supreme court may not apply a narrowing construction to an unconstitutionally vague instruction and determine that it is supported by the evidence as applied, when the penalty-phase factfinder is a jury instead of a judge.
Neither this issue nor its companion, whether substantial evidence supports the aggravator, should be reached because the effect of the court’s other decision — to treat Valerio’s briefing as a request for a broadened Certificate of Appealability (COA), and to grant that request — is to revive a number of guilt-phase claims. Some of these claims are unexhausted. This means that Valerio’s petition is now a mixed petition, subject to dismissal under Rose v. Lundy, 455 U.S. 509, 522, 102 S.Ct. 1198, 71 L.Ed.2d 379 (1982). The majority recognizes this in its remand of remaining claims, noting that the petition must be dismissed' (or stayed) if unexhausted claims are not dropped. But if the petition is mixed, it is mixed for all claims, not just some of them. The aggravating circumstance claim also should not be reached because it is a sentencing issue that may *780go away given reinstatement of substantial guilt-phase claims. While we may decide a sentencing issue first, we do not have to and, in my view, the court should not do so particularly where (as here) the issue involves an important question of constitutional law that affects how state appellate courts review state court judgments.
Beyond this, the majority’s holding that a state appellate court lacks authority to cure an unconstitutional instruction by a narrowing construction whenever the sentence is determined by a jury is simply wrong. Clemons v. Mississippi 494 U.S. 738, 110 S.Ct. 1441, 108 L.Ed.2d 725 (1990), says that an appellate court has that authority and nothing said in Walton v. Arizona, 497 U.S. 639, 110 S.Ct. 3047, 111 L.Ed.2d 511 (1990), overruled on other grounds by Ring v. Arizona, — U.S. -, 122 S.Ct. 2428, 153 L.Ed.2d 556 (2002), is to the contrary. Nor, if I had to get there, do I believe that the Nevada Supreme Court failed to scrutinize this case closely enough; while its analysis may not be perfectly articulated, I respect that court’s citation to its own precedent, Robins v. State, 106 Nev. 611, 798 P.2d 558 (1990), which indicates to me that the court applied a narrowing construction and determined that the evidence supplied a cogent basis for the jury’s finding of the aggravating circumstance limited in scope to the permissible construction.
I therefore dissent both from the discussion, and the decision, in Part II.
I would also come out differently on whether to treat Valerio’s briefing as a request to broaden his COA. However, unlike .the .decision on the constitutional issue, the decision on this question is quite limited because it can only apply to petitioners who appear to have been caught in the middle during the six months between our decision on June 23, 1998, in United States v. Cruz-Mendoza, 147 F.3d 1069 (9th Cir.1998) (Cruz-Mendoza I), and the effective date of Circuit Rule 22 — 1 (d), January 1, 1999. Still, I disagree that Valerio was actually caught in the middle. He does not purport to have relied on Cruz-Mendoza I, nor could he have. Nothing had happened in Valerio’s appeal as of December 31, 1998, when United States v. Cruz-Mendoza, 163 F.3d 1149 (9th Cir.1998) (Cruz-Mendoza II), amended the opinion in Cruz-Mendoza I in light of Rule 22-l(d). Valerio was then on notice that briefing would no longer be treated as a request for a broadened COA and that Rule 22-l(d), which states that the court of appeals will not consider uncertified issues unless a request for broadened certification is made and granted, had been adopted to clarify the procedure that would apply to COAs which had been partly granted and partly denied by the district court. Although the thirty-five day period provided in the Rule for making such a request had passed, prospectively Valerio had plenty of time to request a broadened certificate after Cruz-Mendoza I was withdrawn and Rule 22-1 (d) became effective the first of the year, and before his brief was filed on May 12, 1999. As United States v. Zuno-Arce, 209 F.3d 1095 (9th Cir.2000), amended by 245 F.3d 1108 (9th Cir.2001), reasons similarly, I would not overrule it. Accordingly, I dissent from Part III as well.
I
A
In my view, the majority’s opinion puts the cart before the horse by starting with Valerio’s claim arising out of the “torture, depravity of mind, or mutilation of the victim” aggravating circumstance found by the jury. Instead, given the way the majority answers it, the foundational question turns out to be whether a broadened COA *781should be granted, because a mixed petition is created by virtue of its answer. We should not review a mixed petition on the merits.
The district court denied three of Valer-io’s claims outright and granted a COA on each. Valerio pursues two of these claims on appeal (Claim 14, vague instruction on aggravating circumstance in penalty phase; and Claim 15, insufficiency of the evidence of torture and mutilation). The district court also dismissed a number of-claims on the ground of abuse of the writ or procedural default. It denied a COA as to these rulings, however the majority broadens Valerio’s COA to include them. Having granted the COA, the majority reverses the district court’s procedural rulings and remands for the district court to resolve the affected claims on the .merits. But three of these claims are unexhausted. The majority recognizes that its decision to reverse the district, court’s procedural rulings has produced a mixed petition under Rose v. Lundy, and that the district court must dismiss or stay the petition unless the unexhausted claims are deleted. See op., supra at 768 and 770-71. Nevertheless, it reaches and resolves the merits of the aggravating circumstance claim, which is part of the same petition.
Because there are parts and subparts to contend with, it is easier to illustrate the problem by supposing a petition that consists of Claims A, B and C. Claim A is exhausted, was resolved on the merits, and is certified by the district court. Claims B and C were dismissed on procedural grounds, but the procedural rulings are not certified; substantively, Claim B is not exhausted although Claim C is. There is no mixed petition at this point because Claims B and C are out of the picture. On appeal, we grant a broadened COA as to Claims B and C and reverse the district court’s procedural rulings. Claims B and C are now revived on the merits. Because Claim B is not exhausted, the petition is mixed. The mixed petition includes Claims A, B and C — not just Claims B and C. All of them must be dismissed or stayed while Claim B is exhausted, unless Claim B is dropped.
I realize that exhaustion is not jurisdictional, and that courts of appeals may review the merits of a petitioner’s claim in unusual circumstances even though some claims are unexhausted. However, exceptions to the general rule exist primarily when the state has waived the exhaustion requirement or when the unexhausted claim lacks merit and can easily be resolved. See, e.g., Strickland v. Washington, 466 U.S. 668, 684, 104 S.Ct. 2052, 80 L.Ed.2d 674 (1984) (exhaustion rule requiring dismissal of mixed petitions, though to be strictly enforced, is not jurisdictional; there, unexhausted claim lacked merit); Granberry v. Greer, 481 U.S. 129, 135-36, 107 S.Ct. 1671, 95 L.Ed.2d 119 (1987) (no-nexhaustion defense is waivable; there,.it wasn’t raised until appeal and in that event court should determine whether interests of justice would be better served by addressing merits or requiring additional state proceedings); Acosta-Huerta v. Estelle, 7 F.3d 139, 142 (9th Cir.1993) (noting jurisdiction to consider unexhausted claims in mixed petition if claims “clearly do not rise to the level of alleged deprivations of constitutional rights”) (quoting James S. Liebman, Federal Habeas Corpus Practice and Procedure § 9.3(b), at 122 (1988)). There is no recognized exception for reviewing one among several exhausted claims, just because it may have merit or has been certified. Otherwise, if one of several exhausted claims could be resolved even though the petition is mixed, the rule requiring dismissal' of mixed petitions would be meaningless. That is the case here: a single, exhausted issue has been cherry-picked for review on the merits. *782Moreover, the favored issue has considerable constitutional importance and raises serious federalism concerns. It is not dis-positive and does not dictate the outcome of remaining claims (even as to sentencing, for there is an unresolved claim that appellate counsel was ineffective in failing to raise the aggravating circumstance issue on direct appeal). In short, the petition is mixed , and all claims must be remanded for dismissal, stay, or deletion.
A second reason that I would not review the aggravating circumstance issue is that it is a sentencing issue that we may never have to deal with. Among other things, Valerio’s guilt-phase claims challenge the effectiveness of both trial and appellate counsel, the .prosecutor’s compliance with Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963), and prejudicial admission of evidence, all of which the majority regards as making a substantial showing of the denial of a constitutional right. 28 U.S.C. § 2253(c)(2). If Valerio prevails on any one of them, his conviction would be invalidated and sentencing issues avoided. In these circumstances, it makes a good deal of sense to defer consideration of sentencing issues until issues relating to the conviction are settled. We have done so before, see, e.g., Fields v. Woodford, 281 F.3d 963, 981 (9th Cir.2002), and I believe that we should do so now. Prudence, in addition to Rose v. Lundy, counsels in favor of restraint in these circumstances.1
Third and finally, I would not consider the aggravating circumstance claim as posed by-the majority, because the parties never developed the issue in the way that the majority frames and decides it.
B
Valerio does not argue that “Walton appellate factfinding [is] unavailable when [the] penalty-phase factfinder was a jury,” op., supra at 758; indeed, Valerio acknowledges that under Walton v. Arizona, 497 U.S. 639, 110 S.Ct. 3047, 111 L.Ed.2d 511 (1990), Lewis v. Jeffers, 497 U.S. 764, 110 S.Ct. 3092, 111 L.Ed.2d 606 (1990), and Maynard v. Cartwright, 486 U.S. 356, 108 S.Ct. 1853, 100 L.Ed.2d 372 (1988), a vague aggravating circumstance’ may survive' a constitutional challenge where a sufficiently narrow construction is adopted and applied by a state appellate court.2 Instead, he contends that the state courts did not cure the unconstitutional impact of the vague aggravator in his case because there was insufficient evidence of torture, mutilation or other serious and depraved physical abuse beyond the act of killing itself to avoid the unconstitutional application of the vague aggravator; the Nevada Supreme Court and the federal district court failed to- apply the narrowing construction to the aggravator such that it remains unconstitutionally vague; the Nevada Su-*783prerae Court has inconsistently applied its limiting construction; and the state supreme court lacked authority under state law to make the findings necessary to uphold the sentence of death or the aggravating circumstance upon which it is based. These arguments can be addressed summarily.3 However, the majority ventures out on its own to hold (a) that neither Walton nor any other authority allows a state appellate court to apply a narrowing construction to an unconstitutional instruction when the penalty-phase factfinder is a jury; and (b) that even if Walton could be used to cure an unconstitutionally vague aggravating-circumstance jury instruction, the Nevada Supreme Court did not do its job right by providing “close appellate scrutiny.”
I would not go on this venture at all but, were I to, I would question each step of the way.
l
The majority assumes that Walton controls,4 but characterizes Walton as offering a different way (in addition to reweighing and harmless error review that the Supreme Court sanctioned in Clemons) for a state appellate court to affirm a death sentence after providing a narrowing construction of an aggravating circumstance. The opinion describes this as “de novo factfinding.”. Op., supra at 758-59. But I don’t think so. Rather, Walton simply carries forward the Clemons options for a state appellate court when faced with an unconstitutionally vague aggravator: either determine whether the existence of the aggravating circumstance as properly defined is supported by the evidence — i.e., harmless error review — or reweigh. Walton, 497 U.S. at 653-54, 110 S.Ct. 3047 (so stating, citing Clemons ).5
*784For this reason alone the majority’s conclusion that Walton does not extend to jury determinations cannot stand, because that conclusion necessarily depends on the premise that Walton permits de novo “appellate factfinding.” But harmless error analysis — although it assumes an independent review of the record — is not de novo factfinding. Rather, a state appellate court’s affirming a death sentence after the jury has been instructed to consider an invalid factor simply determines that the result would have been the same had the aggravating circumstance been properly defined. Stringer v. Black, 503 U.S. 222, 230, 112 S.Ct. 1130, 117 L.Ed.2d 367 (1992); Clemons, 494 U.S. at 754, 110 S.Ct. 1441. This, as the Court put it in Clemons, is “a routine task of appellate courts.” Clemons, 494 U.S. at 748-49, 110 S.Ct. 1441.
The majority’s conclusion also cannot stand on its other central premise — that a state appellate court’s ability to cure instructional error in an aggravating circumstance stems only from Walton. It does not. It also stems from Clemons, Maynard, and Godfrey v. Georgia, 446 U.S. 420, 100 S.Ct. 1759, 64 L.Ed.2d 398 (1980). Read together, these opinions make it clear that state appellate courts may cure unconstitutionally vague aggravating circumstances whether the error occurred in a judge’s decision, or in a jury instruction.
The petitioner in Godfrey was sentenced to death by a jury based on a verdict finding that the offense of murder was “outrageously or wantonly vile, horrible and inhuman.” The aggravating circumstance permitted a person to be sentenced to death if the jury found beyond a reasonable doubt that the offense “was outrageously or wantonly vile, horrible or inhuman in that it involved torture, depravity of mind, or an aggravated battery to the victim.” Even though the Georgia Supreme Court had previously upheld death sentences based on the presence of torture or an aggravated battery, in this case it affirmed solely on the basis of the jury’s finding that the offense was “outrageously or wantonly vile, horrible and inhuman.” The United States Supreme Court held that this application of the aggravating circumstance was unconstitutional, because a finding that a murder was “outrageously or wantonly vile, horrible and inhuman” is standardless and unchanneled. It reversed because the jury’s uncontrolled discretion was “in no way cured by the affir-mance of those sentences by the Georgia Supreme Court.” Godfrey, 446 U.S. at 429, 100 S.Ct. 1759. In so holding, the Court noted that the circumstances of the case did not satisfy the criteria previously outlined by the Georgia Supreme Court (torture and aggravated battery), that the Georgia Supreme Court did not take a different view of the evidence, and that the Georgia Supreme Court could not be said to have applied a constitutional construction of the remaining phrase in the aggra-vator, involving depravity of mind, because the petitioner’s crimes did not reflect a consciousness materially more “depraved” than that of any other person guilty of murder. Thus, the Supreme Court did not reverse because the state appellate court could not cure an unconstitutional aggravating-circumstance instruction, but because it did not; “that court failed to apply its previously recognized limiting construction of the aggravating circumstance.” Maynard, 486 U.S. at 363, 108 S.Ct. 1853 (explaining what went wrong in Godfrey).
*785Much the same thing happened in Maynard. It, too, involved a jury determination of the death penalty based on three aggravating circumstances. The language of one of them — “especially heinous, atrocious, or cruel” — gave no more guidance than the language that the jury returned in its verdict in Godfrey. The Oklahoma Supreme Court concluded that the jury’s verdict that the murder was especially heinous, atrocious or cruel was supportable, but the United States Supreme Court reversed because the state appellate court made no attempt to cure the constitutional infirmity of the aggravating circumstance. Maynard, 486 U.S. at 364, 108 S.Ct. 1853. Again, the Court did not fault the process. Id. at 365, 108 S.Ct. 1853 (noting that since the state supreme court’s decision, the Oklahoma appellate courts had restricted the aggravating circumstance to those murders in which torture or serious physical abuse is present). Nor did it intimate in any way that an appellate court could not cure the constitutional infirmity of the aggravating circumstance simply because it had been found by a jury.
Clemons was also a jury case. Clemons argued that it was constitutionally impermissible for an appellate court to uphold a death sentence imposed by a jury that has relied in part on an invalid aggravating circumstance. This is basically the same proposition that the majority accepts, but the Supreme Court rejected. The Court held that an appellate court may weigh the valid aggravating circumstances against mitigating circumstances without the assistance of written jury findings, or it may find that the error which occurred during the sentencing process was harmless. Clemons, 494 U.S. at 748-54, 110 S.Ct. 1441. In Clemons itself, the Court could not tell what the Mississippi Supreme Court intended by its harmless error analysis. But the Court made clear that harmless error analysis is available, and that it is possible for a state appellate court to determine that' the failure to instruct properly on an aggravating circumstance was harmless error if the result would have been the same had the 'aggravating circumstance been properly defined. Id. at 754 & n. 5, 110 S.Ct. 1441 (emphasizing that in Johnson v. State, 486 U.S. 578, 108 S.Ct. 1981, 100 L.Ed.2d 575 (1988), where the Mississippi Supreme Court had decided to remand to a sentencing jury, the United. States Supreme Court “did not hold that the Mississippi Supreme Court could not have applied harmless-error analysis”).
Walton says nothing to the contrary. The majority infers that Walton cannot be used to cure an unconstitutionally vague aggravating-circumstance jury instruction from the fact that the Supreme Court “found” Maynard and Godfrey “not controlling” because the death sentences in those cases had been imposed by juries. Op., supra at 757-58.6 That’s true, so far as it goes, but misses the point of the discussion in Walton. There, the trial judge found two aggravating circumstances, that the murder was “especially heinous, cruel, or depraved,” and that it was done for pecuniary gain. The Arizona Supreme Court had previously given a narrowing construction to “especially hei*786nous, cruel, or depraved,” but the trial judge’s finding that the special circumstance existed was articulated only in the vague statutory language. The petitioner argued that this failed to pass constitutional muster for the same reasons that the Court found Oklahoma’s and Georgia’s aggravating circumstances invalid in Maynard and Godfrey. The Supreme Court disagreed. It explained that the two prior cases were different because in both, the jury was instructed only in the bare terms of the statute and “in neither case did the state appellate court, in reviewing the propriety of the death sentence, purport to affirm the death sentence by applying a limiting definition of the aggravating circumstance to the facts presented.” Walton, 497 U.S. at 653, 110 S.Ct. 3047. In other words, if a jury is the factfinder and is improperly instructed in the bare terms of a vague aggravating circumstance, the death sentence has to be reversed unless the state appellate court itself determines that the evidence supports the existence of the aggravating circumstance as properly defined. However, judges (unlike jurors who have to be instructed on the law) are presumed to know and to apply an aggravating circumstance according to its valid, judicially narrowed definition. Thus, if the state appellate courts have adopted a narrowing construction of the aggravating circumstance, as the Arizona Supreme Court had done with respect to “especially cruel,” neither reversal nor cure is required regardless whether the statutory definition is vague when a judge makes the finding rather than a jury. But even if a judge fails to apply a narrowing construction or applies an improper construction, the Court indicated that reversal is still not required because the state appellate court may nevertheless cure that error just as Clemons provides. Put differently, Wal-ta does not take Clemons review away when the factfinder is a jury; it extends it to a judge when the judge acts like a jury by finding an aggravating circumstance that is based on a constitutionally wrong interpretation of law.
If there were any doubt whether Walton left appellate courts able to salvage a death sentence based in part on an invalid aggravating circumstance when the penalty phase factfinder is a jury (which I don’t think there is), Stringer, which came down after Walton, should dispel it. Stringer also involved a jury finding based on an invalid aggravating factor and it also acknowledges the availability of an appellate cure by way of harmless error analysis. Stringer, 503 U.S. at 230, 112 S.Ct. 1130 (noting that “[i]n order for a state appellate court to affirm a death sentence after the sentencer was instructed to consider an invalid factor, the court must determine what the sentencer would have done absent the factor”).
Nor does Pertgen v. State, 110 Nev. 554, 875 P.2d 361 (1994), abrogated on other grounds by Pellegrini v. State, 34 P.3d 519 (Nev.2001), upon which the majority relies, support its conclusion that a state appellate court may not cure an unconstitutionally vague aggravating circumstance found by a jury, or indicate that “[t]he Nevada Supreme Court itself now agrees that the Walton appellate factfinding procedure is not available when the penalty-phase fact-finder was a jury,” as the majority says that it does. Op., supra at 758. After observing in the passage cited by the majority that Walton is distinguishable because a judge is presumed to know the law and apply it constitutionally, whereas Pert-gen’s death sentence was imposed by a jury which is supposed to be correctly instructed,7 the Nevada Supreme Court went on to state:
*787Our inquiry does not end at this juncture, however. In Clemons v. Mississippi, the United States Supreme Court confirmed that reweighing and harmless error analyses, though not required, are constitutionally permissible under appropriate circumstances. Likewise, it is permissible for us to remand for resen-tencing when the circumstances necessitate such action. We have elected to follow each of these alternatives under appropriate circumstances.
Pertgen, 875 P.2d at 366 (internal citations omitted). Thus, all that the Nevada Supreme Court did in Pertgen was to recognize that it has discretion to cure or to remand. While the United States Supreme Court has said that state appellate courts may cure an unconstitutionally vague aggravating circumstance found by a jury, of course it has never said that state appellate courts must do so. See Clemons, 494 U.S. at 754 n. 5, 110 S.Ct. 1441 (noting that harmless error analysis is alternative to remand). Rather than line up with the majority’s view of Walton, the Pertgen court actually performed a harmless error analysis but concluded that the error in Pertgen’s case wasn’t harmless beyond a reasonable doubt. Be this as it may, the majority has now held that Walton does not allow a state appellate court to apply a narrowing construction to an unconstitutional instruction when the penalty phase factfinder has been a jury. To me, this breaks new ground. Therefore, in addition to everything else, today’s decision implicates Teague v. Lane, 489 U.S. 288, 109 S.Ct. 1060, 103 L.Ed.2d 334 (1989), because it announces a new rule in a federal habeas corpus proceeding.
For all these reasons, I would not reach the issue whether the Nevada Supreme Court could cure the “torture, depravity of mind and mutilation” aggravating circumstance, but if forced to, I would hold that the Nevada Supreme Court could apply a narrowing construction to the unconstitutionally vague instruction in this case and determine that. the aggravating circumstance found by the jury is supported by the evidence as applied.
2
Alternatively, the majority holds that the Nevada Supreme Court failed to give “close appellate scrutiny” to its application of the narrowing definition that it adopted for the “torture, depravity of mind' and mutilation” ' aggravating circumstance. This comes from Stringer, which requires “close appellate1 scrutiny of the import and effect of invalid aggravating factors to implement the well-established Eighth Amendment requirement of individualized sentencing determinations in death penalty cases.” Stringer, 503 U.S. at 230, 112 S.Ct. 1130. While it may have been more helpful had the Nevada Supreme Court’s analysis been more detailed, this is not a complicated case and I have no trouble understanding what the court did and why.
I assume by its citation to Robins that the Nevada Supreme Court considered and rationally applied its own recent precedent. Thus, the court concluded that the “torture, depravity of mind and mutilation” aggravating circumstance was not based solely upon a “depravity of mind” aspect as it was in Godfrey, but also on torture and serious physical abuse. Nevada’s aggravating circumstance contains *788such limiting language and is construed “as requiring torture, mutilation or other serious and depraved physical abuse beyond the act of killing itself, as a qualifying requirement to an aggravating circumstance based in part upon depravity of mind.”8 Robins, 798 P.2d at 570. The evidence supplied “a cogent basis” for the jury’s finding of the aggravating circumstance limited in scope by this construction. The reason is: “evidence that Ms. Blackwell was stabbed more than forty-five times, had ‘defensive wounds’ on her hands and arms, and died not from one wound but from all wounds combined, satisfies us that she was subjected to torture and/or serious physical abuse before she died.” Order Dismissing Appeal at 1 n. 2 (Nev.S.Ct. Jan. 24, 1992). This shows me that the Nevada Supreme Court conducted an independent review of the evidence and concluded that the aggravating circumstance instruction was not unconstitutionally vague as applied.
While reasonable minds can certainly disagree about the disposition’s clarity, I question how the state’s highest court can fall short of “close” appellate scrutiny simply by stating that it “agreed” with the trial judge that the murder involved “torture (or serious physical abuse)” when the trial judge had only discussed torture, and that it was “satisfied” that this is what the evidence showed. Op., supra at 759. I should think it unremarkable that torture encompasses “serious physical abuse” when, as here, the victim was stabbed forty-five times by a knife, mostly in patterns of eight, on targeted parts of her body.9 Nor would I fault the Nevada Supreme Court for stating that the evidence “satisfies us” that the victim was subjected to torture and physical abuse. Op., supra at 758-59. It is supposed to be satisfied that the evidence supports the existence of the aggravating circumstance as properly defined. See Walton, 497 U.S. at 654, 110 S.Ct. 3047 (citing Clemons). Nothing in the Constitution requires us to disturb that conclusion. While the court could have said “convinces us” or it could have said “persuades us sufficiently,” I am satisfied that the Nevada Supreme Court believed that torture and/or serious physical abuse had been proved. While it also could have said “beyond a reasonable doubt,” I do not doubt that the state’s highest court knows what the standard is in a criminal case. Finally, it is hard for me to understand the majority’s quarrel with the Nevada Supreme Court’s conclusion that the victim was tortured or seriously physically *789abused even though she wasn’t killed by the first stab but from all forty-five of them. To me, stabbing a person forty-two or —three or —four times more than necessary to kill is not at all inconsistent with •the narrowed version' of the instruction that requires abuse “beyond the act of killing itself.” But regardless, how Nevada interprets its own limiting construction is a matter of state law that is not cognizable on federal habeas review. See Jeffers, 497 U.S. at 780, 110 S.Ct. 3092. Therefore, whether we think it is a sensible view of state law, or not, is immaterial.
In any event, the majority has concluded that the Nevada Supreme Court fell short of the mark. Having done so, I would be guided by what the Supreme Court did in Richmond v. Lewis, 506 U.S. 40, 113 S.Ct. 528, 121 L.Ed.2d 411 (1992). There, it held that the Supreme Court of Arizona did not cure a sentencing judge’s error in giving weight to an unconstitutionally vague aggravating factor because two justices who concurred in affirming the sentence did not actually perform a new sentencing calculus, as required for reweighing. The Court returned the case to the district court “to enter an order granting the petition for a writ of habeas corpus unless the State of Arizona within a reasonable period of time either corrects the constitutional error in petitioner’s death sentence or vacates the sentence and imposes a lesser sentence consistent with law.” Id. at 52, 113 S.Ct. 528. Similarly, if the only deficiency is that the Nevada Supreme Court failed to give close enough scrutiny to satisfy this court, Nevada courts should have another crack at doing so.
3
Assuming that I got there, my own harmless error determination would also differ from the majority’s. ■ The majority opts to apply the harmless error standard in Brecht v. Abrahamson, 507, U.S. 619, 113 S.Ct. 1710, 123 L.Ed.2d 353 (1993) (substantial and injurious effect or influence) because of its view that the Walton analysis, is unavailable. I would follow the Supreme Court’s direction in Jeffers to adhere to the Jackson v. Virginia, 443 U.S. 307, 99 S.Ct. 2781, 61 L.Ed.2d 560 (1979), rational factfinder standard. Jeffers, 497 U.S. at 781, 110 S.Ct. 3092. Also, Valerio concedes that Jackson is the applicable standard. Either way, I cannot say that the Nevada Supreme Court got it wrong or that any rational factfinder would have found anything but torture or serious physical abuse (mutilation). In short, the error was harmless.
Karen Blackwell was twenty-seven years old when she went to Valerio’s hpuse on September 19, 1986. Ten days later, her partially clothed body was found in the back seat of a car parked at a Las Vegas apartment complex.
Blackwell had been stabbed forty-five times, had blunt trauma lacerations to the right side of the head, and had “defensive” wounds or cuts in the left upper arm, and right hand. Most of the wounds occurred in 'groups of eight. There were eight stab wounds on the top of her head, in a cluster of about two inches. These wounds penetrated the skin but did not go into the skull. Blackwell was stabbed eight times on the front of her neck, again in a small cluster, and eight times in a cluster on the back of her neck. Valerio also stabbed Blackwell eight times (in an arc) in the right breast, and eight times in the left breast. Then there were three stab woúnds in the abdomen, leading down to one stab wound in the vaginal area.
When found, Blackwell’s body was wrapped in Valerio’s bedding. Blood was found in Valerio’s bedroom. Blackwell’s *790keys and an address book with her name and phone number were in the pockets of Valerio’s jacket (seized in a search of his house).
Based on this evidence, I would hold that a rational factfinder could have found that Valerio subjected Blackwell to torture or serious physical abuse. See, e.g., Jones v. State, 113 Nev. 454, 937 P.2d 55, 68 (1997) (evidence of thirty-five wounds, including a cluster of seven to the victim’s right breast, is mutilation). Neither do I have any doubt that any reasonable juror who heard the testimony and saw the exhibits would find otherwise. Therefore, in my view, the Nevada Supreme Court could reasonably have concluded that the offense Valerio committed involved torture or serious physical abuse beyond the act of killing itself, and its conclusion is rationally supported by the evidence.
II
I also part company with the majority’s approach to broadening the Certificate of Appealability. The chronology shows why Valerio’s briefing should not count as a request to expand his COA, so I recite it completely.
Since April 24, 1996, appeals from dismissal of habeas corpus petitions have been governed by the certificate of appeal-ability requirements of AEDPA. 28 U.S.C. § 2253(c). However, AEDPA simply provides that an appeal may not be taken from a final order in a habeas corpus proceeding unless “a circuit justice or judge” issues a COA that indicates the specific issues upon which the petitioner has made a substantial showing of the denial of a constitutional right. We decided early on that requests for a COA could be made in the first instance to the district court, United States v. Asrar, 116 F.3d 1268, 1270 (9th Cir.1997), and 1998 amendments to Rule 22(b) of the Federal Rules of Appellate Procedure, effective December 1, 1998, assumed the same thing. Amended Rule 22(b)(1) also provided that, “[i]f the district judge has denied the certificate, the applicant may request a circuit judge to issue the certificate.” But there was no specific provision in statute or rule for what should happen when the district court grants a COA in part and denies it in part.
We first considered how to treat such cases in Cruz-Mendoza I. The petitioner there had filed a § 2255 petition, which the district court denied. He sought a COA in the district court on all issues, but it was not granted on one of them. He did not separately request a COA from a motions panel of our court on the uncertified issue, but briefed it and requested in his opening brief that a COA be granted. We held that, “in the interest of efficiency, where a district judge has issued a COA on some but not all of the issues, we will treat the briefing of an uncertified issue as a request for a COA and first decide whether one should issue.” Cruz-Mendoza I, 147 F.3d at 1074 (footnote omitted). This decision was rendered on June 23,1998.
The district court dismissed Valerio’s § 2254 petition on August 19, 1998. He filed a notice of appeal September 18, 1998, and on October 15, 1998, the district court granted a COA as to Ground 14 (vague instruction on aggravating circumstance in penalty phase) and Ground 15 (insufficiency of the evidence on torture and mutilation) but otherwise denied it.10
The scenario in Cruz-Mendoza I highlighted the need for a procedure to handle *791situations where the district court partly denies a request for a COA. After a three-month period of notice and comment,' Circuit Rule 22-1 (d) was adopted in December 1998 to deal with the problem.- It had an effective date of January 1, 1999. Rule 22-l(d) states that the “court of appeals will not consider uncertified issues unless petitioner first seeks, and the court -of appeals grants, broader certification.” It then tells petitioners that those desiring broader certification must file a separate motion, with reasons, within thirty-five days of entry of the district court’s order denying a COA. Valerio does not dispute that he had notice of the Rule.
Stating that Rule 22 — 1(d) was intended to clarify how cases should be handled in which the district court had declined to certify some of the issues, the Cruz-Mendoza panel amended Cruz-Mendoza I on December 31, 1998. Cruz-Mendoza II deleted that part of Cruz-Mendoza I which had held that when a district judge has issued a COA on some but not all issues, briefing of an uncertified issue would be treated as a request for a COA. Cruz-Mendoza II, 163 F.3d at 1149.
Valerio requested and received a number of extensions after January 1 for filing his opening brief on appeal. However, he did not request that the COA be broadened. He filed his opening brief May 12, 1999. The brief does not request a COA on uncertified issues, but discusses them.
In its answering brief the state asserted that Valerio’s arguments with respect to procedural default and abuse of the writ should not be considered because they were not certified. Valerio responded that he had made these arguments in the district court, hence it would not be unfair to the state for them to be considered by this court; that AEDPA is inapplicable to his petition; and that regardless, he could show the denial of a constitutional' right so he meets the AEDPA standard.
After oral argument, the panel provided the parties a tentative decision and an opportunity to respond to it. The tentative disposition indicated that AEDPA applies to the petition, and that the court would not reach uncertified issues bn which Valerio had failed to request' a broadened COA. Valerio’s response did not mention or challenge the refusal to consider uncertified issues. Nor did Valerio’s response request that the COA be expanded.
After the decision was filed, Valerio filed a petition for rehearing which argued for the first time that as of October 16, 1998, when the district court granted in part and denied in part his request for a COA, this court allowed a petitioner to brief uncerti-fied issues and to construe that briefing as a request for certification on those issues.11 He pointed out that the thirty — five days allowed in the Rule would have expired on November 20, 1998 — before the Rule’s effective date. In these circumstances, he contended that application of Rule 22 — 1(d) produces a harsh and unjustified result, and violates due process, by penalizing him for failing to comply with a rule that was not in' existence at the time he would have been required to comply. However, Valer-io did not indicate that he had relied on Cruz-Mendoza I, did not argue that his briefing should be construed as a request for certification, and did not request a broadened certification or give1 reasons why it should be granted.
Absent any request in any form, I do not believe that the court has any obligation *792sua sponte to determine if uncertified issues should be considered. Neither do I believe that it was impracticable for Valer-io himself to make a request, and to give reasons, for broadening the certification. He knew that regardless of what we held in Cruz-Mendoza I, Cruz-Mendoza II indicated that as of December 28, 1998, this court would no longer consider the mere briefing of an issue as a request for an expanded COA. This was four months before Valerio’s opening brief was filed: Cruz-Mendoza II came down December SI, 1998; his opening brief was not filed until May 12, 1999. He could not possibly have relied on the unamended version of Cruz-Mendoza, and does not claim that he did. Neither does he claim ignorance of Cruz-Mendoza II. In short, Valerio had plenty of time to ask this court to consider uncertified issues, but never did.
Valerio has offered no explanation for failing to ask this court to consider uncerti-fied issues. AEDPA requires a COA. He only obtained part of what he asked for from the district court. This court cannot review uncertified issues. So he had to get permission, somehow. AEDPA prescribes no particular procedure. Cruz-Mendoza I — which did — said that briefing would suffice, but it was withdrawn long before Valerio filed his brief.
Rule 22-1 (d) replaced Cruz-Mendoza I and restates the obvious: a petitioner must seek permission to pursue uncertified issues from the court of appeals, and certification must in fact be granted. As we observed in Hiivala v. Wood, 195 F.3d 1098, 1103 (9th Cir.1999), “ § 2253 must limit appellate review to issues specified in the COA because, if it did not, allowing a habeas petitioner to raise uncertified issues would render meaningless the specification language of § 2253(c)(3).” In this respect, Rule 22-l(d) is a procedural device that opened an avenue for petitioners to seek a broader certification from the court of appeals that does not exist in AEDPA. The fact that Rule 22 — 1(d) also sets a time frame that had passed in Valer-io’s case when the Rule became effective does not shield him from the fundamental point that an issue has to be certified to be considered. The heart of the Rule is not the time limit; time limits are, after all, routinely extended and grace periods are allowed. The heart of the Rule is that “the court of appeals will not consider uncertified issues unless petitioner first seeks, and the court of appeals grants, broader certification.”
Neither this post-AEDPA reality, nor the timing requirements of Rule 22 — 1(d), attached new legal consequences to anything that Valerio had completed before it was enacted; nothing had been done on this appeal before Rule 22-l(d) became effective. The normal practice in these circumstances is to apply a procedural rule to pending cases when doing so is “just and practicable.” See, e.g., Order of April 23, 1996, West Federal Civil Judicial Procedure and Rules 442 (2002) (amendments to the Federal Rules of Appellate Procedure “shall govern all proceedings in appellate cases thereafter commenced and, insofar as just and practicable, all proceedings in appellate cases then pending”); Landgraf v. USI Film Prods., 511 U.S. 244, 275, 114 S.Ct. 1483 (1994) (retroactive application of new procedural rules does not raise due process concerns where application is just and practicable); Volkswagenwerk Aktiengesellschaft v. Church, 413 F.2d 1126, 1127-28 (9th Cir.1969) (same). Indeed, in Hiivala, 195 F.3d at 1103, we stated that “Circuit Rule 22-1 and the Advisory Committee Note became effective before this case was submitted for decision. It would appear, therefore, that we should apply the Rule to Hiivala’s appeal.” This is what we held in Zuno-*793Arce, and its reasoning is persuasive. See Zuno-Arce, 209 F.3d at 1100-01.
Applying the Rule is practicable. Although it certainly would have been impossible for Valerio to ask this court for a broader certification within thirty-five days of the district court’s order because he did not know that he was supposed to, this changed as of December 31, 1998. As of then he knew for sure that he had to seek broader certification apart from briefing. Valerio suggests no reason why it was impracticable to do so. Instead, Valerio chose to ignore both Cruz-Mendoza II and this court’s statement in Rule 22-1 (d) that it would not consider uncertified issues, and to brief uncertified issues anyway without, even then, acknowledging that the issues were uncertified or requesting that they be certified.
In these circumstances I do not believe that it is unjust to decline to treat briefing as the functional equivalent of a request to broaden the COA. That option was withdrawn four months earlier, and therefore could engender no expectations. Valerio and amicus now argue that injustice will result because the uncertified issues have merit. But this cannot be the proper measure, for then we would always consider issues that have been waived if they are meritorious but wouldn’t if they aren’t. This is not our practice. See, e.g., Parrino v. FHP, Inc., 146 F.3d 699, 704 (9th Cir.1998); London v. Coopers & Lybrand, 644 F.2d 811, 814 (9th Cir.1981).
The majority’s focus on the absence of direction in Rule 22-1 (d) to a petitioner in Valerio’s position seems misplaced to me, for it leads them to conclude that it was not unreasonable for Valerio to assume that the Rule did not apply to him — particularly, as the opinion states, “given that, prior to the adoption of the Rule, Cruz-Mendoza I had specifically approved briefing to the court of appeals as a mechanism for seeking an expanded COA.” Op., supra at 765. However, I do not see how this can be so in light of the demise of Cruz-Mendoza I four months before Valerio’s briefing was submitted. In sum, Valerio made no request for a broadened COA. After Cruz-Mendoza II, there was no basis for him to assume that briefing would be treated as a request for broader certification. Valerio knew this. He has not offered any compelling reason why Rule 22 — 1(d) could not practicably and justly be applied to petitioners, such as he, who had submitted no briefing in reliance on Cruz-Mendoza I. Far more than thirty-five days elapsed, even if Valerio’s briefs should be treated as a viable request. Thus, for the reasons explained in Zuno-Arce, which I would not overrule, I would not consider the uncertified issues.
Ill
Conclusion
Although I would not reason as the majority does in granting a broadened COA, I appreciate why it feels impelled to do so. However, having broadened Valerio’s COA to include all claims previously dismissed on procedural grounds, and having reversed the district court’s ruling on abuse of the writ and state-court procedural default, the court has revived all of Valerio’s guilt-phase claims including several that are unexhausted. The petition is now a mixed petition, which is subject to dismissal. I would not pick out one among many exhausted claims to make new constitutional law on, particularly when the claim that is singled out is a sentencing claim. There is no need to resolve whether the Nevada Supreme Court may, or did, cure an unconstitutionally vague aggravating-circumstance instruction unless and until it is determined that no writ shall issue on the guilt phase. But if the merits are reached, a state appellate court may sal*794vage a jury’s finding of an aggravating circumstance by a narrowing construction that applies to the facts of the case. The United States Supreme Court has said so repeatedly. Here, any rational factfinder could find that stabbing the victim forty-five times in clusters of eight on her head and neck and breasts and elsewhere was murder with torture or serious physical abuse. Accordingly, I would affirm the district court’s denial of the writ.
. This is so whether or not we have worked on the issue, for advisory opinions are to be avoided even at the cost of a "colossal waste of time." See op., supra at 770.
. Amicus takes a position closer to that adopted by the majority, as it argues that no Nevada court can make the finding of an aggravating circumstance in place of the jury under Apprendi v. New Jersey, 530 U.S. 466, 120 S.Ct. 2348, 147 L.Ed.2d 435 (2000). It also suggests that we could so hold on collateral review because Apprendi is a "watershed” rule, something we have since held we cannot do. United States v. Sanchez-Cervantes, 282 F.3d 664, 671 (9th Cir.2002). However, an issue raised only by an amicus, not by the parties, is not properly before the court. Reno v. Koray, 515 U.S. 50, 55 n. 2, 115 S.Ct. 2021, 132 L.Ed.2d 46 (1995); Russian River Watershed Prot. Comm. v. City of Santa Rosa, 142 F.3d 1136, 1141 (9th Cir.1998) ("We do not review issues raised only by an amicus curiae.”). In any event, the argument is not developed beyond the proposition just asserted, and no meaningful response has been addressed to it.
. Given the evidence of how and where Valer-io stabbed the victim, a rational factfinder could have found that she was subjected to torture and/ or serious physical abuse. Valer-io's argument that the repeated blows show panic or frenzy lacks any support in the record. Whether the Nevada Supreme Court failed to apply the Robins limiting construction correctly is a matter of state law for which federal habeas corpus relief does not lie. Jeffers, 497 U.S. at 780, 110 S.Ct. 3092. Likewise, the Nevada Supreme Court has held that it does not lack authority under state law to reweigh under Clemons. See Canape v. State, 109 Nev. 864, 859 P.2d 1023, 1034 (1993). It follows that it does not lack authority to conduct a harmless error review. That's what it had done in other cases, see, e.g. Robins, 798 P.2d at 564; Moran v. State, 103 Nev. 138, 734 P.2d 712, 714-15 (1987). And that’s what it did here, determining that the evidence supports the existence of the aggravating circumstance as properly defined.
. Although the majority’s opinion decides the issue on the assumption that Walton’s analysis of appellate review of death sentences controls, its approach is inevitably influenced by the view, which it also offers, that this aspect of Walton "is invalid under the rationale of Ring [.]” Op., supra at 756 n. 6. However, Ring makes clear that it overrules Walton only "in relevant part." Ring, - U.S. at -, 122 S.Ct. at 2432. The part that Ring overrules is the part that upheld Arizona's capital sentencing scheme on the footing that facts found by the judge qualified as sentencing considerations rather than as elements of the offense of capital murder. Ring found that this part of Walton is incompatible with Apprendi. But Ring does not overrule Walton to the extent that Walton has to do with appellate review of death sentences. See Ring, — U.S. at -, n. 4, 122 S.Ct. at 2437, n. 4. Overruling this part of Walton is for the Supreme Court to do, not for us. Meanwhile, Walton’s holding that a state appellate court may limit and save an unconstitutionally vague aggravating circumstance, and itself determine whether the evidence supports the existence of the aggravating circumstance, is alive and well. See Walton, 497 U.S. at 653-54, 110 S.Ct. 3047.
.We can put reweighing aside here, because there was nothing for the Nevada Supreme Court to reweigh. It did not toss out any aggravating circumstance, rather it upheld *784the aggravating circumstance that the jury found (the murder involved torture, depravity of mind, or mutilation) by narrowing it to torture and/or physical abuse. Thus, it engaged in harmless error review.
. The text from Walton upon which the majority relies states:
When a jury is the final sentencer, it is essential that the jurors be properly instructed regarding all facets of the sentencing process. It is not enough to instruct the jury in the bare terms of an aggravating circumstance that is unconstitutionally vague on its face. That is the import of our holdings in Maynard and Godfrey. But the logic of those cases has no place in the context of sentencing by a trial judge.
Walton, 497 U.S. at 653, 110 S.Ct. 3047 (emphasis added by the majority).
. The text from Pertgen upon which the majority relies is as follows:
*787Although the Court [in Walton ] upheld the imposition of a death sentence, Walton is factually distinguishable from the present case. In Walton, the death sentence was imposed by a trial judge, who is presumed to know the law and .to apply it in a constitutional manner. By contrast, in this case the death sentence was imposed by .a jury.
Pertgen, 875 P.2d at 366.
. Ever since Robins, the Nevada Supreme Court has construed NRS 200.033(8) as an aggravating circumstance where the murder involves torture or serious physical abuse, a term that it uses synonymously with mutilation. See, e.g., Jones v. State, 107 Nev. 632, 817 P.2d 1179, 1181 (1991) (before decision in Valerio); see also Smith v. State, 114 Nev. 33, 953 P.2d 264, 266 n. 3 (1998) (indicating Nevada Supreme Court practice since Robins ).
. The majority makes much of the fact that the state declined to argue that Valerio subjected the victim to torture, but that can't make a difference because the prosecutor's focus was on mutilation. His closing argued: "We have a body here, the body of Karen Sue Blackwell, which had 45 knife wounds, three, I can't remember the number, some abrasions to the top of the head. This body was mutilated, was it not from the top of the head to the vaginal area. That body was mutilated, pure and simple. That must be the definition of mutilation." Defense counsel likewise focused on mutilation, arguing: "Is it a mutilation worse than others? Well, this certainly is worse than you have in some murders, yeah. It’s not one gunshot wound. It's also not as bad as you have in some other cases. So you have to decide. No limbs were cut off. It's not one of those cases where you read in the paper the head was found separated from the body. It’s not one of the cases where you find words carved in the body. Is it mutilation? You have to decide."
. The court also granted a COA on a third ground, but Valerio does not pursue it on appeal.
. Normally arguments raised for the first time in a motion to reconsider, that could have been raised before, are waived. Beech Aircraft Corp. v. United States, 51 F.3d 834, 841 (9th Cir.1995).